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Geppert P, Althön M, Fichtner D, Ott H. Diffusive-like redistribution in state-changing collisions between Rydberg atoms and ground state atoms. Nat Commun 2021; 12:3900. [PMID: 34162846 PMCID: PMC8222215 DOI: 10.1038/s41467-021-24146-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 06/01/2021] [Indexed: 12/03/2022] Open
Abstract
Exploring the dynamics of inelastic and reactive collisions on the quantum level is a fundamental goal in quantum chemistry. Such collisions are of particular importance in connection with Rydberg atoms in dense environments since they may considerably influence both the lifetime and the quantum state of the scattered Rydberg atoms. Here, we report on the study of state-changing collisions between Rydberg atoms and ground state atoms. We employ high-resolution momentum spectroscopy to identify the final states. In contrast to previous studies, we find that the outcome of such collisions is not limited to a single hydrogenic manifold. We observe a redistribution of population over a wide range of final states. We also find that even the decay to states with the same angular momentum quantum number as the initial state, but different principal quantum number is possible. We model the underlying physical process in the framework of a short-lived Rydberg quasi-molecular complex, where a charge exchange process gives rise to an oscillating electric field that causes transitions within the Rydberg manifold. The distribution of final states shows a diffusive-like behavior.
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Affiliation(s)
- Philipp Geppert
- Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, Kaiserslautern, Germany
| | - Max Althön
- Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, Kaiserslautern, Germany
| | - Daniel Fichtner
- Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, Kaiserslautern, Germany
| | - Herwig Ott
- Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, Kaiserslautern, Germany.
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2
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Fang F, Zhou W, Li Y, Qian D, Luo C, Zhao D, Ma X, Yang J. Design and characterization of a velocity-map imaging apparatus for low-energy photo-ion spectroscopy using magneto-optically trapped atoms. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:043103. [PMID: 34243435 DOI: 10.1063/5.0033595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 03/26/2021] [Indexed: 06/13/2023]
Abstract
We present a velocity-map imaging (VMI) apparatus coupled with a magneto-optical trap (MOT) of 87Rb atoms designed for low-energy photo-ion spectroscopy. The VMI-electrode geometry uses a three-electrode configuration, and the focusing electric field is optimized based on systematic simulations of relatively low-energy ions. To calibrate the apparatus, we use resonant two-color two-photon ionization of rubidium atoms as Doppler-selected ions. This VMI system provides an accuracy of 0.15 m/s and a resolution of 7.5 m/s for photoions with speeds below 100 m/s. Finally, details of the design, construction, and testing of the VMI-MOT system are presented.
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Affiliation(s)
- Feng Fang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Wenchang Zhou
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Yufan Li
- School of Physics and Electrical Engineering, Anyang Normal University, Anyang 455000, China
| | - Dongbin Qian
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Changjie Luo
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Dongmei Zhao
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Xinwen Ma
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Jie Yang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
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3
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Hubele R, Schuricke M, Goullon J, Lindenblatt H, Ferreira N, Laforge A, Brühl E, de Jesus VLB, Globig D, Kelkar A, Misra D, Schneider K, Schulz M, Sell M, Song Z, Wang X, Zhang S, Fischer D. Electron and recoil ion momentum imaging with a magneto-optically trapped target. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:033105. [PMID: 25832209 DOI: 10.1063/1.4914040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A reaction microscope (ReMi) has been combined with a magneto-optical trap (MOT) for the kinematically complete investigation of atomic break-up processes. With the novel MOTReMi apparatus, the momentum vectors of the fragments of laser-cooled and state-prepared lithium atoms are measured in coincidence and over the full solid angle. The first successful implementation of a MOTReMi could be realized due to an optimized design of the present setup, a nonstandard operation of the MOT, and by employing a switching cycle with alternating measuring and trapping periods. The very low target temperature in the MOT (∼2 mK) allows for an excellent momentum resolution. Optical preparation of the target atoms in the excited Li 2(2)P3/2 state was demonstrated providing an atomic polarization of close to 100%. While first experimental results were reported earlier, in this work, we focus on the technical description of the setup and its performance in commissioning experiments involving target ionization in 266 nm laser pulses and in collisions with projectile ions.
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Affiliation(s)
- R Hubele
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - M Schuricke
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - J Goullon
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - H Lindenblatt
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - N Ferreira
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - A Laforge
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - E Brühl
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - V L B de Jesus
- Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro (IFRJ), Rua Lucio Tavares 1045, 26530-060 Nilópolis, Rio de Janeiro, Brazil
| | - D Globig
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - A Kelkar
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - D Misra
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - K Schneider
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - M Schulz
- Physics Department and LAMOR, Missouri University of Science and Technology, Rolla, Missouri 65409, USA
| | - M Sell
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Z Song
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - X Wang
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - S Zhang
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - D Fischer
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
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4
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Leredde A, Fléchard X, Cassimi A, Hennecart D, Pons B. High-resolution probe of coherence in low-energy charge exchange collisions with oriented targets. PHYSICAL REVIEW LETTERS 2013; 111:133201. [PMID: 24116777 DOI: 10.1103/physrevlett.111.133201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 08/09/2013] [Indexed: 06/02/2023]
Abstract
The trapping lasers of a magneto-optical trap have been used to bring Rb atoms into well defined oriented states. Coupled to recoil-ion-momentum spectroscopy, this provided a unique MOTRIMS setup which was able to probe scattering dynamics, including the coherence features, with unprecedented resolution. The technique was applied to the low-energy charge exchange reactions Na+ + Rb(5p±1)→Na(3p,4s)+Rb+. The measurements revealed detailed features of the collisional interaction which were employed to improve the theoretical description. As such, it was possible to ascertain the validity of the intuitive models used to predict the most likely capture transitions.
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Affiliation(s)
- A Leredde
- LPC Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, F-14070 Caen, France
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Fischer D, Globig D, Goullon J, Grieser M, Hubele R, de Jesus VLB, Kelkar A, LaForge A, Lindenblatt H, Misra D, Najjari B, Schneider K, Schulz M, Sell M, Wang X. Ion-lithium collision dynamics studied with a laser-cooled in-ring target. PHYSICAL REVIEW LETTERS 2012; 109:113202. [PMID: 23005625 DOI: 10.1103/physrevlett.109.113202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Indexed: 06/01/2023]
Abstract
We present a novel experimental tool allowing for kinematically complete studies of break-up processes of laser-cooled atoms. This apparatus, the 'MOTReMi,' is a combination of a magneto-optical trap (MOT) and a reaction microscope (ReMi). Operated in an ion-storage ring, the new setup enables us to study the dynamics in swift ion-atom collisions on an unprecedented level of precision and detail. In the inaugural experiment on collisions with 1.5 MeV/amu O(8+)-Li the pure ionization of the valence electron as well as the ionization-excitation of the lithium target was investigated.
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Affiliation(s)
- D Fischer
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
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Blieck J, Fléchard X, Cassimi A, Gilles H, Girard S, Hennecart D. A new MOTRIMS apparatus for high resolution measurements in ion-atom collisions and trapped atoms studies. ACTA ACUST UNITED AC 2009. [DOI: 10.1088/1742-6596/163/1/012070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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7
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Blieck J, Fléchard X, Cassimi A, Gilles H, Girard S, Hennecart D. A new magneto-optical trap-target recoil ion momentum spectroscopy apparatus for ion-atom collisions and trapped atom studies. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:103102. [PMID: 19044697 DOI: 10.1063/1.2994151] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A new magneto-optical trap-target recoil ion momentum spectroscopy apparatus has been built and tested at the LPC-CAEN. Dedicated to ion-atom collisions studies and excited fraction measurements, the setup combines a projectile ion beam line, a target of cold rubidium atoms provided by a magneto-optical trap (MOT), and a recoil ion momentum spectrometer. In a test experiment using a beam of Na(+) projectiles, we demonstrate its capability to measure, with a very high signal over background ratio, fully differential cross sections in scattering angle, initial state, and final state of the system. We detail, in this work, features that had not been described previously in the literature: an extraction of the recoil ions transverse to the ion beam axis, and a fast switch for the MOT magnetic field. Advantages of transverse versus longitudinal extraction are discussed, and future possibilities for the setup are presented.
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Affiliation(s)
- J Blieck
- LPC Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, Caen 14050, France
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Coutinho LH, Cavasso-Filho RL, Rocha TCR, Homem MGP, Figueira DSL, Fonseca PT, Cruz FC, Naves de Brito A. Relativistic and interchannel coupling effects in photoionization angular distributions by synchrotron spectrocopy of laser cooled atoms. PHYSICAL REVIEW LETTERS 2004; 93:183001. [PMID: 15525159 DOI: 10.1103/physrevlett.93.183001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2003] [Indexed: 05/24/2023]
Abstract
We investigate the angular distribution of photoionization fragments at low photon energies (12-40 eV) in an open shell atom, by synchrotron radiation recoil ion momentum spectroscopy in a laser cooled and trapped sample. For cesium atoms, for which relativistic effects play an important role and the ion recoil is relatively small, we could determine large and rapid changes of the asymmetry parameter beta from two, observed for s electrons outside resonances and far from the Cooper minimum. They can be explained by relativistic effects and interchannel coupling arising from final state configuration mixing.
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Affiliation(s)
- L H Coutinho
- Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas (UNICAMP), Box 6165, CEP 13083-970 Campinas-SP, Brazil
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9
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Flechard X, Nguyen H, Bredy R, Lundeen SR, Stauffer M, Camp HA, Fehrenbach CW, DePaola BD. State selective charge transfer cross sections for Na+ with excited rubidium: a unique diagnostic of the population dynamics of a magneto-optical trap. PHYSICAL REVIEW LETTERS 2003; 91:243005. [PMID: 14683116 DOI: 10.1103/physrevlett.91.243005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2003] [Indexed: 05/24/2023]
Abstract
It is shown how the newly developed technique of magneto-optical-trap recoil-ion momentum spectroscopy can be used to measure the temporal evolution of excited state fraction in such a trap. In this case, the fraction of atoms in a 5p state is measured. The technique can be generalized to allow the measurement of more complicated systems, e.g., a Rb sample having a mixture of 5s, 5p, 4d, and Rydberg states.
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Affiliation(s)
- X Flechard
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
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