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  • 1. Abdallah, J.
    et al.
    Adragna, P.
    Alexa, C.
    Alves, R.
    Amaral, P.
    Ananiev, A.
    Anderson, K.
    Andresen, X.
    Antonaki, A.
    Batusov, V.
    Bednar, P.
    Behrens, A.
    Bergeås, Elin
    Stockholm University, Faculty of Science, Department of Physics.
    Biscarat, C.
    Blanch, O.
    Blanchot, G.
    Blocki, J.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Boldea, V.
    Bosi, F.
    Bosman, M.
    Bromberg, C.
    Brunel, B.
    Budagov, J.
    Calderon, D.
    Calvet, D.
    Cardeira, C.
    Carli, T.
    Carvalho, J.
    Cascella, M.
    Castillo, M. V.
    Costello, J.
    Cavalli-Sforza, M.
    Cavasinni, V.
    Cerqueira, A. S.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. CERN, Geneva, Switzerland.
    Cobal, M.
    Cogswell, F.
    Constantinescu, S.
    Costanzo, D.
    Da Silva, P.
    David, M.
    Davidek, T.
    Dawson, J.
    De, K.
    Del Prete, T.
    Di Girolamo, B.
    Dita, S.
    Dolejsi, J.
    Dolezal, Z.
    Dotti, A.
    Downing, R.
    Drake, G.
    Efthymiopoulos, I.
    Errede, D.
    Errede, S.
    Farbin, A.
    Fassouliotis, D.
    Feng, E.
    Fenyuk, A.
    Ferdi, C.
    Ferreira, B. C.
    Ferrer, A.
    Ferrer, J.
    Flaminio, V.
    Flix, J.
    Francavilla, P.
    Fullana, E.
    Garde, V.
    Gaydee, J. C.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics.
    Giakoumopoulou, V.
    Giangiobbe, V.
    Gildemeister, O.
    Gilewsky, V.
    Giokaris, N.
    Gollub, N.
    Gomes, A.
    Gonzalez, V.
    Gouveia, J.
    Grenier, P.
    Gris, P.
    Grudzinski, J.
    Guarino, V.
    Guicheney, C.
    Gupta, A.
    Hakobyan, H.
    Haney, M.
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics.
    Henriques, A.
    Higon, E.
    Hill, N.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Hruska, I.
    Hurwitz, M.
    Huston, J.
    Jen-La Plante, I.
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics.
    Junk, T.
    Karyukhin, A.
    Khubua, J.
    Klereborn, Jonas
    Stockholm University, Faculty of Science, Department of Physics.
    Kopikov, S.
    Korolkov, I.
    Krivkova, P.
    Kulchitsky, Y.
    Kurochkin, Y.
    Kuzhir, P.
    Lapin, V.
    Lasseure, C.
    LeCompte, T.
    Lefevre, R.
    Leitner, R.
    Li, J.
    Lyablin, M.
    Lim, H.
    Lokajicek, M.
    Lomakin, Y.
    Lourtie, P.
    Lovas, L.
    Lupi, A.
    Maidantchik, C.
    Maio, A.
    Maliukov, S.
    Manousakis, A.
    Marques, C.
    Marroquim, F.
    Martin, F.
    Mazzoni, E.
    Mergelkuhl, D.
    Merritt, F.
    Miagkov, A.
    Miller, R.
    Minashvili, I.
    Miralles, L.
    Montarou, G.
    Nemecek, S.
    Nessi, M.
    Nikitine, I.
    Nodulman, L.
    Norniella, O.
    Nyman, T.
    Onofre, A.
    Oreglia, M.
    Palan, B.
    Pallin, D.
    Pantea, D.
    Pereira, A.
    Pilcher, J.
    Pina, J.
    Pinhao, J.
    Pod, E.
    Podlyski, F.
    Portell, X.
    Poveda, J.
    Pribyl, L.
    Price, L. E.
    Proudfoot, J.
    Ramalho, M.
    Ramstedt, Magnus
    Stockholm University, Faculty of Science, Department of Physics.
    Raposeiro, L.
    Reis, J.
    Richards, R.
    Roda, C.
    Romanov, V.
    Rose-Dulcina, L.
    Rosnet, P.
    Roy, P.
    Ruiz, A.
    Rumiantsau, V.
    Russakovich, N.
    da Costa, J. Sa
    Salto, O.
    Salvachua, B.
    Sanchis, E.
    Sanders, H.
    Santoni, C.
    Santos, J.
    Saraiva, J. G.
    Sarri, F.
    Says, L. -P
    Schlager, G.
    Schlereth, J.
    Seixas, J. M.
    Sellden, Björn
    Stockholm University, Faculty of Science, Department of Physics.
    Shalanda, N.
    Shchelchkov, A.
    Shevtsov, P.
    Shochet, M.
    Silva, J.
    Simaitis, V.
    Simonyan, M.
    Sissakian, A.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Skrzecz, F.
    Solans, C.
    Solodkov, A.
    Solovianov, O.
    Sorokina, J.
    Sosebee, M.
    Spano, F.
    Speckmeyer, P.
    Stanek, R.
    Starchenko, E.
    Starovoitov, P.
    Suk, M.
    Sykora, I.
    Tang, F.
    Tas, P.
    Teuscher, R.
    Tokar, S.
    Topilin, N.
    Torres, J.
    Underwood, D.
    Usai, G.
    Utkin, V.
    Valero, A.
    Valkar, S.
    Valls, J. A.
    Vartapetian, A.
    Vazeille, F.
    Vellidis, C.
    Ventura, F.
    Vichou, I.
    Vivarelli, I.
    Volpi, M.
    White, A.
    Wood, K.
    Zaitsev, A.
    Zenin, A.
    Zenis, T.
    Zenonos, Z.
    Zenz, S.
    Zilka, B.
    Mechanical construction and installation of the ATLAS tile calorimeter2013In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 8, p. T11001-Article in journal (Refereed)
    Abstract [en]

    This paper summarises the mechanical construction and installation of the Tile Calorimeter for the ATLAS experiment at the Large Hadron Collider in CERN, Switzerland. The Tile Calorimeter is a sampling calorimeter using scintillator as the sensitive detector and steel as the absorber and covers the central region of the ATLAS experiment up to pseudorapidities +/- 1.7. The mechanical construction of the Tile Calorimeter occurred over a period of about 10 years beginning in 1995 with the completion of the Technical Design Report and ending in 2006 with the installation of the final module in the ATLAS cavern. During this period approximately 2600 metric tons of steel were transformed into a laminated structure to form the absorber of the sampling calorimeter. Following instrumentation and testing, which is described elsewhere, the modules were installed in the ATLAS cavern with a remarkable accuracy for a structure of this size and weight.

  • 2. Abdallah, J.
    et al.
    Adragna, P.
    Alexa, C.
    Alves, R.
    Amaral, P.
    Ananiev, A.
    Anderson, K.
    Andresen, X.
    Antonaki, A.
    Batusov, V.
    Bednar, P.
    Bergeås, Elin
    Stockholm University, Faculty of Science, Department of Physics.
    Biscarat, C.
    Blanch, O.
    Blanchot, G.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Boldea, V.
    Bosi, F.
    Bosman, M.
    Bromberg, C.
    Budagov, J.
    Calvet, D.
    Cardeira, C.
    Carli, T.
    Carvalho, J.
    Cascella, M.
    Castillo, M. V.
    Costelo, J.
    Cavalli-Sforza, M.
    Cavasinni, V.
    Cerqueira, A. S.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics.
    Cobal, M.
    Cogswell, F.
    Constantinescu, S.
    Costanzo, D.
    Da Silva, P.
    David, M.
    Davidek, T.
    Dawson, J.
    De, K.
    Del Prete, T.
    Diakov, E.
    Di Girolamo, B.
    Dita, S.
    Dolejsi, J.
    Dolezal, Z.
    Dotti, A.
    Downing, R.
    Drake, G.
    Efthymiopoulos, I.
    Errede, D.
    Errede, S.
    Farbin, A.
    Fassouliotis, D.
    Feng, E.
    Fenyuk, A.
    Ferdi, C.
    Ferreira, B. C.
    Ferrer, A.
    Flaminio, V.
    Flix, J.
    Francavilla, P.
    Fullana, E.
    Garde, V.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics.
    Giakoumopoulou, V.
    Giangiobbe, V.
    Gildemeister, O.
    Gilewsky, V.
    Giokaris, N.
    Gollub, N.
    Gomes, A.
    Gonzalez, V.
    Gouveia, J.
    Grenier, P.
    Gris, P.
    Guarino, V.
    Guicheney, C.
    Gupta, A.
    Hakobyan, H.
    Haney, M.
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics.
    Henriques, A.
    Higon, E.
    Hill, N.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Hruska, I.
    Hurwitz, M.
    Huston, J.
    Plante, I. Jen-La
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics.
    Junk, T.
    Karyukhin, A.
    Khubua, J.
    Klereborn, Jonas
    Stockholm University, Faculty of Science, Department of Physics.
    Konstantinov, V.
    Kopikov, S.
    Korolkov, I.
    Krivkova, P.
    Kulchitsky, Y.
    Kurochkin, Yu
    Kuzhir, P.
    Lapin, V.
    LeCompte, T.
    Lefevre, R.
    Leitner, R.
    Li, J.
    Liablin, M.
    Lokajicek, M.
    Lomakin, Y.
    Lourtie, P.
    Lovas, L.
    Lupi, A.
    Maidantchik, C.
    Maio, A.
    Maliukov, S.
    Manousakis, A.
    Marques, C.
    Marroquim, F.
    Martin, F.
    Mazzoni, E.
    Merritt, F.
    Miagkov, A.
    Miller, R.
    Minashvili, I.
    Miralles, L.
    Montarou, G.
    Nemecek, S.
    Nessi, M.
    Nikitine, I.
    Nodulman, L.
    Norniella, O.
    Onofre, A.
    Oreglia, M.
    Palan, B.
    Pallin, D.
    Pantea, D.
    Pereira, A.
    Pilcher, J.
    Pina, J.
    Pinhao, J.
    Pod, E.
    Podlyski, F.
    Portell, X.
    Poveda, J.
    Pribyl, L.
    Price, E.
    Proudfoot, J.
    Ramalho, M.
    Ramstedt, Magnus
    Stockholm University, Faculty of Science, Department of Physics.
    Raposeiro, L.
    Reis, J.
    Richards, R.
    Roda, C.
    Romanov, V.
    Rosnet, P.
    Roy, P.
    Ruiz, A.
    Rumiantsau, V.
    Russakovich, N.
    Da Costa, J. Sa
    Salto, O.
    Salvachua, B.
    Sanchis, E.
    Sanders, H.
    Santoni, C.
    Santos, J.
    Saraiva, J. G.
    Sarri, F.
    Says, L. -P
    Schlager, G.
    Schlereth, J.
    Seixas, J. M.
    Sellden, Björn
    Stockholm University, Faculty of Science, Department of Physics.
    Shalanda, N.
    Shevtsov, P.
    Shochet, M.
    Silva, J.
    Simaitis, V.
    Simonyan, M.
    Sissakian, A.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Solans, C.
    Solodkov, A.
    Solovianov, O.
    Sosebee, M.
    Spano, F.
    Speckmeyer, P.
    Stanek, R.
    Starchenko, E.
    Starovoitov, P.
    Suk, M.
    Sykora, I.
    Tang, F.
    Tas, P.
    Teuscher, R.
    Tischenko, M.
    Tokar, S.
    Topilin, N.
    Torres, J.
    Underwood, D.
    Usai, G.
    Valero, A.
    Valkar, S.
    Valls, J. A.
    Vartapetian, A.
    Vazeille, F.
    Vellidis, C.
    Ventura, F.
    Vichou, I.
    Vivarelli, I.
    Volpi, M.
    White, A.
    Zaitsev, A.
    Zaytsev, Yu
    Zenin, A.
    Zenis, T.
    Zenonos, Z.
    Zenz, S.
    Zilka, B.
    The optical instrumentation of the ATLAS Tile Calorimeter2013In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 8, p. P01005-Article in journal (Refereed)
    Abstract [en]

    The Tile Calorimeter, covering the central region of the ATLAS experiment up to pseudorapidities of +/-1.7, is a sampling device built with scintillating tiles that alternate with iron plates. The light is collected in wave-length shifting (WLS) fibers and is read out with photomultipliers. In the characteristic geometry of this calorimeter the tiles lie in planes perpendicular to the beams, resulting in a very simple and modular mechanical and optical layout. This paper focuses on the procedures applied in the optical instrumentation of the calorimeter, which involved the assembly of about 460,000 scintillator tiles and 550,000 WLS fibers. The outcome is a hadronic calorimeter that meets the ATLAS performance requirements, as shown in this paper.

  • 3. Abdallah, J.
    et al.
    Alexa, C.
    Amaral Coutinho, Y.
    Amor Dos Santos, S. P.
    Anderson, K. J.
    Arabidze, G.
    Araque, J. P.
    Artamonov, A.
    Asquith, L.
    Astalos, R.
    Mayes, J. Backus
    Bartos, P.
    Batkova, L.
    Bertolucci, F.
    Bessidskaia Bylund, Olga
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Blanco Castro, A.
    Blazek, T.
    Bohm, Christian
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Boumediene, D.
    Boveia, A.
    Brown, H.
    Busato, E.
    Calkins, R.
    Calvet, D.
    Calvet, S.
    Toro, R. Camacho
    Caminal Armadans, R.
    Carli, T.
    Carvalho, J.
    Cascella, M.
    Castro, N. F.
    Cavasinni, V.
    Cerqueira, A. S.
    Chadelas, R.
    Chakraborty, D.
    Chekanov, S.
    Chen, X.
    Chikovani, L.
    Choudalakis, G.
    Cinca, D.
    Ciubancan, M.
    Clément, Christophe
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cole, S.
    Constantinescu, S.
    Costin, T.
    Crouau, M.
    Crozatier, C.
    Cuciuc, C. -M.
    Da Cunha Sargedas De Sousa, M. J.
    Darmora, S.
    Davidek, T.
    Del Prete, T.
    Dita, S.
    Djobava, T.
    Dolejsi, J.
    Dotti, A.
    Dubreuil, E.
    Dunford, M.
    Eriksson, Daniel
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Errede, S.
    Errede, D.
    Faltova, J.
    Farbin, A.
    Febbraro, R.
    Federic, P.
    Feng, E. J.
    Ferrer, A.
    Fiascaris, M.
    Fiolhais, M. C. N.
    Fiorini, L.
    Francavilla, P.
    Torregrosa, E. Fullana
    Galhardo, B.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ghodbane, N.
    Giakoumopoulou, V.
    Giangiobbe, V.
    Giokaris, N.
    Glonti, G. L.
    Gomes, A.
    Gonzalez Parra, G.
    Grenier, P.
    Grinstein, S.
    Gris, Ph.
    Guicheney, C.
    Hakobyan, H.
    Hard, A. S.
    Harkusha, S.
    Heelan, L.
    Helsens, C.
    Correia, A. M. Henriques
    Hernandez Jimenez, Y.
    Hernandez, C. M.
    Hign-Rodriguez, E.
    Hurwitz, M.
    Huseynov, N.
    Huston, J.
    Plante, I. Jen-La
    Jennens, D.
    Johansson, K. Erik
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jorge, P. M.
    Juste Rozas, A.
    Kapliy, A.
    Karpov, S. N.
    Karyukhin, A. N.
    Khandanyan, Hovhannes
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Khramov, E.
    Khubua, J.
    Kim, Hyeon
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Klimek, Pawel
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Korolkov, I.
    Kruse, A.
    Kulchitsky, Y.
    Kurochkin, Y. A.
    Lafarguette, P.
    Lambert, D.
    LeCompte, T.
    Leitner, R.
    Leone, S.
    Liao, H.
    Lie, K.
    Lokajicek, M.
    Lundberg, Olof
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Magalhaes Martins, P. J.
    Maio, A.
    Makouski, M.
    Maneira, J.
    Manhaes de Andrade Filho, L.
    Manousakis-Katsikakis, A.
    Martin, B.
    Mchedlidze, G.
    Meehan, S.
    Garcia, B. R. Mellado
    Meoni, E.
    Merritt, F. S.
    Meyer, C.
    Miller, D. W.
    Milstead, David A.
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Minashvili, I. A.
    Mir, L. M.
    Molander, Simon
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Montejo Berlingen, J.
    Mosidze, M.
    Myagkov, A. G.
    Nemecek, S.
    Nepomuceno, A. A.
    Nguyen, D. H.
    Nikolaenko, V.
    Nilsson, P.
    Nodulman, L.
    Nordkvist, Björn
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ohm, C. C.
    Olariu, A.
    Oleiro Seabra, L. F.
    Onofre, A.
    Oreglia, M. J.
    Pallin, D.
    Pantea, D.
    Hernandez, D. Paredes
    Morales, M. I. Pedraza
    Pedro, R.
    Martins, F. M. Pedro
    Peng, H.
    Penning, B.
    Pilcher, J. E.
    Pina, J.
    Pleskot, V.
    Plotnikova, E.
    Podlyski, F.
    Popeneciu, G. A.
    Poveda, J.
    Pravahan, R.
    Pribyl, L.
    Price, L. E.
    Proudfoot, J.
    Rocha de Lima, J. G.
    Roda, C.
    Dos Santos, D. Roda
    Saez, S. M. Romano
    Rossetti, V.
    Ruiz-Martinez, A.
    Rusakovich, N. A.
    Ferrando, B. M. Salvachua
    Santoni, C.
    Santos, H.
    Saraiva, J. G.
    Says, L. P.
    Schwartzman, A.
    Scuri, F.
    Shimizu, S.
    Silva, J.
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Solans, C. A.
    Solodkov, A. A.
    Solovyanov, O. V.
    Spalla, M.
    Stanek, R. W.
    Starchenko, E. A.
    Starovoitov, P.
    Stavina, P.
    Stoicea, G.
    Succurro, A.
    Suhr, C.
    Sumida, T.
    Sykora, I.
    Tas, P.
    Tavares Delgado, A.
    Tokar, S.
    Tsiareshka, P. V.
    Tsiskaridze, V.
    Tudorache, V.
    Tudorache, A.
    Tuggle, J. M.
    Tylmad, Maja
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Usai, G.
    Valero, A.
    Valery, L.
    Valladolid Gallego, E.
    Valls Ferrer, J. A.
    Vazeille, F.
    Veloso, F.
    Vichou, I.
    Vinogradov, V. B.
    Viret, S.
    Volpi, M.
    Wang, C.
    Weng, Z.
    White, A.
    Wilkens, H. G.
    Yanush, S.
    Yoshida, R.
    Zhang, L.
    Zhu, Y.
    Zinonos, Z.
    Zutshi, V.
    Zenis, T.
    van Woerden, M. C.
    The Laser calibration of the ATLAS Tile Calorimeter during the LHC run 12016In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 11, article id T10005Article in journal (Refereed)
    Abstract [en]

    This article describes the Laser calibration system of the ATLAS hadronic Tile Calorimeter that has been used during the run 1 of the LHC. First, the stability of the system associated readout electronics is studied. It is found to be stable with variations smaller than 0.6 %. Then, the method developed to compute the calibration constants, to correct for the variations of the gain of the calorimeter photomultipliers, is described. These constants were determined with a statistical uncertainty of 0.3 % and a systematic uncertainty of 0.2 % for the central part of the calorimeter and 0.5 % for the end-caps. Finally, the detection and correction of timing mis-configuration of the Tile Calorimeter using the Laser system are also presented.

  • 4.
    Abulaiti, Yiming
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åkerstedt, Henrik
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bendtz, Katarina
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bertoli, Gabriele
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bessidskaia Bylund, Olga
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Carney, Rebecca M. D.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Clement, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cribbs, Wayne A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Molander, Simon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Pöttgen, Ruth
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Rossetti, Valerio
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Shaikh, Nabila W.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Shcherbakova, Anna
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Strandberg, Sara
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ughetto, Michaël
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Valdes Santurio, Eduardo
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Wallängen, Veronica
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Performance of the ATLAS Transition Radiation Tracker in Run 1 of the LHC: tracker properties2017In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 12, article id P05002Article in journal (Refereed)
    Abstract [en]

    The tracking performance parameters of the ATLAS Transition Radiation Tracker (TRT) as part of the ATLAS inner detector are described in this paper for different data-taking conditions in proton-proton, proton-lead and lead-lead collisions at the Large Hadron Collider (LHC). The performance is studied using data collected during the first period of LHC operation (Run 1) and is compared with Monte Carlo simulations. The performance of the TRT, operating with two different gas mixtures (xenon-based and argon-based) and its dependence on the TRT occupancy is presented. These studies show that the tracking performance of the TRT is similar for the two gas mixtures and that a significant contribution to the particle momentum resolution is made by the TRT up to high particle densities.

  • 5.
    Abulaiti, Yiming
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åkerstedt, Henrik
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bendtz, Katarina
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bertoli, Gabriele
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bessidskaia Bylund, Olga
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Carney, Rebecca M. D.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cribbs, Wayne A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Molander, Simon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Pöttgen, Ruth
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Shaikh, Nabila W.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Shcherbakova, Anna
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Strandberg, Sara
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ughetto, Michaël
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Valdes Santurio, Eduardo
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Wallängen, Veronica
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Study of the material of the ATLAS inner detector for Run 2 of the LHC2017In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 12, article id P12009Article in journal (Refereed)
    Abstract [en]

    The ATLAS inner detector comprises three different sub-detectors: the pixel detector, the silicon strip tracker, and the transition-radiation drift-tube tracker. The Insertable B-Layer, a new innermost pixel layer, was installed during the shutdown period in 2014, together with modifications to the layout of the cables and support structures of the existing pixel detector. The material in the inner detector is studied with several methods, using a low-luminosity root s = 13 TeV pp collision sample corresponding to around 2.0 nb(-1) collected in 2015 with the ATLAS experiment at the LHC. In this paper, the material within the innermost barrel region is studied using reconstructed hadronic interaction and photon conversion vertices. For the forward rapidity region, the material is probed by a measurement of the efficiency with which single tracks reconstructed from pixel detector hits alone can be extended with hits on the track in the strip layers. The results of these studies have been taken into account in an improved description of the material in the ATLAS inner detector simulation, resulting in a reduction in the uncertainties associated with the charged-particle reconstruction efficiency determined from simulation.

  • 6.
    Abulaiti, Yiming
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åkerstedt, Henrik
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bendtz, Katarina
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bertoli, Gabriele
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bessidskaia Bylund, Olga
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Clement, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cribbs, Wayne A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Khandanyan, Hovhannes
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Kim, Heyon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Klimek, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Molander, Simon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Pani, Priscilla
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Petridis, Andreas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Plucinski, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Pöttgen, Ruth
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Rossetti, Valerio
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Shcherbakova, Anna
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Strandberg, Sara
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Tylmad, Maja
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ughetto, Michaël
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Modelling Z -> tau tau processes in ATLAS with tau-embedded Z -> mu mu data2015In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 10, article id P09018Article in journal (Refereed)
    Abstract [en]

    This paper describes the concept, technical realisation and validation of a largely data-driven method to model events with Z -> tau tau decays. In Z -> mu mu events selected from proton-proton collision data recorded at root s = 8 TeV with the ATLAS experiment at the LHC in 2012, the Z decay muons are replaced by tau leptons from simulated Z -> tau tau decays at the level of reconstructed tracks and calorimeter cells. The tau lepton kinematics are derived from the kinematics of the original muons. Thus, only the well-understood decays of the Z boson and tau leptons as well as the detector response to the tau decay products are obtained from simulation. All other aspects of the event, such as the Z boson and jet kinematics as well as effects from multiple interactions, are given by the actual data. This so-called tau-embedding method is particularly relevant for Higgs boson searches and analyses in tau tau final states, where Z -> tau tau decays constitute a large irreducible background that cannot be obtained directly from data control samples. In this paper, the relevant concepts are discussed based on the implementation used in the ATLAS Standard Model H -> tau tau analysis of the full datataset recorded during 2011 and 2012.

  • 7.
    Abulaiti, Yiming
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åkerstedt, Henrik
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bendtz, Katarina
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bertoli, Gabriele
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bessidskaia Bylund, Olga
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cribbs, Wayne A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Khandanyan, Hovhannes
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Kim, Hyeon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Klimek, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Molander, Simon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Pani, Priscilla
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Petridis, Andreas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Plucinski, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Rossetti, Valerio
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Shcherbakova, Anna
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Strandberg, Sara
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Tylmad, Maja
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ughetto, Michaël
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Performance of b-jet identification in the ATLAS experiment2016In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 11, article id P04008Article in journal (Refereed)
    Abstract [en]

    The identification of jets containing b hadrons is important for the physics programme of the ATLAS experiment at the Large Hadron Collider. Several algorithms to identify jets containing b hadrons are described, ranging from those based on the reconstruction of an inclusive secondary vertex or the presence of tracks with large impact parameters to combined tagging algorithms making use of multi-variate discriminants. An independent b-tagging algorithm based on the reconstruction of muons inside jets as well as the b-tagging algorithm used in the online trigger are also presented. The b-jet tagging efficiency, the c-jet tagging efficiency and the mistag rate for light flavour jets in data have been measured with a number of complementary methods. The calibration results are presented as scale factors defined as the ratio of the efficiency (or mistag rate) in data to that in simulation. In the case of b jets, where more than one calibration method exists, the results from the various analyses have been combined taking into account the statistical correlation as well as the correlation of the sources of systematic uncertainty.

  • 8.
    Abulaiti, Yiming
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åkerstedt, Henrik
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bendtz, Katarina
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bertoli, Gabriele
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bessidskaia Bylund, Olga
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cribbs, Wayne A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Khandanyan, Hovhannes
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Klimek, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Molander, Simon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Pani, Priscilla
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Plucinski, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Pöttgen, Ruth
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Rossetti, Valerio
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Shaikh, Nabila W.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Shcherbakova, Anna
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Strandberg, Sara
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ughetto, Michaël
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Valdes Santurio, Eduardo
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Wallängen, Veronica
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Beam-induced and cosmic-ray backgrounds observed in the ATLAS detector during the LHC 2012 proton-proton running period2016In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 11, article id P05013Article in journal (Refereed)
    Abstract [en]

    This paper discusses various observations on beam-induced and cosmic-ray backgrounds in the ATLAS detector during the LHC 2012 proton-proton run. Building on published results based on 2011 data, the correlations between background and residual pressure of the beam vacuum are revisited. Ghost charge evolution over 2012 and its role for backgrounds are evaluated. New methods to monitor ghost charge with beam-gas rates are presented and observations of LHC abort gap population by ghost charge are discussed in detail. Fake jets from colliding bunches and from ghost charge are analysed with improved methods, showing that ghost charge in individual radio-frequency buckets of the LHC can be resolved. Some results of two short periods of dedicated cosmic-ray background data-taking are shown; in particular cosmic-ray muon induced fake jet rates are compared to Monte Carlo simulations and to the fake jet rates from beam background. A thorough analysis of a particular LHC fill, where abnormally high background was observed, is presented. Correlations between backgrounds and beam intensity losses in special fills with very high beta* are studied.

  • 9.
    Abulaiti, Yiming
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åkerstedt, Henrik
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bendtz, Katarina
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bertoli, Gabriele
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bessidskaia Bylund, Olga
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cribbs, Wayne A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Molander, Simon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Pani, Priscilla
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Pöttgen, Ruth
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Rossetti, Valerio
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Shaikh, Nabila W.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Shcherbakova, Anna
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Strandberg, Sara
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ughetto, Michaël
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Valdes Santurio, Eduardo
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Wallängen, Veronica
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    A measurement of material in the ATLAS tracker using secondary hadronic interactions in 7 TeV p p collisions2016In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 11, article id P11020Article in journal (Refereed)
    Abstract [en]

    Knowledge of the material in the ATLAS inner tracking detector is crucial in under-standing the reconstruction of charged-particle tracks, the performance of algorithms that identify jets containing b-hadrons and is also essential to reduce background in searches for exotic particles that can decay within the inner detector volume. Interactions of primary hadrons produced in pp collisions with the material in the inner detector are used to map the location and amount of this material. The hadronic interactions of primary particles may result in secondary vertices, which in this analysis are reconstructed by an inclusive vertex-finding algorithm. Data were collected using minimum-bias triggers by the ATLAS detector operating at the LHC during 2010 at centre-of-mass energy root s = 7 TeV, and correspond to an integrated luminosity of 19 nb(-1). Kinematic properties of these secondary vertices are used to study the validity of the modelling of hadronic interactions in simulation. Secondary-vertex yields are compared between data and simulation over a volume of about 0.7m(3) around the interaction point, and agreement is found within overall uncertainties.

  • 10.
    Abulaiti, Yiming
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åkerstedt, Henrik
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bendtz, Katarina
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bertoli, Gabriele
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bessidskaia, Olga
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cribbs, Wayne A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Eriksson, Daniel
    Stockholm University, Faculty of Science, Department of Physics.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Johansson, K. Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Khandanyan, Hovhannes
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Kim, Hyeon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Klimek, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Molander, Simon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ohm, Christian C.
    CERN, Geneva, Switzerland.
    Petridis, Andreas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Plucinski, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Rossetti, Valerio
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Strandberg, Sara
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Tylmad, Maja
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    A neural network clustering algorithm for the ATLAS silicon pixel detector2014In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 9, p. P09009-Article in journal (Refereed)
    Abstract [en]

    A novel technique to identify and split clusters created by multiple charged particles in the ATLAS pixel detector using a set of artificial neural networks is presented. Such merged clusters are a common feature of tracks originating from highly energetic objects, such as jets. Neural networks are trained using Monte Carlo samples produced with a detailed detector simulation. This technique replaces the former clustering approach based on a connected component analysis and charge interpolation. The performance of the neural network splitting technique is quantified using data from proton-proton collisions at the LHC collected by the ATLAS detector in 2011 and from Monte Carlo simulations. This technique reduces the number of clusters shared between tracks in highly energetic jets by up to a factor of three. It also provides more precise position and error estimates of the clusters in both the transverse and longitudinal impact parameter resolution.

  • 11.
    Abulaiti, Yiming
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bendtz, Katarina
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bessidskaia, Olga
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Eriksson, Daniel
    Stockholm University, Faculty of Science, Department of Physics.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Johansson, K. Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Khandanyan, Hovhannes
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Kim, Hyeon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Klimek, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Johan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Molander, Simon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ohm, Christian C.
    CERN, Geneva, Switzerland.
    Petridis, Andreas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Plucinski, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Rossetti, Valerio
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Strandberg, Sara
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Tylmad, Maja
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Standalone vertex finding in the ATLAS muon spectrometer2014In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 9, p. P02001-Article in journal (Refereed)
    Abstract [en]

    A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to b (b) over bar final states, and pp collision data at root s = 7 TeV collected with the ATLAS detector at the LHC during 2011.

  • 12.
    Abulaiti, Yiming
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bendtz, Katarina
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bessidskaia, Olga
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Eriksson, Daniel
    Stockholm University, Faculty of Science, Department of Physics.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Johansson, K. Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Khandanyan, Hovhannes
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Kim, Hyeon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Klimek, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Molander, Simon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ohm, Christian C.
    CERN, Switzerland.
    Petridis, Andreas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Plucinski, Pavel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Rossetti, Valerio
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Strandberg, Sara
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Tylmad, Maja
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Monitoring and data quality assessment of the ATLAS liquid argon calorimeter2014In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 9, p. P07024-Article in journal (Refereed)
    Abstract [en]

    The liquid argon calorimeter is a key component of the ATLAS detector installed at the CERN Large Hadron Collider. The primary purpose of this calorimeter is the measurement of electron and photon kinematic properties. It also provides a crucial input for measuring jets and missing transverse momentum. An advanced data monitoring procedure was designed to quickly identify issues that would affect detector performance and ensure that only the best quality data are used for physics analysis. This article presents the validation procedure developed during the 2011 and 2012 LHC data-taking periods, in which more than 98% of the proton-proton luminosity recorded by ATLAS at a centre-of-mass energy of 7-8 TeV had calorimeter data quality suitable for physics analysis.

  • 13.
    Abulaiti, Yiming
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bendtz, Katarina
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bessidskaia, Olga
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Eriksson, Daniel
    Stockholm University, Faculty of Science, Department of Physics.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Johansson, K. Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Khandanyan, Hovhannes
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Kim, Hyeon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Klimek, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Molander, Simon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ohm, Christian C.
    CERN, Geneva, Switzerland.
    Petridis, Andreas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Plucinski, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Rossetti, Valerio
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Strandberg, Sara
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Tylmad, Maja
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Operation and performance of the ATLAS semiconductor tracker2014In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 9Article in journal (Refereed)
    Abstract [en]

    The semiconductor tracker is a silicon microstrip detector forming part of the inner tracking system of the ATLAS experiment at the LHC. The operation and performance of the semiconductor tracker during the first years of LHC running are described. More than 99% of the detector modules were operational during this period, with an average intrinsic hit efficiency of (99.74 +/- 0.04)%. The evolution of the noise occupancy is discussed, and measurements of the Lorentz angle, delta-ray production and energy loss presented. The alignment of the detector is found to be stable at the few-micron level over long periods of time. Radiation damage measurements, which include the evolution of detector leakage currents, are found to be consistent with predictions and are used in the verification of radiation background simulations.

  • 14.
    Abulaiti, Yiming
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bendtz, Katarina
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Eriksson, Daniel
    Stockholm University, Faculty of Science, Department of Physics.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Johansen, Marianne
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Johansson, K. Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Khandanyan, Hovhannes
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Kim, Hyeon Jin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Klimek, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Johan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ohm, Christian C.
    CERN.
    Papadelis, Aras
    Stockholm University, Faculty of Science, Department of Physics.
    Petridis, Andreas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Plucinski, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Silverstein, Samuel
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Strandberg, Sara
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Tylmad, Maja
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Yang, Zhaoyu
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Triggers for displaced decays of long-lived neutral particles in the ATLAS detector2013In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 8, p. P07015-Article in journal (Refereed)
    Abstract [en]

    A set of three dedicated triggers designed to detect long-lived neutral particles decaying throughout the ATLAS detector to a pair of hadronic jets is described. The efficiencies of the triggers for selecting displaced decays as a function of the decay position are presented for simulated events. The effect of pile-up interactions on the trigger efficiencies and the dependence of the trigger rate on instantaneous luminosity during the 2012 data-taking period at the LHC are discussed.

  • 15.
    Ahrens, Maryon
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Dumm, Jonathan P.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Finley, Chad
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Flis, Samuel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hulth, Per Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Thollander, Lars
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Walck, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Wolf, Martin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Zoll, Marcel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    The IceCube Neutrino Observatory: instrumentation and online systems2017In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 12, article id P03012Article in journal (Refereed)
    Abstract [en]

    The IceCube Neutrino Observatory is a cubic-kilometer-scale high-energy neutrino detector built into the ice at the South Pole. Construction of IceCube, the largest neutrino detector built to date, was completed in 2011 and enabled the discovery of high-energy astrophysical neutrinos. We describe here the design, production, and calibration of the IceCube digital optical module (DOM), the cable systems, computing hardware, and our methodology for drilling and deployment. We also describe the online triggering and data filtering systems that select candidate neutrino and cosmic ray events for analysis. Due to a rigorous pre-deployment protocol, 98.4% of the DOMs in the deep ice are operating and collecting data. IceCube routinely achieves a detector uptime of 99% by emphasizing software stability and monitoring. Detector operations have been stable since construction was completed, and the detector is expected to operate at least until the end of the next decade.

  • 16.
    Ahrens, Maryon
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Dumm, Jonathan P.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Finley, Chad
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Flis, Samuel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Walck, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Wolf, Michael
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Zoll, Marcel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). South Dakota School of Mines and Technology, U.S.A..
    Very high-energy gamma-ray follow-up program using neutrino triggers from IceCube2016In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 11, article id P11009Article in journal (Refereed)
    Abstract [en]

    We describe and report the status of a neutrino-triggered program in IceCube that generates real-time alerts for gamma-ray follow-up observations by atmospheric-Cherenkov telescopes (MAGIC and VERITAS). While IceCube is capable of monitoring the whole sky continuously, high-energy gamma-ray telescopes have restricted fields of view and in general are unlikely to be observing a potential neutrino-flaring source at the time such neutrinos are recorded. The use of neutrino-triggered alerts thus aims at increasing the availability of simultaneous multi-messenger data during potential neutrino flaring activity, which can increase the discovery potential and constrain the phenomenological interpretation of the high-energy emission of selected source classes (e. g. blazars). The requirements of a fast and stable online analysis of potential neutrino signals and its operation are presented, along with first results of the program operating between 14 March 2012 and 31 December 2015.

  • 17. Akmete, A.
    et al.
    Alexandrov, A.
    Anokhina, A.
    Aoki, S.
    Atkin, E.
    Azorskiy, N.
    Back, J. J.
    Bagulya, A.
    Baranov, A.
    Barker, G. J.
    Bay, A.
    Bayliss, V.
    Bencivenni, G.
    Berdnikov, A. Y.
    Berdnikov, Y. A.
    Bertani, M.
    Betancourt, C.
    Bezshyiko, I.
    Bezshyyko, O.
    Bick, D.
    Bieschke, S.
    Blanco, A.
    Boehm, J.
    Bogomilov, M.
    Bondarenko, K.
    Bonivento, W. M.
    Boyarsky, A.
    Brenner, R.
    Breton, D.
    Brundler, R.
    Bruschi, M.
    Buscher, V.
    Buonaura, A.
    Buontempo, S.
    Cadeddu, S.
    Calcaterra, A.
    Campanelli, M.
    Chauveau, J.
    Chepurnov, A.
    Chernyavsky, M.
    Choi, K. -Y.
    Chumakov, A.
    Ciambrone, P.
    Dallavalle, G. M.
    D'Ambrosio, N.
    D'Appollonio, G.
    De Lellis, G.
    De Roeck, A.
    De Serio, M.
    Dedenko, L.
    Di Crescenzo, A.
    Di Marco, N.
    Dib, C.
    Dijkstra, H.
    Dmitrenko, V.
    Domenici, D.
    Donskov, S.
    Dubreuil, A.
    Ebert, J.
    Enik, T.
    Etenko, A.
    Fabbri, F.
    Fabbri, L.
    Fedin, O.
    Fedorova, G.
    Felici, G.
    Ferro-Luzzi, M.
    Fini, R. A.
    Fonte, P.
    Franco, C.
    Fukuda, T.
    Galati, G.
    Gavrilov, G.
    Gerlach, S.
    Golinka-Bezshyyko, L.
    Golubkov, D.
    Golutvin, A.
    Gorbunov, D.
    Gorbunov, S.
    Gorkavenko, V.
    Gornushkin, Y.
    Gorshenkov, M.
    Grachev, V.
    Graverini, E.
    Grichine, V.
    Guler, A. M.
    Guz, Yu.
    Hagner, C.
    Hakobyan, H.
    van Herwijnen, E.
    Hollnagel, A.
    Hosseini, B.
    Hushchyn, M.
    Iaselli, G.
    Iuliano, A.
    Jacobsson, R.
    Jonker, M.
    Kadenko, I.
    Kamiscioglu, C.
    Kamiscioglu, M.
    Khabibullin, M.
    Khaustov, G.
    Khotyantsev, A.
    Kim, S. H.
    Kim, V.
    Kim, Y. G.
    Kitagawa, N.
    Ko, J. -W.
    Kodama, K.
    Kolesnikov, A.
    Kolev, D. I.
    Kolosov, V.
    Komatsu, M.
    Konovalova, N.
    Korkmaz, M. A.
    Korol, I.
    Korol'ko, I.
    Korzenev, A.
    Kovalenko, S.
    Krasilnikova, I.
    Krivova, K.
    Kudenko, Y.
    Kurochka, V.
    Kuznetsova, E.
    Lacker, H. M.
    Lai, A.
    Lanfranchi, G.
    Lantwin, O.
    Lauria, A.
    Lebbolo, H.
    Lee, K. Y.
    Levy, J. -M.
    Lopes, L.
    Lyubovitskij, V.
    Maalmi, J.
    Magnan, A.
    Maleev, V.
    Malinin, A.
    Mefodev, A.
    Mermod, P.
    Mikado, S.
    Mikhaylov, Yu.
    Milstead, David A.
    Stockholm University, Faculty of Science, Department of Physics.
    Mineev, O.
    Montanari, A.
    Montesi, M. C.
    Morishima, K.
    Movchan, S.
    Naganawa, N.
    Nakamura, M.
    Nakano, T.
    Novikov, A.
    Obinyakov, B.
    Ogawa, S.
    Okateva, N.
    Owen, P. H.
    Paoloni, A.
    Park, B. D.
    Paparella, L.
    Pastore, A.
    Patel, M.
    Pereyma, D.
    Petrenko, D.
    Petridis, K.
    Podgrudkov, D.
    Poliakov, V.
    Polukhina, N.
    Prokudin, M.
    Prota, A.
    Rademakers, A.
    Ratnikov, F.
    Rawlings, T.
    Razeti, M.
    Redi, F.
    Ricciardi, S.
    Roganova, T.
    Rogozhnikov, A.
    Rokujo, H.
    Rosa, G.
    Rovelli, T.
    Ruchayskiy, O.
    Ruf, T.
    Samoylenko, V.
    Saputi, A.
    Sato, O.
    Savchenko, E. S.
    Schmidt-Parzefall, W.
    Serra, N.
    Shakin, A.
    Shaposhnikov, M.
    Shatalov, P.
    Shchedrina, T.
    Shchutska, L.
    Shevchenko, V.
    Shibuya, H.
    Shustov, A.
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Simone, S.
    Skorokhvatov, M.
    Smirnov, S.
    Sohn, J. Y.
    Sokolenko, A.
    Starkov, N.
    Storaci, B.
    Strolin, P.
    Takahashi, S.
    Timiryasov, I.
    Tioukov, V.
    Tosi, N.
    Treille, D.
    Tsenov, R.
    Ulin, S.
    Ustyuzhanin, A.
    Uteshev, Z.
    Vankova-Kirilova, G.
    Vannucci, F.
    Venkova, P.
    Vilchinski, S.
    Villa, M.
    Vlasik, K.
    Volkov, A.
    Voronkov, R.
    Wanke, R.
    Woo, J. -K.
    Wurm, M.
    Xella, S.
    Yilmaz, D.
    Yilmazer, A. U.
    Yoon, C. S.
    Zaytsev, Yu.
    The active muon shield in the SHiP experiment2017In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 12, article id P05011Article in journal (Refereed)
    Abstract [en]

    The SHiP experiment is designed to search for very weakly interacting particles beyond the Standard Model which are produced in a 400 GeV/c proton beam dump at the CERN SPS. An essential task for the experiment is to keep the Standard Model background level to less than 0.1 event after 2 x 10(20) protons on target. In the beam dump, around 10(11) muons will be produced per second. The muon rate in the spectrometer has to be reduced by at least four orders of magnitude to avoid muon-induced combinatorial background. A novel active muon shield is used to magnetically deflect the muons out of the acceptance of the spectrometer. This paper describes the basic principle of such a shield, its optimization and its performance.

  • 18.
    Algeri, Sara
    et al.
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Imperial College London, UK..
    van Dyk, D. A.
    Conrad, Jan
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Imperial College London, UK..
    Anderson, Brandon
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    On methods for correcting for the look-elsewhere effect in searches for new physics2016In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 11, article id P12010Article in journal (Refereed)
    Abstract [en]

    The search for new significant peaks over a energy spectrum often involves a statistical multiple hypothesis testing problem. Separate tests of hypothesis are conducted at different locations over a fine grid producing an ensemble of local p-values, the smallest of which is reported as evidence for the new resonance. Unfortunately, controlling the false detection rate (type I error rate) of such procedures may lead to excessively stringent acceptance criteria. In the recent physics literature, two promising statistical tools have been proposed to overcome these limitations. In 2005, a method to find needles in haystacks was introduced by Pilla et al. [1], and a second method was later proposed by Gross and Vitells [2] in the context of the look-elsewhere effect and trial factors. We show that, although the two methods exhibit similar performance for large sample sizes, for relatively small sample sizes, the method of Pilla et al. leads to an artificial inflation of statistical power that stems from an increase in the false detection rate. This method, on the other hand, becomes particularly useful in multidimensional searches, where the Monte Carlo simulations required by Gross and Vitells are often unfeasible. We apply the methods to realistic simulations of the Fermi Large Area Telescope data, in particular the search for dark matter annihilation lines. Further, we discuss the counter-intuitive scenario where the look-elsewhere corrections are more conservative than much more computationally efficient corrections for multiple hypothesis testing. Finally, we provide general guidelines for navigating the tradeoffs between statistical and computational efficiency when selecting a statistical procedure for signal detection.

  • 19.
    Ali, Safdar
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Mahmood, Sultan
    Stockholm University, Faculty of Science, Department of Physics.
    Orban, Istvan
    Stockholm University, Faculty of Science, Department of Physics.
    Tashenov, Stanislav
    Stockholm University, Faculty of Science, Department of Physics.
    Li, Y. M.
    Wu, Z.
    Schuch, Reinhold
    Stockholm University, Faculty of Science, Department of Physics.
    Photo-recombination studies at R-EBIT with a Labview control and data = quisition system2011In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 6, p. C01016-Article in journal (Refereed)
    Abstract [en]

    Equipment at the Stockholm Refrigerated Electron Beam Ion Trap (R-EBIT) was developed for photo-recombination studies. A LabView-based event mode data acquisition and R-EBIT control system was implemented. The energies of KLL dielectronic recombination resonances in Li- to C-like argon ions were determined and compared with theoretical calculations performed using a distorted wave approximation. The theoretical and experimental peak positions for Li-, Be-, and C-like argon ions agree within the error bars. For B-like argon we observe an energy shift of 9 eV between the experimentally obtained peak position and the calculated result.

  • 20. Anderson, D.
    et al.
    Andrais, B.
    Mirzayans, R.
    Siegbahn, Albert
    Stockholm University, Faculty of Science, Department of Physics.
    Fallone, B. G.
    Warkentin, B.
    Comparison of two methods for measuring gamma-H2AX nuclear fluorescence as a marker of DNA damage in cultured human cells: applications for microbeam radiation therapy2013In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 8, p. C06008-Article in journal (Refereed)
    Abstract [en]

    Microbeam radiation therapy (MRT) delivers single fractions of very high doses of synchrotron x-rays using arrays of microbeams. In animal experiments, MRT has achieved higher tumour control and less normal tissue toxicity compared to single-fraction broad beam irradiations of much lower dose. The mechanism behind the normal tissue sparing of MRT has yet to be fully explained. An accurate method for evaluating DNA damage, such as the gamma-H2AX immunofluorescence assay, will be important for understanding the role of cellular communication in the radiobiological response of normal and cancerous cell types to MRT. We compare two methods of quantifying gamma-H2AX nuclear fluorescence for uniformly irradiated cell cultures: manual counting of gamma-H2AX foci by eye, and an automated, MATLAB-based fluorescence intensity measurement. We also demonstrate the automated analysis of cell cultures irradiated with an array of microbeams. In addition to offering a relatively high dynamic range of gamma-H2AX signal versus irradiation dose (>10 Gy), our automated method provides speed, robustness, and objectivity when examining a series of images. Our in-house analysis facilitates the automated extraction of the spatial distribution of the gamma-H2AX intensity with respect to the microbeam array - for example, the intensities in the peak (high dose area) and valley (area between two microbeams) regions. The automated analysis is particularly beneficial when processing a large number of samples, as is needed to systematically study the relationship between the numerous dosimetric and geometric parameters involved with MRT (e.g., microbeam width, microbeam spacing, microbeam array dimensions, peak dose, valley dose, and geometric arrangement of multiple arrays) and the resulting DNA damage.

  • 21. Andresen, G. B.
    et al.
    Ashkezari, M. D.
    Baquero-Ruiz, M.
    Bertsche, W.
    Bowe, P. D.
    Butler, E.
    Cesar, C. L.
    Chapman, S.
    Charlton, M.
    Deller, A.
    Eriksson, S.
    Fajans, J.
    Friesen, T.
    Fujiwara, M. C.
    Gill, D. R.
    Gutierrez, A.
    Hangst, J. S.
    Hardy, W. N.
    Hayden, M. E.
    Humphries, A. J.
    Hydomako, R.
    Jenkins, M. J.
    Jonsell, Svante
    Stockholm University, Faculty of Science, Department of Physics.
    Jorgensen, L. V.
    Kurchaninov, L.
    Madsen, N.
    McKenna, J. T. K.
    Menary, S.
    Nolan, P.
    Olchanski, K.
    Olin, A.
    Povilus, A.
    Pusa, P.
    Robicheaux, F.
    Sampson, J.
    Sarid, E.
    Seddon, D.
    el Nasr, S. Seif
    Silveira, D. M.
    So, C.
    Storey, J. W.
    Thompson, R. I.
    Thornhill, J.
    Wells, D.
    van der Werf, D. P.
    Wurtele, J. S.
    Yamazaki, Y.
    The ALPHA-detector: Module Production and Assembly2012In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 7, p. C01051-Article in journal (Refereed)
    Abstract [en]

    ALPHA is one of the experiments situated at CERN's Antiproton Decelerator (AD). A Silicon Vertex Detector (SVD) is placed to surround the ALPHA atom trap. The main purpose of the SVD is to detect and locate antiproton annihilation events by means of the emitted charged pions. The SVD system is presented with special focus given to the design, fabrication and performance of the modules.

  • 22.
    Bergeås Kuutmann, Elin
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    A Layer Correlation Technique for Pion Energy Calibration at the 2004 ATLAS Combined Beam Test2011In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 6, p. P06001-Article in journal (Refereed)
    Abstract [en]

    A new method for calibrating the hadron response of a segmented calorimeter is developed and successfully applied to beam test data. It is based on a principal component analysis of energy deposits in the calorimeter layers, exploiting longitudinal shower development information to improve the measured energy resolution. Corrections for invisible hadronic energy and energy lost in dead material in front of and between the calorimeters of the ATLAS experiment were calculated with simulated Geant4 Monte Carlo events and used to reconstruct the energy of pions impinging on the calorimeters during the 2004 Barrel Combined Beam Test at the CERN H8 area. For pion beams with energies between 20 GeV and 180 GeV, the particle energy is reconstructed within 3% and the energy resolution is improved by between 11% and 25% compared to the resolution at the electromagnetic scale.

  • 23.
    Bergeås Kuutmann, Elin
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Photon Reconstruction in the ATLAS Inner Detector and Liquid Argon Barrel Calorimeter at the 2004 Combined Test Beam2011In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 6, p. P04001-Article in journal (Refereed)
    Abstract [en]

    The reconstruction of photons in the ATLAS detector is studied with data taken during the 2004 Combined Test Beam, where a full slice of the ATLAS detector was exposed to beams of particles of known energy at the CERN SPS. The results presented show significant differences in the longitudinal development of the electromagnetic shower between converted and unconverted photons as well as in the total measured energy. The potential to use the reconstructed converted photons as a means to precisely map the material of the tracker in front of the electromagnetic calorimeter is also considered. All results obtained are compared with a detailed Monte-Carlo simulation of the test-beam setup which is based on the same simulation and reconstruction tools as those used for the ATLAS detector itself.                   

  • 24.
    Bohm, Christian
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Danninger, Matthias
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Finley, Chad
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Flis, Samuel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hulth, Per-Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Walck, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Wolf, Martin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Zoll, Marcel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Energy reconstruction methods in the IceCube neutrino telescope2014In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 9, p. P03009-Article in journal (Refereed)
    Abstract [en]

    Accurate measurement of neutrino energies is essential to many of the scientific goals of large-volume neutrino telescopes. The fundamental observable in such detectors is the Cherenkov light produced by the transit through a medium of charged particles created in neutrino interactions. The amount of light emitted is proportional to the deposited energy, which is approximately equal to the neutrino energy for v(e) and v(mu) charged-current interactions and can be used to set a lower bound on neutrino energies and to measure neutrino spectra statistically in other channels. Here we describe methods and performance of reconstructing charged-particle energies and topologies from the observed Cherenkov light yield, including techniques to measure the energies of uncontained muon tracks, achieving average uncertainties in electromagnetic-equivalent deposited energy of similar to 15% above 10 TeV.

  • 25.
    Böhlen, Till Tobias
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Ferrari, A.
    Patera, V.
    Sala, P. R.
    Describing Compton scattering and two-quanta positron annihilation based on Compton profiles: two models suited for the Monte Carlo method2012In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 7, p. P07018-Article in journal (Refereed)
    Abstract [en]

    An accurate description of the basic physics processes of Compton scattering and positron annihilation in matter requires the consideration of atomic shell structure effects and, in specific, the momentum distributions of the atomic electrons. Two algorithms which model Compton scattering and two-quanta positron annihilation at rest accounting for shell structure effects are proposed. Two-quanta positron annihilation is a physics process which is of particular importance for applications such as positron emission tomography (PET). Both models use a detailed description of the processes which incorporate consistently Doppler broadening and binding effects. This together with the relatively low level of complexity of the models makes them particularly suited to be employed by fast sampling methods for Monte Carlo particle transport. Momentum distributions of shell electrons are obtained from parametrized one-electron Compton profiles. For conduction electrons, momentum distributions are derived in the framework of a Fermi gas. The Compton scattering model uses an approach which does not employ any free parameter. In contrast, a few semi-empirical approximations are included for the description of the complex physics of electron-positron annihilation resulting in acollinear photons. Comparisons of the Compton scattering model with simpler approaches illustrate the detailed accounting for shell structure effects. A satisfactory agreement is found for comparisons of both newly-developed models with experimental data.

  • 26. Creus, W.
    et al.
    Allkofer, Y.
    Amsler, C.
    Ferella, Alfredo D.
    Stockholm University, Faculty of Science, Department of Physics.
    Rochet, J.
    Scotto-Lavina, L.
    Walter, M.
    Scintillation efficiency of liquid argon in low energy neutron-argon scattering2015In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 10, article id P08002Article in journal (Refereed)
    Abstract [en]

    Experiments searching for weak interacting massive particles with noble gases such as liquid argon require very low detection thresholds for nuclear recoils. A determination of the scintillation efficiency is crucial to quantify the response of the detector at low energy. We report the results obtained with a small liquid argon cell using a monoenergetic neutron beam produced by a deuterium-deuterium fusion source. The light yield relative to electrons was measured for six argon recoil energies between 11 and 120 keV at zero electric drift field.

  • 27.
    Eriksson, Daniel
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Muschter, Steffen
    Stockholm University, Faculty of Science, Department of Physics.
    Anderson, K.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Kavianipour, Hossein
    Stockholm University, Faculty of Science, Department of Physics.
    Oreglia, M.
    Tang, F.
    A prototype for the upgraded readout electronics of TileCal2012In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 7, article id C02006Article in journal (Refereed)
    Abstract [en]

    Upgrade plans for the ATLAS hadronic tile calorimeter (TileCal) at the LHC include full granularity readout to the 1st level trigger. R&D activities at different laboratories target different parts of the upgraded system. We are developing a possible implementation of the future readout electronics to be included in a full functional demonstrator. This must be capable of adapting to each of the three different front-end alternatives being considered. Prototypes of the two PCBs that will be in charge of digitization, control and communication have been developed. The design is redundant and uses FPGAs with fault tolerant firmware for control and protocol conversion. Communication and clock synchronization between on and offdetector electronics is implemented via high speed optical links using the GBT protocol.

  • 28.
    Eriksson, Daniel
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Muschter, Steffen
    Stockholm University, Faculty of Science, Department of Physics.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    An FPGA based backup version of the TileCal Digitizer2010In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 5, article id C11020Article in journal (Refereed)
    Abstract [en]

    The ATLAS Tile Calorimeter front end digitization and readout system comprises about 1800 digitizer boards with two TileDMU ASICs on each board. The TileDMUs are responsible for storing, derandomising and reading out digitized data from twelve ADCs. An ample number of board spares are available. However, a backup solution is desirable in the event of unexpected failure modes. The original version contains both outdated and custom made circuits that are difficult or impossible to find in sufficient numbers. We have developed a new version using inexpensive off the shelf FPGAs (Spartan 6). The FPGAs have all the necessary functionality to emulate the TileDMU and will be readily available for a considerable time. The new board is functionally compatible with the current version and to a large extent uses the same code. The design goal was to leave the digitizer design as intact as possible since it is well tested and performs well. As radiation tolerance is an issue we have implemented triple mode redundancy in the FPGA. To further improve the system we added in system programmability via TTCrx for both the FPGA and the configuration memory using one way JTAG. This provides a way to recover from radiation damage to the configuration PROM or to remotely upgrade system firmware.

  • 29.
    Muschter, Steffen
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Anderson, K.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Eriksson, Daniel
    Stockholm University, Faculty of Science, Department of Physics.
    Oreglia, M.
    Tang, F.
    Development of a readout link board for the demonstrator of the ATLAS Tile calorimeter upgrade2013In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 8, article id C03025Article in journal (Refereed)
    Abstract [en]

    A hybrid readout system is being developed for installation in one module of the ATLAS scintillating Tile Calorimeter (TileCal) during the long LHC shutdown in 2013/2014. The hybrid combines a fully functional demonstrator of the full-digital system planned for installation in 2022 with circuitry to maintain compatibility with the existing system. This is the report on a second generation prototype link and controller board connecting the on-and off-detector electronics. The main logic component within this board is a XILINX Kintex-7 FPGA connected to an 12x5 Gbps SNAP12 opto transmitter and a 4x10 Gbps QSFP+ connector, for off-detector communication. One of the latter two will be chosen for the final design.

  • 30.
    Muschter, Steffen
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Baron, S.
    Bohm, Christian
    Cachemiche, J. -P
    Soos, C.
    Erratum: Optimizing latency in Xilinx FPGA implementations of the GBT2011In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 6, article id E05001Article in journal (Other academic)
  • 31.
    Muschter, Steffen
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Baron, S.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Cachemiche, J. -P
    Soos, C.
    Optimizing latency in Xilinx FPGA implementations of the GBT2010In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 5, article id C12017Article in journal (Refereed)
    Abstract [en]

    The GigaBit Transceiver (GBT) [1] system has been developed to replace the Timing, Trigger and Control (TTC) system [2], currently used by LHC, as well as to provide data transmission between on-detector and off-detector components in future sLHC detectors. A VHDL version of the GBT-SERDES, designed for FPGAs, was released in March 2010 as a GBT-FPGA Starter Kit for future GBT users and for off-detector GBT implementation [3]. This code was optimized for resource utilization [4], as the GBT protocol is very demanding. It was not, however, optimized for latency - which will be a critical parameter when used in the trigger path. The GBT-FPGA Starter Kit firmware was first analyzed in terms of latency by looking at the separate components of the VHDL version. Once the parts which contribute most to the latency were identified and modified, two possible optimizations were chosen, resulting in a latency reduced by a factor of three. The modifications were also analyzed in terms of logic utilization. The latency optimization results were compared with measurement results from a Virtex 6 ML605 development board [5] equipped with a XC6VLX240T with speedgrade-1 and the package FF1156. Bit error rate tests were also performed to ensure an error free operation. The two final optimizations were analyzed for utilization and compared with the original code, distributed in the Starter Kit.

  • 32.
    Muschter, Steffen
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Åkerstedt, Henrik
    Stockholm University, Faculty of Science, Department of Physics.
    Anderson, K.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Oreglia, M.
    Tang, F.
    Development of a digital readout board for the ATLAS Tile Calorimeter upgrade demonstrator2014In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 9, article id C01001Article in journal (Refereed)
    Abstract [en]

    During the LHC shutdown in 2013/14, one of the ATLAS scintillating Tile Calorimeter (TileCal) on-detector modules will be replaced with a compatible hybrid demonstrator system. This is being built to fulfill all requirements for the complete upgrade of the TileCal electronics in 2022 but augmented to stay compatible with the present system. We report on the hybrid system's FPGA based communication module that is responsible for receiving and unpacking commands using a 4.8 Gbps downlink and driving a high bandwidth data uplink. The report includes key points like multi-gigabit transmission, clock distribution, programming and operation of the hardware. We also report on a firmware skeleton implementing all these key points and demonstrate how timing, trigger, control and data transmission can be achieved in the demonstrator.

  • 33.
    Plucinski, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Upgrades to the ATLAS Level-1 Calorimeter Trigger2014In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 9, p. C01023-Article in journal (Refereed)
    Abstract [en]

    In 2015 the Large Hadron Collider will run with increased center-of-mass energy and luminosity. To maintain a high efficiency in selecting interesting collisions for the physics analyses in the next data-taking period, event topology information will be added to the ATLAS Level-1 real time data path and processed by a new Topology Processor (L1Topo). To cope with the luminosity levels foreseen after the 2018 LHC upgrade, a new digital trigger path for the Liquid Argon calorimeters will provide finer granularity and depth segmentation in the electromagnetic layer to new Level-1 feature extractors (FEX) for an improved electron, photon, tau and jet selection. We present the ongoing and future calorimeter trigger upgrades to the ATLAS Level-1 trigger.

  • 34.
    Schuch, Reinhold
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Tashenov, Stanislav
    Stockholm University, Faculty of Science, Department of Physics.
    Orban, Istvan
    Stockholm University, Faculty of Science, Department of Physics.
    Hobein, Matthias
    Stockholm University, Faculty of Science, Department of Physics.
    Mahmood, Sultan
    Stockholm University, Faculty of Science, Department of Physics.
    Kamalou, O.
    Stockholm University, Faculty of Science, Department of Physics.
    Akram, Nadeem
    Stockholm University, Faculty of Science, Department of Physics.
    Safdar, Ali
    Stockholm University, Faculty of Science, Department of Physics.
    Skog, Patrik
    Stockholm University, Faculty of Science, Department of Physics.
    Solders, Andreas
    Stockholm University, Faculty of Science, Department of Physics.
    Zhang, Hongqiang
    Stockholm University, Faculty of Science, Department of Physics.
    The new Stockholm Electron Beam Ion Trap (S-EBIT)2010In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 5, p. C12018-Article in journal (Refereed)
    Abstract [en]

    A new laboratory for highly charged ions is being built up at Stockholm University. A fully refrigerated electron beam ion trap (R-EBIT, 3 T magnet, 30 keV electron energy) was installed. It was used for spectroscopic studies, ion cooling experiments, electron ion collisions, and highly-charged ion surface studies. Here we report on an upgrade of this EBIT to a ``Super EBIT'' (S-EBIT, 4 T magnet, 260 keV electron energy). The high-voltage trapping system, the ion injection as well as the extraction scheme of S-EBIT and the LabView based operational system of S-EBIT are described.

  • 35.
    Tashenov, Stanislav
    Stockholm University, Faculty of Science, Department of Physics. Helmholtz Association, Germany.
    Identification of bremsstrahlung events in gamma-ray tracking detectors2010In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 5, article id P10004Article in journal (Refereed)
    Abstract [en]

    Tracking of gamma-rays in position sensitive germanium and silicon detectors is a relatively new concept. In the energy region of a few hundred keV up to a few MeV it aims at identification of the sequence and positions of photon scattering points inside a detector. This is achieved by verifying the energy and momentum conservation laws for each Compton interaction as well as the scattering and absorption probabilities. By calculating multiple figures of merit, each favoring a specific class of events (e.g. full-energy, escape and bremsstrahlung), one can identify these events and increase the peak/total ratio of the full-energy spectrum. As an example, events where bremsstrahlung photons are produced by Compton recoiled electrons are identified. A further extension of this technique may allow identification of pair production events and extend the tracking analysis into a higher energy region of several MeV where pair production dominates.

  • 36.
    Wallängen, Veronica
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Lawrence Berkeley National Laboratory, U.S.A..
    Garcia-Sciveres, M.
    Decision feedback equalization for radiation hard data link at 5 Gbps2017In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 12, article id C01067Article in journal (Refereed)
    Abstract [en]

    The increased particle collision rate following the upgrade of the Large Hadron Collider (LHC) to an increased luminosity requires an increased readout data speed, especially for the ATLAS pixel detector, located closest to the particle interaction point. For this reason, during the Phase-II upgrade of the ATLAS experiment the output data speed of the pixel front-end chips will be increased from 160 Mbps to 5 Gbps. The increased radiation levels will require a radiation hard data transmission link to be designed to carry this data from the pixel front-end to the off-detector system where it will undergo optical conversion. We propose a receiver utilizing the concept of Decision Feedback Equalization (DFE) to be used in this link, where the number of filter taps can be determined from simulations using S-parameter data from measurements of various customized cable prototypes under characterization as candidates to function as transmission medium between the on-chip data driver and the receiver of the link. A dedicated framework has been set up in Matlab to analyze the S-parameter characteristics for the various cable prototypes and investigate the possibilities for signal recovery and maintained signal integrity using DFE, as well as pre-emphasis and different encoding schemes. The simulation results indicate that DFE could be an excellent choice for expanding the system bandwidth to reach required data speeds with minimal signal distortion.

  • 37.
    Åkerstedt, Henrik
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Muschter, Steffen
    Stockholm University, Faculty of Science, Department of Physics.
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Valdés, Eduardo
    Stockholm University, Faculty of Science, Department of Physics.
    A radiation tolerant Data link board for the ATLAS Tile Cal upgrade2016In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 11, article id C01074Article in journal (Refereed)
    Abstract [en]

    This paper describes the latest, full-functionality revision of the high-speed data link board developed for the Phase-2 upgrade of ATLAS hadronic Tile Calorimeter. The link board design is highly redundant, with digital functionality implemented in two Xilinx Kintex-7 FPGAs, and two Molex QSFP+ electro-optic modules with uplinks run at 10 Gbps. The FPGAs are remotely configured through two radiation-hard CERN GBTx deserialisers (GBTx), which also provide the LHC-synchronous system clock. The redundant design eliminates virtually all single-point error modes, and a combination of triple-mode redundancy (TMR), internal and external scrubbing will provide adequate protection against radiation-induced errors. The small portion of the FPGA design that cannot be protected by TMR will be the dominant source of radiation-induced errors, even if that area is small.

  • 38.
    Åsman, Barbro
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Achenbach, R.
    Allbrooke, B. M. M.
    Anders, G.
    Andrei, V.
    Büscher, V.
    Bansil, H. S.
    Barnett, B. M.
    Bauss, B.
    Bendtz, Katarina
    Stockholm University, Faculty of Science, Department of Physics.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Bracinik, J.
    Brawn, I. P.
    Brock, R.
    Buttinger, W.
    Caputo, R.
    Caughron, S.
    Cerrito, L.
    Charlton, D. G.
    Childers, J. T.
    Curtis, C. J.
    Daniells, A. C.
    Davis, A. O.
    Davygora, Y.
    Dorn, M.
    Eckweiler, S.
    Edmunds, D.
    Edwards, J. P.
    Eisenhandler, E.
    Ellis, K.
    Ermoline, Y.
    Föhlisch, F.
    Faulkner, P. J. W.
    Fedorko, W.
    Fleckner, J.
    French, S. T.
    Gee, C. N. P.
    Gillman, A. R.
    Goeringer, C.
    Hülsing, T.
    Hadley, D. R.
    Hanke, P.
    Hauser, R.
    Heim, S.
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics.
    Hickling, R. S.
    Hidvégi, A.
    Hillier, S. J.
    Hofmann, J. I.
    Hristova, I.
    Ji, W.
    Johansen, Marianne
    Stockholm University, Faculty of Science, Department of Physics.
    Keller, M.
    Khomich, A.
    Kluge, E. -E
    Koll, J.
    Laier, H.
    Landon, M. P. J.
    Lang, V. S.
    Laurens, P.
    Lepold, F.
    Lilley, J. N.
    Linnemann, J. T.
    Müller, F.
    Müller, T.
    Mahboubi, K.
    Martin, T. A.
    Mass, A.
    Meier, K.
    Meyer, C.
    Middleton, R. P.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Moritz, S.
    Morris, J. D.
    Mudd, R. D.
    Narayan, R.
    Nedden, M. Zur
    Neusiedl, A.
    Newman, P. R.
    Nikiforov, A.
    Ohm, Christian C.
    CERN.
    Perera, V. J. O.
    Pfeiffer, U.
    Plucinski, Pawel
    Stockholm University, Faculty of Science, Department of Physics.
    Poddar, S.
    Prieur, D. P. F.
    Qian, W.
    Rieck, P.
    Rizvi, E.
    Sankey, D. P. C.
    Schäfer, U.
    Scharf, V.
    Schmitt, K.
    Schröder, C.
    Schultz-Coulon, H. -C
    Schumacher, C.
    Schwienhorst, R.
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Simioni, E.
    Snidero, G.
    Staley, R. J.
    Stamen, R.
    Stock, P.
    Stockton, M. C.
    Tan, C. L. A.
    Tapprogge, S.
    Thomas, J. P.
    Thompson, P. D.
    Thomson, M.
    True, P.
    Watkins, P. M.
    Watson, A. T.
    Watson, M. F.
    Wessels, M.
    Weber, P.
    Wiglesworthi, C.
    Williams, S. L.
    The ATLAS Level-1 Calorimeter Trigger: PreProcessor implementation and performance2012In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 7, article id P12008Article in journal (Refereed)
    Abstract [en]

    The PreProcessor system of the ATLAS Level-1 Calorimeter Trigger (L1Calo) receives about 7200 analogue signals from the electromagnetic and hadronic components of the calorimetric detector system. Lateral division results in cells which are pre-summed to so-called Trigger Towers of size 0.1 x 0.1 along azimuth (phi) and pseudorapidity (eta). The received calorimeter signals represent deposits of transverse energy. The system consists of 124 individual PreProcessor modules that digitise the input signals for each LHC collision, and provide energy and timing information to the digital processors of the L1Calo system, which identify physics objects forming much of the basis for the full ATLAS first level trigger decision. This paper describes the architecture of the PreProcessor, its hardware realisation, functionality, and performance.

  • 39.
    Åsman, Barbro
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bendtz, Katarina
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Eriksson, Daniel
    Stockholm University, Faculty of Science, Department of Physics.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Johansen, Marianne
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Johansson, K. Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Khandanyan, Hovhannes
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Kim, Hyeon Jin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Klimek, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Johan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Olle
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ohm, Christian C.
    CERN.
    Papadelis, Aras
    Stockholm University, Faculty of Science, Department of Physics.
    Sellden, Björn
    Stockholm University, Faculty of Science, Department of Physics.
    Silverstein, Samuel
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Strandberg, Sara
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Tylmad, Maja
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Yang, Zhaoyu
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Characterisation and mitigation of beam-induced backgrounds observed in the ATLAS detector during the 2011 proton-proton run2013In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 8, p. P07004-Article in journal (Refereed)
    Abstract [en]

    This paper presents a summary of beam-induced backgrounds observed in the ATLAS detector and discusses methods to tag and remove background contaminated events in data. Trigger-rate based monitoring of beam-related backgrounds is presented. The correlations of backgrounds with machine conditions, such as residual pressure in the beam-pipe, are discussed. Results from dedicated beam-background simulations are shown, and their qualitative agreement with data is evaluated. Data taken during the passage of unpaired, i.e. non-colliding, proton bunches is used to obtain background-enriched data samples. These are used to identify characteristic features of beam-induced backgrounds, which then are exploited to develop dedicated background tagging tools. These tools, based on observables in the Pixel detector, the muon spectrometer and the calorimeters, are described in detail and their efficiencies are evaluated. Finally an example of an application of these techniques to a monojet analysis is given, which demonstrates the importance of such event cleaning techniques for some new physics searches.

  • 40.
    Åsman, Barbro
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bendtz, Katarina
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Johansen, Marianne
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lundberg, Johan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ohm, Christian
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    The ATLAS Data Acquisition and High Level Trigger system2016In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 11, article id P06008Article in journal (Refereed)
    Abstract [en]

    This paper describes the data acquisition and high level trigger system of the ATLAS experiment at the Large Hadron Collider at CERN, as deployed during Run 1. Data flow as well as control, configuration and monitoring aspects are addressed. An overview of the functionality of the system and of its performance is presented and design choices are discussed.

  • 41.
    Åsman, Barbro
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Eriksson, Daniel
    Stockholm University, Faculty of Science, Department of Physics.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hidvégi, Attila
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Johansen, Marianne
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Johansson, K. Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lesser, J.
    Stockholm University, Faculty of Science, Department of Physics.
    Lundberg, Johan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Nordkvist, Björn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ohm, Christian C.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Papadelis, Aras
    Stockholm University, Faculty of Science, Department of Physics.
    Ramstedt, M.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Sellden, Björn
    Stockholm University, Faculty of Science, Department of Physics.
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Strandberg, Sara
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Tylmad, Maja
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Yang, Zhaoyu
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    A study of the material in the ATLAS inner detector using secondary hadronic interactions2012In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 7, p. P01013-Article in journal (Refereed)
    Abstract [en]

    The ATLAS inner detector is used to reconstruct secondary vertices due to hadronic interactions of primary collision products, so probing the location and amount of material in the inner region of ATLAS. Data collected in 7 TeV pp collisions at the LHC, with a minimum bias trigger, are used for comparisons with simulated events. The reconstructed secondary vertices have spatial resolutions ranging from similar to 200 mu m to 1 mm. The overall material description in the simulation is validated to within an experimental uncertainty of about 7%. This will lead to a better understanding of the reconstruction of various objects such as tracks, leptons, jets, and missing transverse momentum.

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