Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
SMILETRAP I / II: Precision Improvements in Penning-Trap Mass-Spectrometry
Stockholm University, Faculty of Science, Department of Physics. (Atomfysik)
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis describes the final precision mass measurements with SMILETRAP I, where a relative precision of < 1 ppb (10-9) was reached routinely, and the development of SMILETRAP II, aiming for measurements with < 0.1 ppb relative precision. The emphasis of the thesis is on the implementation of new techniques for achieving this precision improvement with SMILETRAP II. The Ramsey multiple-pulse excitation technique was tested at SMILETRAP I, and a reduction of the statistical uncertainty by factor three could by verified. The technique was applied in the last measurement with SMILETRAP I on H2+ and D+ ions. From these measurements the proton mass was deduced with a relative error of 0.18 ppb. It was found that temperature dependent magnetic field oscillations limited us from reducing the uncertainties further. A technical achievement of reducing the peak to peak temperature oscillation in the trapping region of SMILETRAP II by a factor four is presented, which should give an extended observation time and likewise improved precision. The new SMILETRAP II super-conducting magnet, with a slightly stronger field of 5.8 T compared with the previous of 4.7 T, was installed and adjusted.  A careful field alignment and reduction of inhomogeneities was done for minimizing the disturbances of the cyclotron frequency for improved precision. In that attempt, the localization and control of the trapped ion motion is also important. Thus a new cooling trap was set up. In the spring of 2009 coherent axial motion of a confined ion cloud was discovered in the cooling trap. By observation of the axial oscillations we can see the effects of evaporative cooling in the reduction of the axial energy distribution. Storing the ions up to 1 s in the cooling trap reduces the energy distribution by a factor of five. Other remarkable results of the ion oscillations are also reported.

Place, publisher, year, edition, pages
Stockholm: Department of Physics, Stockholm University , 2009. , 78 p.
Keyword [en]
Penning trap, Mass spectrometers, Instrumentation and methods for time-of-flight (TOF) spectroscopy, Highly charged ions
National Category
Atom and Molecular Physics and Optics
Research subject
Physics
Identifiers
URN: urn:nbn:se:su:diva-29399ISBN: 978-91-7155-931-9 (print)OAI: oai:DiVA.org:su-29399DiVA: diva2:232902
Public defence
2009-09-25, sal FA31, AlbaNova universitetscentrum, Roslagstullsbacken 21, Stockholm, 10:00 (English)
Opponent
Supervisors
Note
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: In progress. Paper 3: Submitted.Available from: 2009-09-03 Created: 2009-08-26 Last updated: 2010-01-13Bibliographically approved
List of papers
1. First observation of evaporative cooling of highly charged ions in a Penning trap resolved by their coherent axial oscillations
Open this publication in new window or tab >>First observation of evaporative cooling of highly charged ions in a Penning trap resolved by their coherent axial oscillations
Show others...
(English)Manuscript (preprint) (Other academic)
Abstract [en]

We have trapped and stored Ar16+ ions in a cylindrical Penning trap and managed to evaporatively cool the ion clouds axial motion to thermal temperature. The stored ion cloud is excited axially by fast switching of the trap potentials whereafter the cloud starts to oscillate coherently. The cooling is observed from the time of flight resolved peaks originating from the oscillations while lowering the trap potential slowly. The peaks widths decrease with increased storage time.

Keyword
Penning Traps, TOF spectroscopy
National Category
Atom and Molecular Physics and Optics
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-29383 (URN)
Available from: 2009-08-26 Created: 2009-08-26 Last updated: 2010-01-14Bibliographically approved
2. Precise measurements of ionic masses for QED tests
Open this publication in new window or tab >>Precise measurements of ionic masses for QED tests
Show others...
2006 (English)In: International Journal of Mass Spectrometry, ISSN 1387-3806, E-ISSN 1873-2798, Vol. 251, no 2-3, 281-285 p.Article in journal (Refereed) Published
Abstract [en]

The Penning trap mass spectrometer SMILETRAP is designed for precision mass measurements using the merits of highly charged ions. In this paper we describe the feature of SMILETRAP and give examples of mass measurements involving , , and ions. These emphasize the importance of accurate masses of hydrogen-like and lithium-like ions that are required in the evaluation of g-factor measurements of electrons bound to even–even nuclei and test of QED effects. Highly precise mass measurements can also be used for testing atomic structure calculations and determining atomic binding energies. Relevance of such measurements throughout the periodic system is discussed.

Keyword
g-Factor; Penning trap; Lamor precision frequency; Isotopes; QED
National Category
Physical Sciences
Identifiers
urn:nbn:se:su:diva-12596 (URN)10.1016/j.ijms.2006.02.008 (DOI)
Available from: 2008-01-15 Created: 2008-01-15 Last updated: 2017-12-13Bibliographically approved
3. Improved temperature regulation of Penning trap mass spectrometers
Open this publication in new window or tab >>Improved temperature regulation of Penning trap mass spectrometers
Show others...
2010 (English)In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 294, no 1, 28-32 p.Article in journal (Refereed) Published
Abstract [en]

In order to reach relative uncertainties in mass measurements with Penning traps of 10-10 or better, the temperature variation of the trap and surrounding materials must be kept below 10 mK. Temperature variations induce a shift in the measured ion cyclotron frequency because of non-zero, temperature dependent magnetic susceptibilities of the construction materials. In this paper we report of a new temperature regulation system recently installed at SMILETRAP II that manages to keep the temperature fixed at the set point with a standard deviation of only 2.6 mK. −10 or better, the temperature variation of the trap and surrounding.

Keyword
Penning trap, Magnetic field, Stabilization, Precision mass spectrometry, Temperature regulation
National Category
Atom and Molecular Physics and Optics
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-29382 (URN)10.1016/j.ijms.2010.04.008 (DOI)000279462700005 ()
Available from: 2009-08-26 Created: 2009-08-26 Last updated: 2017-12-13Bibliographically approved
4. New Mass Value for 7Li
Open this publication in new window or tab >>New Mass Value for 7Li
Show others...
2006 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 96, no 16, 163004- p.Article in journal (Refereed) Published
Identifiers
urn:nbn:se:su:diva-34862 (URN)10.1103/PhysRevLett.96.163004 (DOI)
Available from: 2010-01-13 Created: 2010-01-13 Last updated: 2017-12-12Bibliographically approved
5. High-precision mass measurements for fundamental applications using highly-charged ions with SMILETRAP
Open this publication in new window or tab >>High-precision mass measurements for fundamental applications using highly-charged ions with SMILETRAP
Show others...
2007 (English)In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 58, 109-112 p.Article in journal (Refereed) Published
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.

National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:su:diva-11017 (URN)10.1088/1742-6596/58/1/018 (DOI)
Available from: 2008-01-10 Created: 2008-01-10 Last updated: 2017-12-13Bibliographically approved
6. Q value related mass determinations using a Penning trap
Open this publication in new window or tab >>Q value related mass determinations using a Penning trap
Show others...
2007 (English)In: Hyperfine Interactions, ISSN 0304-3843, E-ISSN 1572-9540, Vol. 173, no 1-3, 73-83 p.Article in journal (Refereed) Published
Abstract [en]

We report here about measurements of reaction and decay Q values by precise determination of pairs of atomic masses. These were performed with the Penning trap mass spectrometer SMILETRAP. Measurements with Penning traps give reliable and accurate masses, in particular Q values, due to the fact that certain systematic errors to a great deal cancel in the mass difference between the two atoms defining the Q value. Some Q values that are of fundamental interest will be discussed here, for example, a new Q value for the 6Li (n,γ) 7Li reaction, for the β-decay of tritium, related to properties of the electron neutrino mass, and for the neutrino-less double β-decay of 76Ge, related to the question of whether the neutrino is a Majorana particle or not. In case of the latter two we report the most accurate Q values, namely 18,589.8(12) eV for the tritium decay and 2,038.997(46) keV for the neutrino-less double β-decay of 76Ge.

Place, publisher, year, edition, pages
Nederländerna: Springer, 2007
Keyword
Penning trap, Precision mass determinations, Q value, SMILETRAP
National Category
Atom and Molecular Physics and Optics
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-29375 (URN)10.1007/s10751-007-9545-0 (DOI)
Available from: 2009-08-25 Created: 2009-08-25 Last updated: 2017-12-13Bibliographically approved
7. Precise Atomic Masses for Fundamental Physics Determined at SMILETRAP
Open this publication in new window or tab >>Precise Atomic Masses for Fundamental Physics Determined at SMILETRAP
Show others...
2008 (English)In: Advances in Quantum Chemistry, ISSN 0065-3276, E-ISSN 2162-8815, Vol. 53, 67-81 p.Article in journal (Refereed) Published
Abstract [en]

In this paper we describe the features of the SMILETRAP Penning trap mass spectrometer and give examples of recently performed precision mass measurements. SMILETRAP is designed for precision mass measurements using the merits of highly-charged ions. We emphasize here the importance of accurate masses of hydrogen-like and lithium-like ions for the evaluation of g-factor measurements of electrons bound to even–even nuclei and test quantum electrodynamics (QED). For these experiments the ion masses of 40Ca17+ and 40Ca19+ were measured at SMILETRAP with 5×10−10 precision. Highly precise mass measurements can also be used for testing atomic structure calculations and determination of atomic and nuclear binding energies. Some Q-values are of fundamental interest, for example, the beta-decay of tritium and the double beta-decay with no neutrinos of several nuclei, in particular 76Ge. These decays are related to properties of the electron neutrino mass and whether this neutrino is a Majorana particle. The reason that Penning traps are so reliable for the determinations of accurate decay Q-values is due to the fact that systematic errors to a great deal cancel in the mass difference between the two atoms defining the Q-value. In this paper we report the most accurate Q-values of these two beta decays namely 18589.8(12) eV for the tritium decay, and 2038.997(46) keV for the neutrinoless double beta-decay of 76Ge.

Place, publisher, year, edition, pages
Nederländerna: Elsevier, 2008
National Category
Physical Sciences
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-29380 (URN)10.1016/S0065-3276(07)53006-6 (DOI)000251354200006 ()
Available from: 2009-08-25 Created: 2009-08-25 Last updated: 2017-12-13Bibliographically approved
8. Determination of the proton mass from a measurement of the cyclotron frequencies of D+ and H2+ in a Penning trap
Open this publication in new window or tab >>Determination of the proton mass from a measurement of the cyclotron frequencies of D+ and H2+ in a Penning trap
Show others...
2008 (English)In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 78, no 1, 2514-2520 p.Article in journal (Refereed) Published
Abstract [en]

We determine the cyclotron frequency ratio of H2+ and D+, applying the two-pulse Ramsey-excitation technique in the Penning-trap mass spectrometer SMILETRAP. The final result, based on probing more than 100 000 ions, is a frequency ratio of 0.999 231 659 33(17). Using a value of the D+ mass recently measured by the Seattle group, we obtain so far the most precise experimental H2+ mass value of 2.015 101 497 16(34) u. From this value a proton mass value of 1.007 276 466 95(18) u (0.18 ppb relative uncertainty) could be derived, in good agreement with the value of 1.007 276 466 89(14) u published by Van Dyck et al.

Place, publisher, year, edition, pages
Maryland, USA: American Physical Society, 2008
Keyword
atomic mass, deuterium, hydrogen ions, mass spectra, mass spectroscopy, particle traps, protons
National Category
Atom and Molecular Physics and Optics
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-29381 (URN)10.1103/PhysRevA.78.012514 (DOI)000258180300118 ()
Available from: 2009-08-26 Created: 2009-08-26 Last updated: 2017-12-13Bibliographically approved
9. High-frequency Ramsey excitation in a Penning trap
Open this publication in new window or tab >>High-frequency Ramsey excitation in a Penning trap
Show others...
2007 (English)In: Journal of instrumentation, ISSN 1748-0221, Vol. 2, no P06003, 1-14 p.Article in journal (Refereed) Published
Abstract [en]

The Ramsey excitation method for high-precision mass-measurements of highly-charged ions has been investigated and benchmarked using H2+ ions in the Penning-trap mass-spectrometer SMILETRAP. The reason for using H2+ ions are their high cyclotron frequency which is typical for the highly-charged ions usually used at SMILETRAP. Two-, three- and four-pulse Ramsey excitation data are analyzed with the help of recent theoretical work and are compared with the previously used single-pulse excitation data. An improvement factor of 2.9 in the statistical uncertainty is achieved. Furthermore the mass of 76Se, included in the previous Q-value measurement of the 76Ge neutrinoless double beta decay, is checked using 76Se25+ ions and a three-pulse Ramsey excitation. The results show a convincing agreement with the measurement when using single-pulse excitation and therefore our Q-value of 2039.006(50) keV, performed with single-pulse excitation, is confirmed.

Place, publisher, year, edition, pages
England/Italien: IOP, SISSA, 2007
Keyword
Mass spectrometers, Instrumentation and methods for time-of-flight (TOF) spectroscopy, Analysis and statistical methods
National Category
Atom and Molecular Physics and Optics
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-29366 (URN)10.1088/1748-0221/2/06/P06003 (DOI)000253651600003 ()
Available from: 2009-08-25 Created: 2009-08-25 Last updated: 2011-04-27Bibliographically approved

Open Access in DiVA

fulltext(2372 kB)252 downloads
File information
File name FULLTEXT01.pdfFile size 2372 kBChecksum SHA-512
1158d0846d55984300e38d11073bdf1cb615ac5f7da98f5c514bf3c10e8c30d00a36ab43dfc2cc8639f36dc561dfdbdc6c859bccfbd7b21dceb0fb264c9c54e5
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Suhonen Linné, Markus
By organisation
Department of Physics
Atom and Molecular Physics and Optics

Search outside of DiVA

GoogleGoogle Scholar
Total: 252 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 228 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf