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  • 1.
    Adiels, L.
    et al.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Alberis, G.
    Dept. of Nuclear Physics, University of Tessaloniki.
    Backenstoss, G.
    Institute for Physics, University of Basle.
    Blüm, P.
    Kernforschungszentrum, Universität Karlsruche.
    Bergström, I.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Fransson, K.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Guigas, R.
    Kernforschungszentrum, Universität Karlsruche.
    Hasinoff, M.
    Institute for Physics, University of Basle.
    Koch, H.
    Kernforschungszentrum, Universität Karlsruche.
    Kerek, A.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Meyer, M.
    Kernforschungszentrum, Universität Karlsruche.
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Poth, H.
    Kernforschungszentrum, Universität Karlsruche.
    Raich, U.
    Kernforschungszentrum, Universität Karlsruche.
    Richter, B.
    Kernforschungszentrum, Universität Karlsruche.
    Repond, J.
    Institute for Physics, University of Basle.
    Suffert, M.
    Centre de recherches nucléaries and Université Louis Pasteur, Strabourg.
    Tauscher, L.
    Institute for Physics, University of Basle.
    Tröster, D.
    Institute for Physics, University of Basle.
    Zioutas, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Pi0 and eta spectra from proton-antiproton annihilations at rest1984In: Zeitschrift für Physik. C, Particles and fields, ISSN 0170-9739, Vol. 21, no 4, p. 315-319Article in journal (Refereed)
    Abstract [en]

    The low-energy part of the π0 spectrum associated with Mathematical expression annihilation at rest was measured in order to search for bound baryonium-like states. The upper limit for reaching such states via the emission of monochromatic π0’s was found to be 8% per annihilation in the mass region of 1650 MeV. The low-energy part of the η spectrum from Mathematical expression annihilations at rest was also observed.

  • 2.
    Adiels, L
    et al.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Antonelli, A
    Backenstoss, G.
    Institute for Physics, University of Basle.
    Beltrami, I
    Bergström, I.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Bloch, P
    Burgun, G
    DPhPe, CENSaclay.
    Carius, S.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Chardalas, M
    Charalambous, S.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Dedoussis, S
    Derré, J
    Dousse, J. C.
    University of Fribourg.
    Dris, M
    Faure, J L
    Fetscher, W
    Fry, J R
    Filokyprou, G
    Gabathuler, Erwin
    Gamet, R
    Garreta, D
    Geralis, J
    Gerber, H J
    Guyot, C
    Hatzifotiadou, D.
    Hayman, P
    Hugi, M
    Institute for Physics, University of Basle.
    Kern, J
    Kerek, A.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Kesseler, G
    Kochowski, Claude
    Kokinias, P
    Kostarakis, P
    Kuzminski, J
    Lefas, C
    Lindblad, T
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Mall, U
    Marel, Gérard
    Mason, P
    Milshtein, A I
    Nakada, Tatsuya
    Nilsson, A
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Papadopoulos, I M
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Pauli, E
    Rickenbach, R
    Schaller, L A
    Schopper, A
    Tauscher, L.
    Institute for Physics, University of Basle.
    Tröster, D.
    Institute for Physics, University of Basle.
    Tzamouranis, Yu
    Watson, E. J.
    CERN.
    Zevgolatakos, S
    Study of CP violation in a tagged neutral kaon beam.1986In: Topical European Meeting on the Quark Structure of Matter in the Rhine Valley, 1986Conference paper (Other academic)
  • 3.
    Adiels, L
    et al.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Backenstoss, G.
    Institute for Physics, University of Basle.
    Bergström, I.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Carius, S.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Charalambous, S.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Cooper, M. D.
    Institute for Physics, University of Basle.
    Findeisen, C.
    Institute for Physics, University of Basle.
    Fransson, K.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Hatzifotiadou, D.
    Kerek, A.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Papastefanou, C
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Repond, J.
    Institute for Physics, University of Basle.
    Tauscher, L.
    Institute for Physics, University of Basle.
    Tröster, D.
    Institute for Physics, University of Basle.
    Williams, M. C. S.
    Institute for Physics, University of Basle.
    Zioutas, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Investigations on baryonium and other rare p‾p annihilation modes using high resolution π0 spectrometers (PS 182)1985In: Antiproton 1984: proceedings of the VII European Symposium on Antiproton Interactions held in Durham, 9-13 July 1984 / [ed] M.R. Pennington, Bristol: Techno House , 1985, Vol. 73Conference paper (Other academic)
  • 4.
    Adiels, L
    et al.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Backenstoss, G.
    Institute for Physics, University of Basle.
    Bergström, I.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Carius, S.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Charalambous, S.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Cooper, M. D.
    Institute for Physics, University of Basle.
    Findeisen, C.
    Institute for Physics, University of Basle.
    Hatzifotiadou, D.
    Hugi, M
    Institute for Physics, University of Basle.
    Kerek, A.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Meyer, M.
    Kernforschungszentrum, Universität Karlsruche.
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Papastefanou, C
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Repond, J.
    Institute for Physics, University of Basle.
    Tauscher, L.
    Institute for Physics, University of Basle.
    Tröster, D.
    Institute for Physics, University of Basle.
    Williams, M. C. S.
    Institute for Physics, University of Basle.
    Zioutas, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Some results of experiment PS182 at LEAR1986In: Antiproton 86  : VIII European symposium on nucleon-antinucleon interactions, 1-5 September 1986, Singspore: World Scientific Publishing , 1986, p. 199-204Conference paper (Other academic)
  • 5.
    Adiels, L.
    et al.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Backenstoss, G.
    Institute for Physics, University of Basle.
    Bergström, I.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Carius, S.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Charalambous, S.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Cooper, M. D.
    Institute for Physics, University of Basle.
    Findeisen, C.
    Institute for Physics, University of Basle.
    Hatzifotiadou, D.
    Hugi, M.
    Institute for Physics, University of Basle.
    Kerek, A.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Meyer, M.
    Kernforschungszentrum, Universität Karlsruche.
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Repond, J.
    Institute for Physics, University of Basle.
    Tauscher, L.
    Institute for Physics, University of Basle.
    Tröster, D.
    Institute for Physics, University of Basle.
    Williams, M. C. S.
    Institute for Physics, University of Basle.
    Zioutas, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Experimental determination of the branching ratios proton-antiproton -> 2pi0, pi0γ and γγ at rest1987In: Zeitschrift für Physik C Particles and Fields, ISSN 0170-9739, Vol. 35, no 1, p. 15-19Article in journal (Refereed)
    Abstract [en]

    The branching ratios of Mathematical expression annihilations into the neutral final states 2π0, π0γ, and 2γ are measured by stopping antiprotons in liquid hydrogen. They are Mathematical expression, Mathematical expression, and Bγγ<1.7×10-6 (95% c.l.). © 1987 Springer-Verlag.

  • 6.
    Adiels, L
    et al.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Backenstoss, G.
    Institute for Physics, University of Basle.
    Bergström, I.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Carius, S.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Charalambous, S.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Cooper, M. D.
    Institute for Physics, University of Basle.
    Findeisen, C.
    Institute for Physics, University of Basle.
    Hatzifotiadou, D.
    Kerek, A.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Kuzminski, J
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Repond, J.
    Institute for Physics, University of Basle.
    Tauscher, L.
    Institute for Physics, University of Basle.
    Tröster, D.
    Institute for Physics, University of Basle.
    Williams, M. C. S.
    Institute for Physics, University of Basle.
    Zioutas, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    π0 and η spectroscopy at LEAR1985In: Physics with antiprotons at LEAR in the ACOL era: proceedings of the Third LEAR Workshop, Tignes, Savoie, France, January 19-26, 1985 / [ed] U. Gastaldi et al, Gif sur Yvette: Editions Frontières , 1985, p. 359-360Conference paper (Other academic)
  • 7.
    Adiels, L
    et al.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Backenstoss, G.
    Institute for Physics, University of Basle.
    Bergström, I.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Carius, S.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Charalambous, S.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Cooper, M. D.
    Institute for Physics, University of Basle.
    Findeisen, C.
    Institute for Physics, University of Basle.
    Hatzifotiadou, D.
    Kerek, A.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Papastefanou, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Repond, J.
    Institute for Physics, University of Basle.
    Tauscher, L.
    Institute for Physics, University of Basle.
    Tröster, D.
    Institute for Physics, University of Basle.
    Williams, M. C. S.
    Institute for Physics, University of Basle.
    Zioutas, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Investigations on baryonium and other rare ptoton-antiproton annihilation modes using pi0 and eta spectroscopy1986In: Proceedings of the 2nd Hellenic School on Elementary Particle Physics, Corfu, Greece, 1-20 September, 1985 / [ed] E. N. Argyres, G. Zoupanos, Singapore: World Scientific , 1986, p. 51-60Conference paper (Other academic)
  • 8.
    Adiels, L.
    et al.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Backenstoss, G.
    Institute for Physics, University of Basle.
    Bergström, I.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Carius, S.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Charalambous, S.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Cooper, M. D.
    Institute for Physics, University of Basle.
    Findeisen, C.
    Institute for Physics, University of Basle.
    Hatzifotiadou, D.
    Kerek, A.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Repond, J.
    Institute for Physics, University of Basle.
    Tauscher, L.
    Institute for Physics, University of Basle.
    Tröster, D.
    Institute for Physics, University of Basle.
    Williams, M. C. S.
    Institute for Physics, University of Basle.
    Zioutas, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Search for narrow signals in the [gamma]-spectrum from [Proton-antiproton] annihilation at rest1986In: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 182, no 3-4, p. 405-408Article in journal (Refereed)
    Abstract [en]

    The [gamma]-spectrum originating from pp[combining macron] annihilations at rest in liquid hydrogen was measured with two BGO spectrometers. A total of 24 ï¿œ 106[gamma]’s were accumulated. No narrow peaks indicating exotic states such as baryonium were observed. The upper limit for the branching ratio with 1040 [less-than-or-equals, slant] mx [less-than-or-equals, slant] 1770 MeV/c2 and with [lambda]x [less-than-or-equals, slant] 25 MeV/c2 is less than 10-3 with more than 99.96% confidence.

  • 9.
    Adiels, L.
    et al.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Backenstoss, G.
    Institute for Physics, University of Basle.
    Blüm, P.
    Kernforschungszentrum, Universität Karlsruche.
    Bergström, I.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Fransson, K.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Guigas, R.
    Kernforschungszentrum, Universität Karlsruche.
    Koch, H.
    Kernforschungszentrum, Universität Karlsruche.
    Kerek, A.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Meyer, M.
    Kernforschungszentrum, Universität Karlsruche.
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Poth, H.
    Kernforschungszentrum, Universität Karlsruche.
    Raich, U.
    Kernforschungszentrum, Universität Karlsruche.
    Richter, B.
    Kernforschungszentrum, Universität Karlsruche.
    Repond, J.
    Institute for Physics, University of Basle.
    Suffert, M.
    Centre de recherches nucléaries and Université Louis Pasteur, Strabourg.
    Tauscher, L.
    Institute for Physics, University of Basle.
    Tröster, D.
    Institute for Physics, University of Basle.
    Zioutas, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Search for narrow exotic states in annihilations on 4He1984In: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 138, no 1-3, p. 235-240Article in journal (Refereed)
    Abstract [en]

    After having found evidence for narrow exotic states in p annihilation, the production of such states on a nuclear target was studied with similar techniques. The γ spectrum associated with annihilation on 4He at rest was measured. The spectrum shows two peaks, at energies of 161.9 and 203.0 MeV, corresponding to intermediate narrow states of masses which seem to be related to states found in p annihilations. The confidence is better than 4 σ.

  • 10.
    Adiels, Lars
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Search for rare neutral two-body channels in the pp annihilation at rest: performed by measurments of high energy γ-rays using a modular NaI(Tl)-spectrometer1986Doctoral thesis, comprehensive summary (Other academic)
  • 11.
    Adiels, Lars
    et al.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Backenstoss, G.
    Institute for Physics, University of Basle.
    Bardin, G
    Bergström, I.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Bloch, P.
    CERN.
    Burgun, G
    DPhPe, CENSaclay.
    Carius, S.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Chardalas, M.
    University of Thessaloniki,.
    Charalambous, S.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Dedoussis, S.
    University of Thessaloniki.
    Derre, J.
    DPhPe, CENSaclay.
    Dousse, J. C.
    University of Fribourg.
    Dris, M
    Duclos, J
    Faure, J L
    Fetscher, W
    Fry, J R
    Findeisen, C.
    Institute for Physics, University of Basle.
    Filokyprou, G
    Gabathuler, Erwin
    University of Liverpool,.
    Gamet, R
    Gerber, H J
    Guyot, C
    Hatzifotiadou, D.
    Hayman, P
    Huet, M
    Kern, J
    Kerek, A
    Kochowski, Claude
    Kokinias, P
    Kuzminski, J
    Lefas, C
    Lindblad, T
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Mall, U
    Marel, Gérard
    Mason, P
    Milshtein, A I
    Nakada, Tatsuya
    Nilsson, A
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Papadopoulos, I M
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Pauli, E
    Schaller, L A
    Tauscher, L.
    Institute for Physics, University of Basle.
    Tröster, D.
    Institute for Physics, University of Basle.
    Ungricht, E
    Williams, M. C. S.
    Institute for Physics, University of Basle.
    Zevgolatakos, S
    Test of CP violation with K0 and K‾0 at LEAR1985In: Physics with antiprotons at LEAR in the ACOL era: proceedings of the Third LEAR Workshop, Tignes, Savoie, France, January 19-26, 1985 / [ed] Ugo Gastaldi et al, Gif sur Yvette: Editions Frontières , 1985, p. 467-482Conference paper (Other academic)
  • 12.
    Adiels, Lars
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Backenstoss, G.
    Institute for Physics, University of Basle.
    Bergström, I.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Carius, S.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Charalambous, S.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Cooper, M. D.
    Institute for Physics, University of Basle.
    Findeisen, C.
    Institute for Physics, University of Basle.
    Hatzifotiadou, D.
    Hugi, M.
    Kerek, A.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Meyer, M.
    Kernforschungszentrum, Universität Karlsruche.
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Repond, J.
    Institute for Physics, University of Basle.
    Tauscher, L.
    Institute for Physics, University of Basle.
    Troester, D.
    Institute for Physics, University of Basle.
    Williams, M. C. S.
    Institute for Physics, University of Basle.
    Zioutas, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Experimental study of the inclusive η-spectrum from proton-antiproton annihilations at rest in liquid hydrogen1989In: Zeitschrift für Physik C Particles and Fields, ISSN 0170-9739, E-ISSN 1431-5858, Vol. 42, p. 49-58Article in journal (Refereed)
    Abstract [en]

    The inclusive η-momentum spectrum from Mathematical expression annihilations at rest in liquid hydrogen was measured at LEAR. Branching ratios were obtained for Mathematical expression, and ηη(8.1±3.1)×10-5. An upper limit for Mathematical expression of 1.8×10-4 at 95% CL was found. The ratio of the branching ratios is BR(ηρvariant)/BR(ηω)=0.51-0.06+0.20. For the ratio of branching ratios into two pseudoscalar mesons, we have BR(ηπ0)/BR(π0π0)=0.65±0.14, BR(ηη)/BR(π0π0), BR(ηη′)/BR(π0π0) at 95% CL, and BR(ηη)/BR(ηπ0). © 1989 Springer-Verlag.

  • 13.
    Adiels, Lars
    et al.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Backenstoss, G.
    Institute for Physics, University of Basle.
    Bergström, I.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Carius, S.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Charalambous, S.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Cooper, M. D.
    Institute for Physics, University of Basle.
    Findeisen, C.
    Institute for Physics, University of Basle.
    Hatzifotiadou, D.
    Kerek, A.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Papastefanou, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Repond, J.
    Institute for Physics, University of Basle.
    Tauscher, L.
    Institute for Physics, University of Basle.
    Troester, D.
    Institute for Physics, University of Basle.
    Williams, M. C. S.
    Institute for Physics, University of Basle.
    Zioutas, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    A π0 and η spectrometer of lead glass and BGO for momenta up to 1 GeV/c1986In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 244, no 3, p. 380-390Article in journal (Refereed)
    Abstract [en]

    A spectrometer consisting of two sets of bismuth germanium oxide (BGO) crystals and a lead-glass array has been used to measure the [pi]0 and [eta] momentum spectra produced from proton-antiproton annihilations at rest. We describe the test of the BGO sets in electron beams of energies from 50 to 450 MeV. We discuss the method of construction and calibration of the lead-glass array, as well as procedures to extract the energy and position resolutions for detected photons. A momentum resolution ([sigma]) for [pi]0’s and [eta]’s of 4% and 3%, respectively has been achieved at momenta below 1 GeV/c.

  • 14. Andersson, Pontus
    et al.
    Fritioff, Karin
    Sandström, Joakim
    Collins, Gerard
    Hanstorp, Dag
    Ellmann, Anna
    Stockholm University, Faculty of Science, Department of Physics.
    Schef, Peter
    Stockholm University, Faculty of Science, Department of Physics.
    Lundin, Peter
    Stockholm University, Faculty of Science, Department of Physics.
    Mannervik, Sven
    Stockholm University, Faculty of Science, Department of Physics.
    Royen, Peder
    Stockholm University, Faculty of Science, Department of Physics.
    Froese Fischer, Charlotte
    Österdahl, Fabian
    Rostohar, Danijela
    Stockholm University, Faculty of Science, Department of Physics.
    Pegg, David J
    Dan Gibson, N
    Danared, Håkan
    The Manne Siegbahn Laboratory (MSL).
    Källberg, Anders
    The Manne Siegbahn Laboratory (MSL).
    Radiative lifetimes of metastable states of negative ions2006In: Physical Review A, Vol. 73, p. 032705-Article in journal (Refereed)
  • 15.
    Andreassen, Björn
    et al.
    Stockholm University, Karolinska Intstitute.
    Svensson, Roger
    Holmberg, Rickard
    Danared, Håkan
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Brahme, Anders
    Karolinska Institutet, Medical Radiation Physics.
    Development of an efficient scanning and purging magnet system for IMRT with narrow high energy photon beams2009In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 612, no 1, p. 201-208Article in journal (Refereed)
    Abstract [en]

    Due to the clinical advantages of Intensity Modulated Radiation Therapy (IMRT) high flexibility and accuracy in intensity modulated dose delivery is desirable to really maximize treatment outcome. Although it is possible to deliver IMRT by using broad beams in combination with dynamic multileaf collimation the process is rather time consuming and inefficient. By using narrow scanned high energy photon beams the treatment outcome can be improved, the treatment time reduced and accurate 3D in vivo dose delivery monitoring is possible by PET-CT based dose delivery imaging of photo nuclear reactions in human tissues. Narrow photon beams can be produced by directing a low emittance high energy electron beam on a thin target, and then cleaning the therapeutic photon beam from transmitted high energy electrons, and photon generated charged leptons, with a dedicated purging magnet placed directly downstream of the target. To have an effective scanning and purging magnet system the purging magnet should be placed immediately after the bremsstrahlung target to deflect the transmitted electrons to an efficient electron stopper. In the static electron stopper the electrons should be safely collected independent of the desired direction of the therapeutic scanned photon beam. The SID (Source to Isocentre Distance) should preferably be short while retaining the ability to scan over a large area on the patient and consequently there are severe requirements both on the strength and the geometry of the scanning and purging magnets. In the present study an efficient magnet configuration with a purging and scanning magnet assembly is developed for electron energies in the 50-75 MeV range and a SID of 75 cm. For a bremsstrahlung target of 3mm Be these electron energies produce a photon beam of 25-17 mm FWHM (Full Width Half Maximum) at a SID of 75 cm. The magnet system was examined both in terms of the efficiency in scanning the narrow bremsstrahlung beam and the deflection of transmitted and photon generated electrons. The simulations show that its is possible to have a scan area on the patient of up to 43 x 40 cm2 for an incident electron energy of 50 MeV and 28 x 40 cm2 at 75 MeV, while at the same time adequately deflecting the transmitted electron beam.

  • 16.
    Backenstoss, G.
    et al.
    Institute for Physics, University of Basle.
    Hasinoff, M.
    Institute for Physics, University of Basle.
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Repond, J.
    Institute for Physics, University of Basle.
    Tauscher, L.
    Institute for Physics, University of Basle.
    Trï¿œster, D.
    Institute for Physics, University of Basle.
    Adiels, Lars
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Bergström, Ingmar
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Fransson, Kjell
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Kerek, A.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Guigas, R.
    Kernforschungszentrum, Universität Karlsruche.
    Koch, H.
    Kernforschungszentrum, Universität Karlsruche.
    Poth, H.
    Kernforschungszentrum, Universität Karlsruche.
    Raich, U.
    Kernforschungszentrum, Universität Karlsruche.
    Richter, B.
    Kernforschungszentrum, Universität Karlsruche.
    Suffert, M.
    Centre de recherches nucléaries and Université Louis Pasteur, Strabourg.
    Zioutas, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    First Observation of the proton-antiproton Annihilation Channels pi0ω, pi0$η and pi0γ1983In: Helvetica Physica Acta, ISSN 0018-0238, Vol. 56Article in journal (Refereed)
  • 17.
    Backenstoss, G.
    et al.
    Institute for Physics, University of Basle.
    Hasinoff, M.
    Institute for Physics, University of Basle.
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Repond, J.
    Institute for Physics, University of Basle.
    Tauscher, L.
    Institute for Physics, University of Basle.
    Tröster, D.
    Institute for Physics, University of Basle.
    Blüm, P.
    Kernforschungszentrum, Universität Karlsruche.
    Guigas, R.
    Kernforschungszentrum, Universität Karlsruche.
    Koch, H.
    Kernforschungszentrum, Universität Karlsruche.
    Meyer, M.
    Kernforschungszentrum, Universität Karlsruche.
    Poth, H.
    Kernforschungszentrum, Universität Karlsruche.
    Raich, U.
    Kernforschungszentrum, Universität Karlsruche.
    Richter, B.
    Kernforschungszentrum, Universität Karlsruche.
    Adiels, L.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Bergström, I.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Fransson, K.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Kerek, A.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Suffert, M.
    Centre de recherches nucléaries and Université Louis Pasteur, Strabourg.
    Zioutas, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Proton-antiproton annihilations at rest into π0ω, π0η, π0γ, π0π0, and π0η’1983In: Nuclear Physics B, ISSN 0550-3213, E-ISSN 1873-1562, Vol. 228, no 3, p. 424-438Article in journal (Refereed)
  • 18.
    Bee, C. P.
    et al.
    Liverpool University.
    Heyes, G.
    Liverpool University,.
    Sacks, L.
    Liverpool University,.
    Adiels, L
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Tröster, D.
    Institute for Physics, University of Basle.
    Watson, E. J.
    CERN.
    Wendler, H
    The CP-LEAR data acquisition system1986In: Proceedings: VMEbus in physics conference, CERN, Geneva, Switzerland, 7th and 8th October 1985, Geneva: CERN , 1986, p. 179-184Conference paper (Other academic)
  • 19. Bergström, I
    et al.
    Björkhage, Mikael
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Blaum, K
    Bluhrne, H
    Fritioff, Tomas
    Stockholm University, Faculty of Science, Department of Physics.
    Nagy, Szilard
    Stockholm University, Faculty of Science, Department of Physics.
    Schuch, Reinhold
    Stockholm University, Faculty of Science, Department of Physics.
    High-precision Mass Measurements of Hydrogen-Like 24Mg11+ and 26Mg11+ ions in a Pening Trap2002In: European Physical Journal D: Atomic, Molecular and Optical Physics, ISSN 1434-6060, E-ISSN 1434-6079, Vol. 22, no 1, p. 41-45Article in journal (Refereed)
    Abstract [en]

    For the determination of the bound-electron g factor in hydrogen-like heavy ions the mass of the ion is needed at a relative uncertainty of at least 1 ppb. With the SMILETRAP Penning trap mass spectrometer at the Manne Siegbahn Laboratory in Stockholm several mass measurements of ions with even-even nuclei at this level of precision have been performed so far, exploiting the fact that the mass precision increases linearly with the ion charge. Measurements of masses of the hydrogen-like ions of the two Mg-isotopes 24Mg and 26Mg are reported. The masses of the hydrogen-like ions are 23.979011054(14) u and 25.976562354(34) u, corresponding to the atomic masses 23.985041690(14) u and 25.982592986(34) u, respectively. The possibility to use these two isotopes for the first observation of an isotope effect in the bound-electron g factor in hydrogen-like heavy ions is discussed.

  • 20.
    Blüm, P.
    et al.
    Kernforschungszentrum, Universität Karlsruche.
    Guigas, R.
    Kernforschungszentrum, Universität Karlsruche.
    Koch, H.
    Kernforschungszentrum, Universität Karlsruche.
    Meyer, M.
    Kernforschungszentrum, Universität Karlsruche.
    Poth, H.
    Kernforschungszentrum, Universität Karlsruche.
    Raich, U.
    Kernforschungszentrum, Universität Karlsruche.
    Richter, B.
    Kernforschungszentrum, Universität Karlsruche.
    Backenstoss, G.
    Institute for Physics, University of Basle.
    Hasinoff, M.
    Institute for Physics, University of Basle.
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Repond, J.
    Institute for Physics, University of Basle.
    Tauscher, L.
    Institute for Physics, University of Basle.
    Tröster, D.
    Institute for Physics, University of Basle.
    Adiels, L.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Bergström, I.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Fransson, K.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Kerek, A.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Suffert, M.
    Centre de recherches nucléaries and Université Louis Pasteur, Strabourg.
    Zioutas, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    A modular NaI(Tl) detector for 20-1000 MeV photons1983In: Nuclear Instruments and Methods in Physics Research, ISSN 0167-5087, Vol. 213, no 2-3, p. 251-259Article in journal (Refereed)
    Abstract [en]

    A detector consisting of 54 NaI (Tl) modules is described. The detector has been optimized for the detection of 20-1000 MeV photons. An energy resolution (fwhm) of 5.5% at 130 MeV could be attained, and the stability has been better than 1% over several months.

  • 21.
    Danared, Håkan
    et al.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Källberg, Anders
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Simonsson, Ansgar
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Studies of Cooling and Deceleration at CRYRING for FAIR2007In: COOL 2007, 2007Conference paper (Other academic)
  • 22.
    Danared, Håkan
    et al.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Rubensson, J.-E
    Tegnér, P.-E
    Department of Physics.
    FAIR och XFEL, Två nya europeiska acceleratoranläggningar2006In: Fysikaktuellt, Vol. 2, p. 5-Article in journal (Refereed)
  • 23.
    Danielsson, Mathias
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Hamberg, Mathias
    Stockholm University, Faculty of Science, Department of Physics.
    Simonsson, Ansgar
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Paál, Andreas
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Larsson, Mats
    Stockholm University, Faculty of Science, Department of Physics.
    Geppert, Wolf
    Stockholm University, Faculty of Science, Department of Physics.
    Zhaunerchyk, Vitaly
    Stockholm University, Faculty of Science, Department of Physics.
    Ehlerding, Anneli
    Stockholm University, Faculty of Science, Department of Physics.
    Kaminska, Magdalena
    Stockholm University, Faculty of Science, Department of Physics.
    Hellberg, Fredrik
    Stockholm University, Faculty of Science, Department of Physics.
    Thomas, Richard
    Stockholm University, Faculty of Science, Department of Physics.
    Österdal, Fabian
    af Ugglas, Magnus
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Källberg, Anders
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    The cross-section and branching fractions for dissociative recombination of the diacetylene cation C4D2+2008In: International Journal of Mass Spectrometry, ISSN 1387-3806, E-ISSN 1873-2798, Vol. 273, no 3, p. 111-116Article in journal (Refereed)
    Abstract [en]

    In this paper we report the results of a study on the dissociative recombination (DR) of the diacetylene cation, C4D2+, which has been carried out at the ion storage ring CRYRING in Stockholm, Sweden. The energy-dependent absolute DR cross-section as well as the branching fractions at 0 eV collision energy were measured. The DR cross-section was best fitted using the expression σ(E) = (7.5 ± 1.5) × 10−16 × E−(1.29±0.03) cm2 over the collision energy range 1–100 meV. The thermal rate coefficient was deduced from the cross-section to be α(T) = (1.10 ± 0.15) × 10−6 × (T/300)−(0.79±0.03) cm3/s. The reported branching fractions for C4D2+ agree with previous experiments on the DR of C4H2+ performed at the ASTRID storage ring in Aarhus, Denmark, and furthermore, indicate that the DR of C4D2+ possesses only two channels leading to the following products: C4D + D (75%) and C2D + C2D (25%).

  • 24. Dassanayake, B. S.
    et al.
    Das, Susanta
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Ayyad, A.
    Bereczky, R. J.
    Tokesi, K.
    Tanis, J. A.
    Charge evolution and energy loss associated with electron transmission through a macroscopic single glass capillary2011In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 269, no 11, p. 1243-1247Article in journal (Refereed)
    Abstract [en]

    Charge (time) evolution and the angular dependence of incident electrons in the range 300-1030 eV through a single macroscopic glass capillary was studied. Charge measurements were done at a sample tilt angle of psi = 2' for observation angles 0= O' and 05 (both psi and 0 were measured with respect to the incident beam direction) at incident energies of 520.7 and 824.5 eV using a parallel-plate spectrometer. After equilibrium of transmission, electrons had lower average centroid (mean) energies than the respective primary beam values. Centroid energies of transmitted electrons at the centroid of the angular distribution (where the observation angle 0 is nearly equal to tilt angle of the sample psi) were found to decrease exponentially with increasing sample tilt angles for all the measured electron energies. This energy loss is attributed to inelastic scattering of electrons with the inner wall of the sample close to the capillary entrance. Furthermore, the centroid energies of the transmitted electron angular distributions at 520.7 eV were found to lose energy for angular positions away from the capillary axis (angular centroid position) for all tilt angles, indicating a higher degree of inelastic scattering at the edges of the angular distributions.

  • 25. Dassanayake, B. S.
    et al.
    Das, Susanta
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Ayyad, A.
    Tanis, J. A.
    Electron transmission through a single glass macrocapillary: dependence on energy and time2011In: Physica Scripta, ISSN 0031-8949, E-ISSN 1402-4896, Vol. T144, p. 014041-Article in journal (Refereed)
    Abstract [en]

    The transmission of electrons through an insulating single cylindrically shaped glass capillary of macroscopic dimensions has been investigated for electron energies from 300 to 1000 eV using a high-resolution electrostatic parallel-plate analyzer (spectrometer). The transmitted intensity decreased with increasing sample tilt angle relative to the beam direction, and had two regions: direct, where there is no interaction of the beam with the inner capillary wall, and indirect, where it does interact. From the full-width-at-half-maximum of the angular distributions, the indirect region was found to reveal a further two distinct areas of characteristics versus tilt angle with respect to elasticity/inelasticity of transmitted electrons. Electron transmission for the case of no tilt of the sample was found to be time dependent, due to charge-up of the capillary inner surface. The new results are compared with previous experimental data obtained using a 10x lower resolution spectrometer.

  • 26.
    Ellman, A.
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Schef, P.
    Stockholm University, Faculty of Science, Department of Physics.
    Lundin, P.
    Stockholm University, Faculty of Science, Department of Physics.
    Royen, P.
    Stockholm University, Faculty of Science, Department of Physics.
    Mannervik, S.
    Stockholm University, Faculty of Science, Department of Physics.
    Fritioff, K.
    Andersson, P.
    Hanstorp, D.
    Froese Fischer, C.
    Österdahl, F.
    Pegg, D.J.
    Gibson, N.D.
    Danared, H.
    Källberg, A.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Radiative Lifetime of a Bound Excited State of Te-2004In: Physical Review Letters, ISSN 0031-9007, Vol. 92, no 25, p. 253002-Article in journal (Refereed)
    Abstract [en]

    We report on the first experimental study of the lifetime of a bound excited state of a negative ion. A new experimental technique was developed and used to measure the radiative lifetime of the 5p52P1/2 level of Te-. The experiment was performed in a magnetic storage ring, where a laser beam was applied along one of the straight sections. In the experiment the population of the excited J=1/2 level was probed each time the Te- ions passed through the laser field. A decay curve was built up by sampling the population of the excited level of the Te- ions as a function of time after injection into the ring. A multiconfiguration Dirac-Hartree-Fock calculation was performed in conjunction with the experiment. The calculation yielded a radiative lifetime of 0.45 s, in excellent agreement with the measured value of 0.42(5) s.

  • 27.
    Fischer, D.
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Gudmundsson, Magnus
    Stockholm University, Faculty of Science, Department of Physics.
    Berenyi, Zoltan
    Stockholm University, Faculty of Science, Department of Physics.
    Haag, Nicole
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, Henrik A. B.
    Stockholm University, Faculty of Science, Department of Physics.
    Misra, Deepankar
    Stockholm University, Faculty of Science, Department of Physics.
    Reinhed, Peter
    Stockholm University, Faculty of Science, Department of Physics.
    Kallberg, A.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Simonsson, Ansgar
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Stochkel, K.
    Cederquist, Henrik
    Stockholm University, Faculty of Science, Department of Physics.
    Schmidt, H. T.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Importance of Thomas single-electron transfer in fast p-He collisions2010In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 81, no 1, p. 12714-Article in journal (Refereed)
    Abstract [en]

    We report experimental angular differential cross sections for nonradiative single-electron capture in p-He collisions (p + He -> H + He+) with a separate peak at the 0.47 mrad Thomas scattering angle for energies in the 1.3-12.5 MeV range. We find that the intensity of this peak scales with the projectile velocity as v(P)(-11). This constitutes the first experimental test of the prediction from 1927 by L. H. Thomas [Proc. R. Soc. 114, 561 (1927)]. At our highest energy, the peak at the Thomas angle contributes with 13.5% to the total integrated nonradiative single-electron capture cross section.

  • 28.
    Fischer, D
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Støchkel, K
    Stockholm University, Faculty of Science, Department of Physics.
    Cederquist, H
    Stockholm University, Faculty of Science, Department of Physics.
    Zettergren, H
    Stockholm University, Faculty of Science, Department of Physics.
    Reinhed, P
    Stockholm University, Faculty of Science, Department of Physics.
    Schuch, R
    Stockholm University, Faculty of Science, Department of Physics.
    Källberg, Anders
    The Manne Siegbahn Laboratory (MSL).
    T. Schmidt, H
    Stockholm University, Faculty of Science, Department of Physics.
    Experimental separation of the Thomas charge transfer process in high velocity p-He collisions2006In: Physical Review A, Vol. 73, p. 052713-Article in journal (Refereed)
  • 29.
    Geppert, W.D.
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Hamberg, M.
    Stockholm University, Faculty of Science, Department of Physics.
    Thomas, R.D.
    Stockholm University, Faculty of Science, Department of Physics.
    Österdahl, F.
    Hellberg, F.
    Stockholm University, Faculty of Science, Department of Physics.
    Zhauernerchyk, V.
    Stockholm University, Faculty of Science, Department of Physics.
    Ehlerding, A.
    Stockholm University, Faculty of Science, Department of Physics.
    Millar, T.J.
    Roberts, H.
    Semaniak, J.
    af Ugglas, M.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Källberg, Anders
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Simonsson, Ansgar
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Kaminska, M.
    Larsson, M.
    Stockholm University, Faculty of Science, Department of Physics.
    Dissociative recombination of protonated methanol2006In: Journal of the Chemical Society, Faraday Transactions, ISSN 0956-5000, E-ISSN 1364-5455, Vol. 133, p. 177-190Article in journal (Refereed)
  • 30.
    Geppert, Wolf
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Hamberg, Mathias
    Stockholm University, Faculty of Science, Department of Physics.
    Thomas, Richard D.
    Stockholm University, Faculty of Science, Department of Physics.
    Österdahl, Fabian
    Stockholm University, Faculty of Science, Department of Physics.
    Hellberg, Fredrik
    Stockholm University, Faculty of Science, Department of Physics.
    Zhaunerchyk, Vitali
    Stockholm University, Faculty of Science, Department of Physics.
    Ehlerding, Anneli
    Stockholm University, Faculty of Science, Department of Physics.
    Millar, Tom
    Queen's University Belfast.
    Roberts, Helen
    Queen's University Belfast.
    Semaniak, Jacek
    Jan Kochanowski University, Kielce.
    af Ugglas, Magnus
    Stockholm University, Faculty of Science, Department of Physics.
    Källberg, Anders
    Stockholm University, Faculty of Science, Department of Physics.
    Simonsson, Ansgar
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Kaminska, Magdalena
    Jan Kochanowski University.
    Larsson, Mats
    Stockholm University, Faculty of Science, Department of Physics.
    Dissociative recombination of protonated methanol2006In: Faraday discussions (Online), ISSN 1359-6640, E-ISSN 1364-5498, Vol. 133, p. 177-190Article in journal (Refereed)
    Abstract [en]

    The branching ratios of the different reaction pathways and the overall rate coefficients of the dissociative recombination reactions of CH3OH2+ and CD3OD2+ have been measured at the CRYRING storage ring located in Stockholm, Sweden. Analysis of the data yielded the result that formation of methanol or deuterated methanol accounted for only 3 and 6% of the total rate in CH3OH2+ and CD3OD2+, respectively. Dissociative recombination of both isotopomeres mainly involves fragmentation of the C–O bond, the major process being the three-body break-up forming CH3, OH and H (CD3, OD and D). The overall cross sections are best fitted by s = 1.2 ± 0.1 × 10-15 E-1.15±0.02 cm2 and s = 9.6 ± 0.9 × 10-16 E-1.20±0.02 cm2 for CH3OH2+ and CD3OD2+, respectively. From these values thermal reaction rate coefficients of k(T) = 8.9 ± 0.9 ×10-7 (T/300)-0.59±0.02 cm3 s-1 (CH3OH2+) and k(T) = 9.1 ± 0.9 × 10-7 (T/300)-0.63±0.02 cm3 s-1(CD3OD2+) can be calculated. A non-negligible formation of interstellar methanol by the previously proposed mechanism via radiative association of CH3+ and H2O and subsequent dissociative recombination of the resulting CH3OH2+ ion to yield methanol and hydrogen atoms is therefore very unlikely.

  • 31.
    Guigas, R.
    et al.
    Kernforschungszentrum, Universität Karlsruche.
    Blüm, P.
    Kernforschungszentrum, Universität Karlsruche.
    Koch, H.
    Kernforschungszentrum, Universität Karlsruche.
    Meyer, M.
    Kernforschungszentrum, Universität Karlsruche.
    Poth, H.
    Kernforschungszentrum, Universität Karlsruche.
    Raich, U.
    Kernforschungszentrum, Universität Karlsruche.
    Richter, B.
    Kernforschungszentrum, Universität Karlsruche.
    Backenstoss, G.
    Pavlopoulos, P.
    Institute for Physics, University of Basle.
    Tauscher, L.
    Institute for Physics, University of Basle.
    Adiels, Lars
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Fransson, Kjell
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Nilsson, A.
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Suffert, M.
    Centre de recherches nucléaries and Université Louis Pasteur, Strabourg.
    Zioutas, K.
    Dept. of Nuclear Physics, Univerity of Tessaloniki.
    Strong interaction effects in antiprotonic 6Li/7Li atoms1984In: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 137, no 56, p. 323-328Article in journal (Refereed)
    Abstract [en]

    The effects of strong interaction on the 3 –> 2 X-ray transition in antiprotonic 6Li/7Li atoms have been measured at the low energy -beam at CERN. For the shifts and widths of the levels the values [epsilon]2p = (-230 ï¿œ 72) eV, [Gamma]2p = (443 ï¿œ 210) eV, and [Gamma]3d = (0.130 ï¿œ 0.045) eV for 6Li, and [epsilon]2p = (-336 ï¿œ 60) eV, [Gamma]2p = (456 ï¿œ 190) eV, and [Gamma]3d = (0.210 ï¿œ 0.062) eV for 7Li were found. The data are compared with optical model predictions.

  • 32. Gålnander, Björn
    et al.
    Bergmark, Torsten
    Byström, O
    Johnson, S
    Johnson, T
    Lofsnäs, Tor
    Norman, Gunnar
    Peterson, T
    Rathsman, Karin
    Reistad, Dag
    Danared, Håkan
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Status of Design Work towards an Electron Cooler for HESR2007In: COOL 2007, 2007Conference paper (Other academic)
  • 33. Gålnander, Björn
    et al.
    Bergmark, Torsten
    Johnson, S.
    Johnson, T.
    Lofnes, Tor
    Norman, Gunnar
    Peterson, T.
    Rathsman, Karin
    Reistad, Dag
    Danared, Håkan
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Status of Electron Cooler Design for HESR2008In: European Particle Accelerator Conference 2008, 2008Conference paper (Other academic)
  • 34.
    Hamberg, Mathias
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Kashperka, Iryna
    Stockholm University, Faculty of Science, Department of Physics.
    Danielsson, Mathias
    af Ugglas, Magnus
    Stockholm University, Faculty of Science, Department of Physics.
    Österdahl, Fabian
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Zhaunerchyk, Vitali
    Stockholm University, Faculty of Science, Department of Physics.
    Thomas, Richard D.
    Stockholm University, Faculty of Science, Department of Physics.
    Vigren, Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Kaminska, Magdalena
    Jan Kochanowski University, Kielce, Poland.
    Källberg, Anders
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Simonsson, Ansgar
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Paál, András
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Larsson, Mats
    Stockholm University, Faculty of Science, Department of Physics.
    Geppert, Wolf
    Stockholm University, Faculty of Science, Department of Physics.
    Experimental studies on the dissociative recombination of H13CO+ with electrons at energies between 2 – 50 000 meVManuscript (preprint) (Other academic)
    Abstract [en]

    Determination of dissociative recombination processes of H13CO+ using merged ion-electron beam methods has been performed at the heavy storage ring CRYRING, Stockholm, Sweden. We have measured the branching fractions at ~0 eV as: CO+H 87±2%, OH+C 9±2% and O+CH 4±2%. The channels leading to CO+H have the following branching fractions between the accessible electronic states of CO(X1S+)+H 46±3%, CO(a3Pg)+H 20±1% and CO(a’3S+)+H 34±3% respectively. The reaction cross section was fitted between 1-300 meV and followed the expression σ = 1.2±0.25×10-16 E-1.32±0.02 cm2 and the corresponding thermal rate constant was determined to k(T) = 2.0±0.4×10−7(T/300)−0.82±0.02 cm3s−1. The cross sections between ~2-50 000 meV were investigated showing resonant structures between 3-15 eV.

  • 35.
    Hamberg, Mathias
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Zhaunerchyk, Vitali
    Stockholm University, Faculty of Science, Department of Physics.
    Vigren, Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Kaminska, Magdalena
    Jan Kochanowski University, Kielce, Poland.
    Kashperka, Iryna
    Stockholm University, Faculty of Science, Department of Physics.
    Zhang, Mingwu
    Institute of Modern Physics.
    Trippel, Sebastian
    Albert-Ludwigs-Universität Freiburg, Tyskland.
    Österdahl, Fabian
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    af Ugglas, Magnus
    Stockholm University, Faculty of Science, Department of Physics.
    Thomas, Richard D.
    Stockholm University, Faculty of Science, Department of Physics.
    Källberg, Anders
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Simonsson, Ansgar
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Paál, András
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Larsson, Mats
    Stockholm University, Faculty of Science, Department of Physics.
    Geppert, Wolf
    Stockholm University, Faculty of Science, Department of Physics.
    Experimental studies of the dissociative recombination for CD3CDOD+ and CH3CH2OH2+Manuscript (preprint) (Other academic)
    Abstract [en]

    Aims:  Determination of branching fractions, cross sections and thermal rate constants for the dissociative recombination of CD3CDOD+ and CH3CH2OH2+ at the low relative kinetic energies encountered in the interstellar medium.

    Methods: The experiments were carried out by merging an ion and electron beam at the heavy ion storage ring CRYRING, Stockholm, Sweden.

    Results: Break-up of the CCO structure into three heavy fragments is not found for either of the ions. Instead the CCO structure is retained in 23 ± 3% of the DR reactions of CD3CDOD+ and 7 ± 3% in the DR of CH3CH2OH2+, whereas rupture into two heavy fragments occurs in 77 ± 3% and 93 ± 3% of the DR events of the respective ions. The measured cross sections were fitted between 1-200 meV yielding the following thermal rate constants and cross-section dependencies on the relative kinetic energy: σ(Ecm[eV]) = 1.7 ± 0.3 × 1015(Ecm[eV])1.23±0.02 cm2 and k(T) = 1.9 ± 0.4 × 106(T/300)0.73±0.02 cm3s1 for CH3CH2OH2+  as well as k(T) = 1.1 ± 0.4 × 106(T/300)0.74±0.05 cm3s1 and σ(Ecm[eV]) = 9.2 ± 4 × 1016(Ecm[eV])1.24±0.05 cm2 for CD3CDOD+.

  • 36.
    Hamberg, Mathias
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Österdahl, Fabian
    Stockholm University, Faculty of Science, Department of Physics.
    Thomas, Richard D.
    Stockholm University, Faculty of Science, Department of Physics.
    Zhaunerchyk, Vitali
    Stockholm University, Faculty of Science, Department of Physics.
    Vigren, Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Kaminska, Magdalena
    Jan Kochanowski University.
    af Ugglas, Magnus
    Stockholm University, Faculty of Science, Department of Physics.
    Källberg, Anders
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Simonsson, Ansgar
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Paál, András
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Larsson, Mats
    Geppert, Wolf D.
    Stockholm University, Faculty of Science, Department of Physics.
    Experimental studies of the dissociative recombination processes for the dimethyl ether ions CD3OCD2+ and (CD3)2OD+2010In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 514, p. A83-Article in journal (Refereed)
    Abstract [en]

    Aims: Determination of branching fractions, cross sections and thermal rate coefficients for the dissociative recombination of CD3OCD2+ (0-0.3 eV) and (CD3)2OD+ (0-0.2 eV) at the low relative kinetic energies encountered in the interstellar medium.

    Methods: The measurements were carried out using merged electron and ion beams at the CRYRING storage ring, Stockholm, Sweden.

    Results: For (CD3)2OD+ we have experimentally determined the branching fraction for ejection of a single hydrogen atom in the DR process to be maximally 7% whereas 49% of the reactions involve the break up of the COC chain into two heavy fragments and 44% ruptures both C-O bonds. The DR of CD3OCD2+ is dominated by fragmentation of the COC chain into two heavy fragments. The measured thermal rate constants and cross sections are k(T) =1.7 ± 0.5 × 106(T/300)0.77±0.01 cm3s−1,  σ= 1.2 ± 0.4 × 1015(Ecm[eV])1.27 ± 0.01 cm2 and k(T) = 1.7 ± 0.6 × 106(T/300)0.70±0.02 cm3s1,σ= 1.7 ± 0.6 × 1015(Ecm[eV])1.20±0.02 cm2 for CD3OCD2+ and (CD3)2OD+, respectively.

  • 37.
    Hamberg, Mattias
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Geppert, Wolf D
    Stockholm University, Faculty of Science, Department of Physics.
    Thomas, Richard D
    Stockholm University, Faculty of Science, Department of Physics.
    Zhaunerchyk, Vitali
    Stockholm University, Faculty of Science, Department of Physics.
    Österdahl, Fabian
    Stockholm University, Faculty of Science, Department of Physics.
    Ehlerding, Anneli
    Stockholm University, Faculty of Science, Department of Physics.
    Kaminska, Magdalena
    Stockholm University, Faculty of Science, Department of Physics.
    Semaniak, Jacek
    af Ugglas, Magnus
    Stockholm University, Faculty of Science, Department of Physics.
    Källberg, Anders
    The Manne Siegbahn Laboratory (MSL).
    Paál, Andras
    The Manne Siegbahn Laboratory (MSL).
    Simonsson, Ansgar
    The Manne Siegbahn Laboratory (MSL).
    Larsson, Mats
    Stockholm University, Faculty of Science, Department of Physics.
    Experimental determination of dissociative recombination of CH2OH+, CD2OD+, and CD2+2007In: Molecular Physics, Vol. 105, no 5-7, p. 899-906Article in journal (Refereed)
  • 38. He, Mianhong
    et al.
    Liljeby, Leif
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    et, al.
    Progress at the Shanghai EBIT2007In: 13th International Conference on the Physics of Highly Charged Ions, 2007, p. 419-422Conference paper (Other academic)
  • 39.
    Hedqvist, Anders
    et al.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Danared, Håkan
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Hellberg, Fredrik
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Field Characterization of XFEL Quadrupole Magnets2008In: European Particle Accelerator Conference 2008, 2008Conference paper (Other academic)
  • 40.
    Hellberg, Fredrik
    et al.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Danared, Håkan
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Hedqvist, Anders
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Decking, W.
    Krause, B.
    Petrov, A.
    Pflüger, J.
    Schmitz, M.
    Low Power Consuming Hybrid Bending Magnet at the XFEL Beam Dump2007In: FEL 2007, 2007Conference paper (Other academic)
  • 41. Hu, W.
    et al.
    Fu, Y.
    Gong, Y.
    Yao, K.
    Lu, D.
    Cheng, W.
    Liu, Y.
    Yang, Y.
    Xiao, J.
    Wu, S.
    Geng, Z.
    Huang, M.
    Zhang, X.
    Hutton, Roger
    Liljeby, Leif
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Progress and research at the Shanghai EBIT2008In: Canadian Journal of Physics, Vol. 86, no 1Article in journal (Other (popular science, discussion, etc.))
  • 42. Lindahl, A. O.
    et al.
    Andersson, P.
    Collins, G. F.
    Hanstorp, Dag
    Geppert, Wolf D.
    Stockholm University, Faculty of Science, Department of Physics.
    Hamberg, Mattias
    Stockholm University, Faculty of Science, Department of Physics.
    Thomas, Richard D.
    Stockholm University, Faculty of Science, Department of Physics.
    Zhaunerchyk, Vitali
    Stockholm University, Faculty of Science, Department of Physics.
    Diehl, C.
    Gibson, N. D.
    Källberg, Anders
    The Manne Siegbahn Laboratory (MSL).
    Pegg, D. J.
    Experimental investigation of electron impact on Si2−2008In: Physical Review A, Vol. 77, no 2Article in journal (Other (popular science, discussion, etc.))
  • 43.
    Löfgren, Patrik
    et al.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Andler, Guillermo
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Bagge, Lars
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Björkhage, Mikael
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Blom, Mikael
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Danared, Håkan
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Källberg, Anders
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Leontein, Sven
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Liljeby, Leif
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Paal, Andras
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Rensfelt, K-G.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Simonsson, Ansgar
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Cederquist, Henrik
    Department of Physics.
    Larsson, Mats
    Department of Physics.
    Rosén, Stefan
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory (MSL).
    Schmidt, Henning T.
    Department of Physics.
    Status of the Electrostatic and Cryogenic Double Ring Desirée2008In: European Particle Accelerator Conference 2008, 2008Conference paper (Other (popular science, discussion, etc.))
  • 44.
    Misra, Deepankar
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Schmidt, Henning Thordal
    Stockholm University, Faculty of Science, Department of Physics.
    Gudmundsson, Magnus
    Stockholm University, Faculty of Science, Department of Physics.
    Fischer, Daniel
    Max-Planck Institut, Heidelberg.
    Haag, Nicole
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, Henrik A B
    Stockholm University, Faculty of Science, Department of Physics.
    Källberg, Anders
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Najjari, B
    Max-Planck Institut, Heidelberg.
    Reinhed, Peter
    Stockholm University, Faculty of Science, Department of Physics.
    Schuch, Reinhold
    Stockholm University, Faculty of Science, Department of Physics.
    Schöffler, Marcus
    Frankfurt University.
    Simonsson, Ansgar
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Voitkiv, A B
    Max-Planck Institut, Heidelberg.
    Cederquist, Henrik
    Stockholm University, Faculty of Science, Department of Physics.
    Two-Center Double-Capture Interference in Fast He2++H2 Collisions2009In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 102, no 15, p. 153201-Article in journal (Refereed)
    Abstract [en]

    We report the first observation of Young-type interference effects in a two-electron transfer process. These effects change strongly as the projectile velocity changes in fast (1.2 and 2.0 MeV) He^{2+}-H_2 collisions as manifested in strong variations of the double-electron capture rates with the H_2 orientation. This is consistent with fully quantum mechanical calculations, which ignore sequential electron transfer, and a simple projectile de Broglie wave picture assuming that two-electron transfer probabilities are higher in collisions where the projectile passes close to either one of the H_2 nuclei.

  • 45.
    Mohamed, T.
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Andler, Guillermo
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Fogle, M.
    Stockholm University, Faculty of Science, Department of Physics.
    Justiniano, E.
    Madzunkov, S.
    Stockholm University, Faculty of Science, Department of Physics.
    Schuch, Reinhold
    Stockholm University, Faculty of Science, Department of Physics.
    Effects of polarization on laser-induced electron-ion recombination2011In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 83, no 3, p. 032702-Article in journal (Refereed)
    Abstract [en]

    The polarization dependence of laser-induced radiative recombination (LIR) to D(+) ions was investigated in the electron cooler of the CRYRING storage ring. The LIR gain as a function of wavelength into n = 3 principal quantum states of deuterium was measured at laser beam polarization angles of 0 degrees and 90 degrees with respect to the direction of the motional electric field in the interaction region. For the case of the polarization vector parallel to the external field, there is a double-peak structure in the gain curve that indicates a polarization effect in the LIR process. The two polarization directions also reveal a different width for the respective gain curves, giving additional evidence for the polarization effect, clearly seen by the behavior of a defined polarization parameter. The obtained polarization effect indicates a high sensitivity in recombination processes to external fields.

  • 46.
    Nagy, Sz
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Fritioff, T
    Stockholm University, Faculty of Science, Department of Physics.
    Bergström, I
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Blaum, K
    Stockholm University, Faculty of Science, Department of Physics.
    Suhonen, M
    Stockholm University, Faculty of Science, Department of Physics.
    Schuch, R
    Stockholm University, Faculty of Science, Department of Physics.
    High-precision mass measurements for fundamental applications using highly-charged ions with SMILETRAP2007In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 58, p. 109-112Article in journal (Refereed)
    Abstract [en]

    The Penning trap mass spectrometer SMILETRAP takes advantage of highly-charged ions for high-accuracy mass measurements. In this paper recent mass measurements on Li and Ca ions are presented and their impact on fundamental applications discussed, especially the need for accurate mass values of hydrogen-like and lithium-like ions in the evaluation of the electron g-factor measurements in highly-charged ions is emphasized. Such experiments aim to test bound state quantum electrodynamics. Here the ionic mass is a key ingredient, which can be the limiting factor for the final precision.

  • 47.
    Nagy, Sz.
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Fritioff, T.
    Suhonen, M.
    Stockholm University, Faculty of Science, Department of Physics.
    Schuch, R.
    Stockholm University, Faculty of Science, Department of Physics.
    Blaum, K.
    Björkhage, M.
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Bergström, I.
    New Mass Value for 7Li2006In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 96, no 16, p. 163004-Article in journal (Refereed)
  • 48.
    Orban, Istvan
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Altun, Zikri
    Department of Physics, Marmara University, 81040 Istanbul, Turkey.
    Källberg, Anders
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Simonsson, Ansgar
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Andler, Guillermo
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Paál, Andreas
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Blom, Mikael
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Löfgren, Patrik
    Stockholm University, Faculty of Science, The Manne Siegbahn Laboratory .
    Trotsenko, Sergiy
    GSI Gesellschaft für Schwerionenforschung, 64291 Darmstadt, Germany.
    Böhm, Sebastian
    Stockholm University, Faculty of Science, Department of Physics.
    Schuch, Reinhold
    Stockholm University, Faculty of Science, Department of Physics.
    Experimental dielectronic recombination rate coefficientsfor Na-like S VI and Na-like Ar VIII2009In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 498, p. 909-914Article in journal (Refereed)
    Abstract [en]

    Aims. Absolute recombination rate coefficients for two astrophysically relevant Na-like ions are presented.Methods. Recombination rate coefficients of S vi and Ar viii are determined from merged-beam type experiments at the CRYRINGelectron cooler. Calculated rate coefficients are used to account for recombination into states that are field-ionized and therefore notdetected in the experiment.Results. Dielectronic recombination rate coefficients were obtained over an energy range covering Δ n = 0 core excitations. ForNa-like Ar a measurement was also performed over the Δn = 1 type of resonances. In the low-energy part of the Ar viii spectrum,enhancements of more than one order of magnitude are observed as compared to the calculated radiative recombination. The plasmarecombination rate coefficients of the two Na-like ions are compared with calculated results from the literature. In the 103−104 Krange, large discrepancies are observed between calculated plasma rate coefficients and our data. At higher temperatures, above105 K, in the case of both ions our data is 30% higher than two calculated plasma rate coefficients, other data from the literaturehaving even lower values.Conclusions. Discrepancies below 104 K show that at such temperatures even state-of-the-art calculations yield plasma rate coefficientsthat have large uncertainties. The main reason for these uncertainties are the contributions from low-energy resonances, whichare difficult to calculate accurately.

  • 49.
    Orban, Istvan
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Glans, P.
    Altun, Z.
    Lindroth, Eva
    Stockholm University, Faculty of Science, Department of Physics.
    Källberg, Anders
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Schuch, Reinhold
    Stockholm University, Faculty of Science, Department of Physics.
    Determination of the recombination rate coefficients for Na-like Si IV forming Mg-like Si III2006In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 459, no 1, p. 291-296Article in journal (Refereed)
    Abstract [en]

    Aims. Absolute, total recombination rate coefficients for Si iv were determined using the CRYRING heavy-ion storage ring.Calculated rate coefficients were used to estimate recombination into states that could not be detected in the experiment becauseof field ionization. Total, as well as separate, radiative and dielectronic plasma recombination rate coefficients were determined.Methods. Stored ions were merged with an expanded electron beam in the electron cooler section of the storage ring. Recombined ionswere separated from the stored ion beam in the first dipole magnet after the electron cooler and were detected with unity efficiency.The absolute radiative and dielectronic recombination rate coefficients were obtained over a center-of-mass energy range of 0−20 eV,covering Δn = 0 core excitations up to the 3s → 3d series limit. The results of an intermediate coupling autostructure calculationwere compared with the experiment. The theoretical results were also used to estimate the contribution to dielectronic recombinationby high Rydberg states, which were not detected because of field ionization. The spectra were convoluted with Maxwell-Boltzmannenergy distributions in the 103−106 K temperature range.Results. The resulting plasma recombination rate coefficients are presented and compared with theoretical results frequently usedfor plasma modeling. In the 103−104 K range, a significant underestimation of the calculated dielectronic recombination plasma ratecoefficients was observed. Above 3 × 104 K, the agreement between our dielectronic recombination plasma rate coefficients and twoof the previously published rate coefficients is better than 20%.Conclusions. The observed differences between the experimental and calculated recombination rate coefficients at low temperaturesreflect the need for benchmarking experiments. Our experimentally-derived rate coefficients can guide the development of bettertheoretical models and lead to more accurately-calculated rate coefficients.

  • 50.
    Orbán, Istvan
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Böhm, Sebastian
    Stockholm University, Faculty of Science, Department of Physics.
    Fogle, Mickhael
    Paál, Andras
    Stockholm University, Faculty of Science, Department of Physics, The Manne Siegbahn Laboratory.
    Schuch, Reinhold
    Stockholm University, Faculty of Science, Department of Physics.
    A new method for detecting the contribution of high Rydberg states to electron-ion recombination2007In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 58, no 299, p. 299-302Article in journal (Refereed)
    Abstract [en]

    A position sensitive detector for measuring field ionized electrons in the fringe field of a dipole magnet is presented. The detector provides a means to study, in a state selective fashion, recombination into high Rydberg states and offers a new method to investigate recombination enhancement effects. Several experimental considerations and possibilities are discussed in the text.

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