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Sixt T, Chung T, Stienkemeier F, Dulitz K. Symmetry Dependence of the Continuum Coupling in the Chemi-ionization of Li(2 2S 1/2) by He(2 3S 1, 2 3P J). J Phys Chem A 2023; 127:4407-4414. [PMID: 37184430 DOI: 10.1021/acs.jpca.3c00431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
In the literature, the chemi-ionization of Li in the 22S1/2 ground level by He in a metastable state is typically described as an electron transfer process in which an electron from the 2s orbital of Li is transferred to the 1s orbital of He while an electron from the 2s orbital of He is ejected. Therefore, one would not assume that the orbital of the valence electron of He strongly influences the coupling strength of the collision complex to the ionization continuum. However, we observe that the chemi-ionization rate is decreased when He is laser-excited from the metastable 23S1 level to the 23PJ level (with J = 0, 1, 2). A semiclassical treatment of the reaction dynamics reveals a strong dependence of the ionization rate on the reaction-channel-specific ionization width functions to which the observed decrease of the rate coefficients can be related to. The results are relevant for the improved understanding and control of chemi-ionization processes in merged beams and in traps.
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Affiliation(s)
- Tobias Sixt
- Institute of Physics, University of Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - Taewon Chung
- Institute of Physics, University of Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - Frank Stienkemeier
- Institute of Physics, University of Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - Katrin Dulitz
- Institute of Physics, University of Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, 6020 Innsbruck, Austria
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Sixt T, Stienkemeier F, Dulitz K. Spin-state-controlled chemi-ionization reactions between metastable helium atoms and ground-state lithium atoms. J Chem Phys 2022; 156:114306. [DOI: 10.1063/5.0083842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We demonstrate the control of 4He(23S1)–7Li(22S1/2) chemi-ionization reactions by all-optical electron-spin-state preparation of both atomic species prior to the collision process. Our results demonstrate that chemi-ionization is strongly suppressed (enhanced) for non-spin-conserving (spin-conserving) collisions at thermal energies. These findings are in good agreement with a model based on spin angular momentum coupling of the prepared atomic states to the quasi-molecular states. Small deviations from the model indicate the contribution of the 4Σ+ channel to the reaction rate, which is in violation of spin conservation.
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Affiliation(s)
- Tobias Sixt
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Frank Stienkemeier
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Katrin Dulitz
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
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Ben Ltaief L, Shcherbinin M, Mandal S, Krishnan SR, LaForge AC, Richter R, Turchini S, Zema N, Pfeifer T, Fasshauer E, Sisourat N, Mudrich M. Charge Exchange Dominates Long-Range Interatomic Coulombic Decay of Excited Metal-Doped Helium Nanodroplets. J Phys Chem Lett 2019; 10:6904-6909. [PMID: 31625747 DOI: 10.1021/acs.jpclett.9b02726] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Atoms and molecules attached to rare-gas clusters are ionized by an interatomic autoionization process traditionally termed "Penning ionization" when the host cluster is resonantly excited. Here we analyze this process in the light of the interatomic Coulombic decay (ICD) mechanism, which usually contains a contribution from charge exchange at a short interatomic distance and one from virtual photon transfer at a large interatomic distance. For helium (He) nanodroplets doped with alkali metal atoms (Li, Rb), we show that long-range and short-range contributions to the interatomic autoionization can be clearly distinguished by detecting electrons and ions in coincidence. Surprisingly, ab initio calculations show that even for alkali metal atoms floating in dimples at a large distance from the nanodroplet surface, autoionization is largely dominated by charge-exchange ICD. Furthermore, the measured electron spectra manifest the ultrafast internal relaxation of the droplet mainly into the 1s2s1S state and partially into the metastable 1s2s3S state.
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Affiliation(s)
- L Ben Ltaief
- Department of Physics and Astronomy , Aarhus University , 8000 Aarhus C , Denmark
| | - M Shcherbinin
- Department of Physics and Astronomy , Aarhus University , 8000 Aarhus C , Denmark
| | - S Mandal
- Indian Institute of Science Education and Research , Pune 411008 , India
| | - S R Krishnan
- Department of Physics , Indian Institute of Technology , Madras, Chennai 600 036 , India
| | - A C LaForge
- Department of Physics , University of Connecticut , Storrs , Connecticut 06269 , United States
| | - R Richter
- Elettra-Sincrotrone Trieste , Basovizza, 34149 Trieste , Italy
| | - S Turchini
- Istituto Struttura della Materia-CNR (ISM-CNR) , 00133 Roma , Italy
| | - N Zema
- Istituto Struttura della Materia-CNR (ISM-CNR) , 00133 Roma , Italy
| | - T Pfeifer
- Max-Planck-Institut für Kernphysik , 69117 Heidelberg , Germany
| | - E Fasshauer
- Department of Physics and Astronomy , Aarhus University , 8000 Aarhus C , Denmark
| | - N Sisourat
- Sorbonne Université, CNRS , Laboratoire de Chimie Physique Matière et Rayonnement, UMR 7614 , F-75005 Paris , France
| | - M Mudrich
- Department of Physics and Astronomy , Aarhus University , 8000 Aarhus C , Denmark
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Grzesiak J, Momose T, Stienkemeier F, Mudrich M, Dulitz K. Penning collisions between supersonically expanded metastable He atoms and laser-cooled Li atoms. J Chem Phys 2019; 150:034201. [DOI: 10.1063/1.5063709] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Jonas Grzesiak
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Takamasa Momose
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Frank Stienkemeier
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Marcel Mudrich
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Katrin Dulitz
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
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Movre M, Thiel L, Meyer W. Theoretical investigation of the autoionization process in molecular collision complexes: He*(2 3S)+Li(2 2S)→He+Li++e−. J Chem Phys 2000. [DOI: 10.1063/1.481935] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Movre M, Meyer W. Theoretical investigation of the autoionization process in molecular collision complexes: Computational methods and applications to He*(23S)+H(12S). J Chem Phys 1997. [DOI: 10.1063/1.473735] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Böttcher A, Morgante A, Grobecker R, Greber T, Ertl G. Singlet-to-triplet conversion of metastable He atoms at alkali-metal overlayers. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 49:10607-10612. [PMID: 10009887 DOI: 10.1103/physrevb.49.10607] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Merz A, Ruf M, Hotop H. Autoionization dynamics of excited collision systems: Angular dependence of the electron and ion energy spectra for He*(2(3)S)+H. PHYSICAL REVIEW LETTERS 1992; 69:3467-3470. [PMID: 10046829 DOI: 10.1103/physrevlett.69.3467] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Khan A, Siddiqui HR, Siska PE. Angle‐energy distributions of Penning ions in crossed molecular beams. II. Effect of Penning electron recoil in Ne*(3s 3P2)+H,D→Ne+H+,D++e−. J Chem Phys 1991. [DOI: 10.1063/1.460842] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Yencha AJ, Ruf MW, Hotop H. Penning ionization and photoionization electron spectrometry of hydrogen bromide. ACTA ACUST UNITED AC 1991. [DOI: 10.1007/bf01425590] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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M�ller MW, Merz A, Ruf MW, Hotop H, Meyer W, Movre M. Experimental and theoretical studies of the Bi-excited collision systems He*(23 S) + He*(23 S, 21 S) at thermal and subthermal kinetic energies. ACTA ACUST UNITED AC 1991. [DOI: 10.1007/bf01425589] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Schohl S, M�ller MW, Meijer HAJ, Ruf MW, Hotop H, Morgner H. The state dependence of the interaction of metastable rare gas atoms Rg*(ms3 P 2,3 P 0) (Rg=Ne, Ar, Kr, Xe) with ground state sodium atoms. ACTA ACUST UNITED AC 1990. [DOI: 10.1007/bf01437526] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Morgner H. The validity of the local approximation in Penning ionization as studied by model calculations. Chem Phys 1990. [DOI: 10.1016/0301-0104(90)89118-a] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Substantial angular dependence of the electron energy spectra for attractive penning ionization systems: He(23S, 21S)+Li(22S). Chem Phys Lett 1989. [DOI: 10.1016/0009-2614(89)87614-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Padial NT, Cohen JS, Martin RL, Lane NF. Theoretical Penning electron-energy distributions for alkali-metal atoms: He(2 1,3S) collisions with sodium and potassium. PHYSICAL REVIEW. A, GENERAL PHYSICS 1989; 40:117-124. [PMID: 9901875 DOI: 10.1103/physreva.40.117] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Padial NT, Martin RL, Cohen JS, Lane NF. Theoretical investigation of the hypothesized crossing between the Penning and atomic autoionizing states of He+K. PHYSICAL REVIEW. A, GENERAL PHYSICS 1989; 39:2715-2717. [PMID: 9901546 DOI: 10.1103/physreva.39.2715] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Bregel T, Yencha AJ, Ruf MW, Waibel H, Hotop H. Detailed electron spectrometric study of the ionization of H2 by He* (21 S, 23 S). ACTA ACUST UNITED AC 1989. [DOI: 10.1007/bf01437343] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kraft T, Bregel T, Ganz J, Harth K, Ruf MW, Hotop H. Accurate comparison of Hel, NeI photoionization and He(23, 1 S), Ne(3s 3 P s,3 P 0) penning ionization of argon atoms and dimers. ACTA ACUST UNITED AC 1988. [DOI: 10.1007/bf01425766] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Baum G, Raith W, Steidl H. Production of a spin-polarized, metastable He(23 S) beam for studies in atomic and surface physics. ACTA ACUST UNITED AC 1988. [DOI: 10.1007/bf01384851] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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22
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Simon W, Yencha AJ, Ruf MW, Hotop H. On the determination of HCl+ (A,v?) vibrational populations from HCl+ (A?X) fluorescence spectra: direct comparison between photoionization and penning ionization. ACTA ACUST UNITED AC 1988. [DOI: 10.1007/bf01384526] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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23
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Müller MW, Bussert W, Ruf M, Hotop H, Meyer W. New oscillatory structure in electron energy spectra from autoionizing quasi-molecules: Subthermal collisions of He(2(3)S) atoms with He(2(1)S,2(3)S) atoms. PHYSICAL REVIEW LETTERS 1987; 59:2279-2282. [PMID: 10035502 DOI: 10.1103/physrevlett.59.2279] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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