Publications (35)12.9 Total impact
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Article: Experimental test of special relativity by laser spectroscopy
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ABSTRACT: The Doppler-free laser-spectroscopic frequency measurement of Doppler-shifted optical lines in forward and backward direction of a fast ion beam permits a sensitive test of the relativistic Doppler-formula and, hence, the relativistic time dilation factor gSR = ( 1 - n2 \mathord/ \vphantom n2 c2 c2 ) - 1 \mathord/ \vphantom - 1 2 2 \gamma _{{SR}} = {\left( {1 - {\nu ^{2} } \mathord{\left/ {\vphantom {{\nu ^{2} } {c^{2} }}} \right. } {c^{2} }} \right)}^{{{ - 1} \mathord{\left/ {\vphantom {{ - 1} 2}} \right. } 2}} . An experiment on metastable 7Li+, stored at a velocity of v = 0.064c in the Heidelberg heavy-ion storage ring TSR, has confirmed time dilation with unprecedented accuracy. Latest tests at two different ion-velocities (v = 0.03c and v = 0.064c) will enhance these measurements. An improved version of this experiment will be carried out at the experimental storage ring (ESR) at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt. The ESR permits 7Li+ to be stored at v = 0.33c which promises an improvement of the sensitivity to deviations from γ SR by an order of magnitude. A first test at the ESR has shown the feasibility for this kind of experiment.Hyperfine Interactions 04/2012; 171(1):57-67. · 0.21 Impact Factor -
Article: Comment on: “Lorentz violation in high-energy ions” by Santosh Devasia
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ABSTRACT: In an article “Lorentz violation in high-energy ions” by S. Devasia published in this Journal [EPJ C 69, 343 (2010)], our recent Doppler shift experiments on fast ion beams are reanalyzed. Contrary to our analysis, Devasia concludes that our results provide an “indication of Lorentz violation”. We argue that this conclusion is based on a fundamental misunderstanding of our experimental scheme and reiterate that our results are in excellent agreement with Special Relativity.European Physical Journal C 04/2012; 71(3):1-2. · 3.63 Impact Factor -
Article: Comment on "Missing Transverse-Doppler Effect in Time-Dilation Experiments with High-Speed Ions"
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ABSTRACT: In an article "Missing Transverse-Doppler Effect in Time-Dilation Experiments with High-Speed Ions" by S. Devasia [arXiv:1003.2970v1], our recent Doppler shift experiments on fast ion beams are reanalyzed. Contrary to our analysis, Devasia concludes that our results provide an "indication of Lorentz violation". We argue that this conclusion is based on a fundamental misunderstanding of our experimental scheme and reiterate that our results are in excellent agreement with Special Relativity.02/2011; -
Chapter: Experimental Test of Time Dilation by Laser Spectroscopy on Fast Ion Beams
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ABSTRACT: The Ives-Stilwell experiment – measuring the time dilation relation γSR = (1 – β 2)–½ – is one of the three classic experiments to test Special Relativity. Together with the interferometric tests of the velocity-independence as well as the isotropy of the speed of light, governed by the Michelson-Morley and the Kennedy-Thorndike experiment, respectively, the Ives-Stilwell experiment entirely establishes Special Relativity on an experimental basis and replaces Einsteins postulates [1]. While the interferometric experiments are ‘nullexperiments’ looking for deviations of the constancy of the speed of light, the time dilation test provides a positive measurement based on a Lorentz boost. It was Einstein who proposed already in 1907 to look for the time dilation effect by observing the Doppler-shifted wavelength of light emitted by excited fast atoms perpendicularly to the motion. In this direction, the classical Doppler effect vanishes leaving pure time dilation. However, it turned out that this scheme is difficult to implement as already small deviations of the observation angle from 90 degree would cause frequency shifts due to the classical Doppler effect which varies linearly around π/2. It took another 31 years until Ives and Stilwell performed the first measurement. Contrary to Einsteins idea they observed the Doppler shifts not perpendicularly but in forward and in backward direction of the atomic motion. This scheme provides different advantages. First, the classical Doppler shift vanishes in this scheme because it is of equal magnitude but opposite in sign in both directions of observation. Secondly, the measurement is less sensitive to small misalignments as the classical Doppler shift varies only quadratically around 0 and π. And finally, as two frequencies are measured, both the time dilation factor as well as the atoms’ velocity can be extracted to an accuracy given by the frequency uncertainty. When observing perpendicularly, the velocity has to be determined separately to provide a test of the time dilation relation. In the next section the principle of the Ives-Stilwell experiment11/2006: pages 479-492; -
Chapter: Laser Cooling and Spectroscopy of Relativistic C3+ Beams at the ESR
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ABSTRACT: We report on the first laser cooling of a bunched beam of multiply charged C3+ ions performed at the ESR (GSI) at a beam energy of E = 1.47 GeV. Moderate bunching provided a force counteracting the decelerating laser force of one counterpropagating laser beam. This versatile type of laser cooling lead to longitudinally space-charge dominated beams with an unprecedented momentum spread of Δp/p ≈ 10−7. Concerning the beam energy and charge state of the ion, the experiment depicts an important intermediate step from the established field of laser cooling of ion beams at low energies toward the unique laser cooling scheme proposed for relativistic beams of highly charged heavy ions at SIS 300 (FAIR).08/2006: pages 181-188; -
Conference Proceeding: Laser Cooling of Relativistic Heavy Ion Beams
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ABSTRACT: We report on the experimental demonstration of laser cooling of a C<sup>3+</sup>ion beam performed at the ESR (GSI) at an energy of E = 1.47 GeV. The decelerating laser force of one Doppler-tuned UV laser beam was counteracted by moderately bunching the beam. This versatile scheme lead to longitudinally ‘space-charge dominated’ beams with an unprecedented momentum spread of Δp/p ≈ 10<sup>–7</sup>. Concerning beam energy and charge state of the ion, the experiment depicts an important step from the field of laser cooling of ion beams at low energies toward the laser cooling scheme proposed for relativistic beams of highly charged heavy ions at the future GSI facility FAIR.Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the; 06/2005 -
Article: Improved test of time dilation in special relativity.
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ABSTRACT: An improved test of time dilation in special relativity has been performed using laser spectroscopy on fast ions at the heavy-ion storage-ring TSR in Heidelberg. The Doppler-shifted frequencies of a two-level transition in 7Li+ ions at v=0.064c have been measured in the forward and backward direction to an accuracy of Deltanu/nu=1 x 10(-9) using collinear saturation spectroscopy. The result confirms the relativistic Doppler formula and sets a new limit of 2.2 x 10(-7) for deviations from the time dilation factor gamma(SR)=(1-v2/c2)(-1/2).Physical Review Letters 12/2003; 91(19):190403. · 7.37 Impact Factor -
Article: Laser-Cooled Ions and Atoms in a Storage Ring
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ABSTRACT: We review recent experiments at the Heidelberg Test Storage Ring which apply advanced laser cooling techniques to stored ion beams. Very high phase-space densities are achieved by three-dimensional laser cooling of a coasting beam at 7.3 MeV. Laser-cooled, trapped Cs atoms are used as an ultracold precision target for the study of ion-atom interactions with a 74 MeV beam of ions.03/2003; -
Article: Bunched laser cooling of a stored weak 7Li+ ion beam in a pure triplet state
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ABSTRACT: A preparation scheme for a 7Li+ ion beam in a storage ring is presented which provides ions in the metastable triplet states with well controlled longitudinal phase space properties. For both state selective preparation and beam cooling, laser- and electron-cooler forces are applied. The spatial- and momentum distributions of the ions are directly detected by a time resolved measurement of the fluorescence light. At low beam intensities, the remaining heating rate of such a beam is completely determined by residual gas scattering.Hyperfine Interactions 01/1998; 115(1):53-56. · 0.21 Impact Factor -
Article: Toward a New Test of the Relativistic Time Dilation Factor by Laser Spectroscopy of Fast Ions in a Storage Ring
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ABSTRACT: The frequency measurement of Doppler-shifted optical lines of ions circulating in a storage ring at high speed permits a sensitive test of the relativistic Doppler-formula and, hence, the time dilation factor γSR of special relativity. Previous measurements at the storage ring TSR with 7Li+ at v=0.065c gave a new, improved limit, but were hampered by the large observed linewidth, exceeding the natural width 15-fold. Recently we have identified the broadening to be caused by velocity-changing processes in the storage ring. Saturation spectroscopy has proven to be largely immune against these effects and has yielded linewidths only a few MHz larger than the natural one. This is the major ingredient for an improved test of γSR, which is now under way.Hyperfine Interactions, v.146-147, 1-4, 71-75 (2003). -
Article: Laser-Cooled Ions and Atoms in a Storage Ring
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ABSTRACT: We review recent experiments at the Heidelberg Test Storage Ring which apply advanced laser cooling techniques to stored ion beams. Very high phase-space densities are achieved by three-dimensional laser cooling of a coasting 9Be+ beam at 7.3 MeV. Laser-cooled, trapped Cs atoms are used as an ultracold precision target for the study of ion-atom interactions with a 74 MeV beam of 12C6+ ions.Hyperfine Interactions, v.146-147, 1-4, 189-195 (2003). -
Chapter: LASER SPECTROSCOPY ON RELATIVISTIC ION BEAMS
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ABSTRACT: Times Cited: 0pages 297-303; , ISBN: 978-981-4282-33-8 -
Article: Sub-Doppler laser spectroscopy on relativistic beams and tests of Lorentz invariance
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ABSTRACT: Times Cited: 580. -
Article: Experimental test of special relativity by laser spectroscopy
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ABSTRACT: Novotny, C. Bernhardt, B. Ewald, G. Geppert, C. Gwinner, G. Haensch, T. W. Holzwarth, R. Huber, G. Karpuk, S. Kluge, H. -J. Kuehl, T. Noertershaeuser, W. Reinhardt, S. Saathoff, G. Schwalm, D. Udem, T. Wolf, A.171:57-67. -
Article: Towards a precision test of time dilation at high velocity
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ABSTRACT: Times Cited: 187:749-756. -
Conference Proceeding: Bunched laser cooling of a stored weak Li-7(+) ion beam in a pure triplet state
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ABSTRACT: A preparation scheme for a Li-7(+) ion beam in a storage ring is presented which provides ions in the metastable triplet states with well controlled longitudinal phase space properties. For both state selective preparation and beam cooling, laser- and electron-cooler forces are applied. The spatial- and momentum distributions of the ions are directly detected by a time resolved measurement of the fluorescence light. At low beam intensities, the remaining heating rate of such a beam is completely determined by residual gas scattering. -
Article: Comment on: Lorentz violation in high-energy ions by Santosh Devasia
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ABSTRACT: Saathoff, G. Reinhardt, S. Holzwarth, R. Haensch, T. W. Udem, Th Bing, D. Schwalm, D. Wolf, A. Karpuk, S. Huber, G. Novotny, C. Botermann, B. Geppert, C. Noertershaeuser, W. Kuehl, T. Stoehlker, T. Gwinner, G.71. -
Article: Bunched laser cooling of a stored weak Li-7(+) ion beam in a pure triplet state
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ABSTRACT: Merz, P Grieser, R Huber, G Karpuk, S Sebastian, V Seelig, P Grieser, M Grimm, R Lauer, I Luger, V Schwalm, D Dax, A Engel, T Gerlach, M Kuhl, T Winter, H115:53-56. -
Chapter: The dynamics of bunched laser-cooled ion beams at relativistic energies
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ABSTRACT: Bussmann, M. Schramm, U. Habs, D. Steck, M. Kuehl, T. Beckert, K. Beller, P. Franzke, B. Noertershaeuser, W. Geppert, C. Novotny, C. Kluge, J. Nolden, F. Stoehlker, T. Kozhuharov, C. Reinhardt, S. Saathoff, G. Karpuk, S.ISBN: 1742-6588 -
Article: Laser cooling and Spectroscopy of relativistic C3+ beams at the ESR
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ABSTRACT: Schramm, U Bussmann, M Habs, D Steck, M Kuhl, T Beckert, K Beller, P Franzke, B Nolden, F Saathoff, G Reinhardt, S Karpuk, S162:181-188.
Top co-authors
Top Journals
Institutions
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2006–2012
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Johannes Gutenberg-Universität Mainz
- Institute of Physics
Mainz, Rhineland-Palatinate, Germany
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2003
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Max-Planck-Institut für Kernphysik
Heidelberg, Baden-Wuerttemberg, Germany
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