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Neumark DM. Spectroscopy of Radicals, Clusters, and Transition States Using Slow Electron Velocity-Map Imaging of Cryogenically Cooled Anions. J Phys Chem A 2023; 127:4207-4223. [PMID: 37094039 DOI: 10.1021/acs.jpca.3c01537] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Slow electron velocity-map imaging of cryogenically cooled anions (cryo-SEVI) is a high-resolution variant of anion photoelectron spectroscopy that has been applied with considerable success over the years to the study of radicals, size-selected clusters, and transition states for unimolecular and bimolecular reactions. Cryo-SEVI retains the versatility of conventional anion photoelectron spectroscopy while offering sub-meV resolution, thereby enabling the resolution of vibrational structure in the photoelectron spectra of complex anions. This Feature Article describes recent experiments in our laboratory using cryo-SEVI, including a new research direction in which anions are vibrationally pre-excited with an infrared laser pulse prior to photodetachment.
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Affiliation(s)
- Daniel M Neumark
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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2
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Wang DH, Sun XY, Shi T. Photoionization microscopy of the Rydberg Rb atom under a continuous infrared radiation laser field. CAN J CHEM 2020. [DOI: 10.1139/cjc-2019-0267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The photoionization microscopy of the Rydberg Rb atom exposed to a continuous infrared radiation laser field is investigated based on the semiclassical open orbit theory. In contrast to the photoionization of the Rydberg hydrogen atom, the ionic core-scattering effect plays an important role in the photoionization of the Rb atom. Due to the core-scattering effect and the laser field, the electron trajectories become chaotic. A huge number of ionization trajectories from the ionic source to the detector plane appear, which makes the oscillatory pattern in the electron probability distribution become much more complicated. The ρ–θ curve on the detector plane exhibits a self-similar fractal structure for the ionization trajectories of the Rydberg Rb atom in the laser field. Due to constructive and destructive quantum interference of different electron trajectories, a series of concentric rings appear in the photoionization microscopy interference patterns on the detector plane. The electron probability density distributions on the detector are found to be changed sensitively with the scaled electron energy and the laser wavelength. Even as the detector plane is located at a macroscopic distance from the photoionization source, the photoionization microscopy interference patterns can be observed clearly. These calculations may provide a valuable contribution to the actual experimental study of the photoionization microscopy of non-hydrogenic Rydberg atom in the laser field.
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Affiliation(s)
- De-Hua Wang
- School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264025, China
- School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264025, China
| | - Xin-Yue Sun
- School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264025, China
- School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264025, China
| | - Tong Shi
- School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264025, China
- School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264025, China
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3
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Rozenman GG, Zimmermann M, Efremov MA, Schleich WP, Shemer L, Arie A. Amplitude and Phase of Wave Packets in a Linear Potential. PHYSICAL REVIEW LETTERS 2019; 122:124302. [PMID: 30978087 DOI: 10.1103/physrevlett.122.124302] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Indexed: 06/09/2023]
Abstract
We theoretically study and successfully observe the evolution of Gaussian and Airy surface gravity water wave packets propagating in an effective linear potential. This potential results from a homogeneous and time-dependent flow created by a computer-controlled water pump. For both wave packets we measure the amplitudes and the cubic phases appearing due to the linear potential. Furthermore, we demonstrate that the self-acceleration of the Airy surface gravity water wave packets can be completely canceled by a linear potential.
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Affiliation(s)
- Georgi Gary Rozenman
- Raymond and Beverly Sackler School of Physics & Astronomy, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
- School of Electrical Engineering, Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel
| | - Matthias Zimmermann
- Institut für Quantenphysik and Center for Integrated Quantum Science and Technology (IQST), Universität Ulm, 89081 Ulm, Germany
| | - Maxim A Efremov
- Institut für Quantenphysik and Center for Integrated Quantum Science and Technology (IQST), Universität Ulm, 89081 Ulm, Germany
| | - Wolfgang P Schleich
- Institut für Quantenphysik and Center for Integrated Quantum Science and Technology (IQST), Universität Ulm, 89081 Ulm, Germany
- Hagler Institute for Advanced Study at Texas A & M University, Texas A & M AgriLife Research, Institute for Quantum Science and Engineering (IQSE), and Department of Physics and Astronomy, Texas A & M University, College Station, Texas 77843-4242, USA
| | - Lev Shemer
- School of Mechanical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ady Arie
- School of Electrical Engineering, Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel
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4
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Pursehouse J, Murray AJ, Wätzel J, Berakdar J. Dynamic Double-Slit Experiment in a Single Atom. PHYSICAL REVIEW LETTERS 2019; 122:053204. [PMID: 30822012 DOI: 10.1103/physrevlett.122.053204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/21/2018] [Indexed: 06/09/2023]
Abstract
A single-atom "double-slit" experiment is realized by photoionizing rubidium atoms using two independent low power lasers. The photoelectron wave of well-defined energy recedes to the continuum either from the 5P or 6P states in the same atom, resulting in two-path interference imaged in the far field using a photoelectron detector. Even though the lasers are independent and not phase locked, the transitions within the atom impart the phase relationship necessary for interference. The experiment is designed so that either 5P or 6P states are excited by one laser, before ionization by the second beam. The measurement cannot determine which excitation path is taken, resulting in interference in wave-vector space analogous to Young's double-slit studies. As the lasers are tunable in both frequency and intensity, the individual excitation-ionization pathways can be varied, allowing dynamic control of the interference term. Since the electron wave recedes in the Coulomb potential of the residual ion, a quantum model is used to capture the dynamics. Excellent agreement is found between theory and experiment.
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Affiliation(s)
- James Pursehouse
- Photon Science Institute, School of Physics & Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Andrew James Murray
- Photon Science Institute, School of Physics & Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Jonas Wätzel
- Martin-Luther-Universität Halle-Wittenberg, Institute of Physics, 06099 Halle/Saale, Germany
| | - Jamal Berakdar
- Martin-Luther-Universität Halle-Wittenberg, Institute of Physics, 06099 Halle/Saale, Germany
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5
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Abstract
Slow photoelectron velocity-map imaging spectroscopy of cryogenically cooled anions (cryo-SEVI) is a powerful technique for elucidating the vibrational and electronic structure of neutral radicals, clusters, and reaction transition states. SEVI is a high-resolution variant of anion photoelectron spectroscopy based on photoelectron imaging that yields spectra with energy resolution as high as 1-2 cm-1. The preparation of cryogenically cold anions largely eliminates hot bands and dramatically narrows the rotational envelopes of spectral features, enabling the acquisition of well-resolved photoelectron spectra for complex and spectroscopically challenging species. We review the basis and history of the SEVI method, including recent experimental developments that have improved its resolution and versatility. We then survey recent SEVI studies to demonstrate the utility of this technique in the spectroscopy of aromatic radicals, metal and metal oxide clusters, nonadiabatic interactions between excited states of small molecules, and transition states of benchmark bimolecular reactions.
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Affiliation(s)
- Marissa L Weichman
- Department of Chemistry, University of California, Berkeley, California 94720, USA; , .,Current affiliation: JILA, National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Daniel M Neumark
- Department of Chemistry, University of California, Berkeley, California 94720, USA; , .,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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6
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Chandler DW, Houston PL, Parker DH. Perspective: Advanced particle imaging. J Chem Phys 2017; 147:013601. [PMID: 28688442 PMCID: PMC5648558 DOI: 10.1063/1.4983623] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 04/18/2017] [Indexed: 11/14/2022] Open
Abstract
Since the first ion imaging experiment [D. W. Chandler and P. L. Houston, J. Chem. Phys. 87, 1445-1447 (1987)], demonstrating the capability of collecting an image of the photofragments from a unimolecular dissociation event and analyzing that image to obtain the three-dimensional velocity distribution of the fragments, the efficacy and breadth of application of the ion imaging technique have continued to improve and grow. With the addition of velocity mapping, ion/electron centroiding, and slice imaging techniques, the versatility and velocity resolution have been unmatched. Recent improvements in molecular beam, laser, sensor, and computer technology are allowing even more advanced particle imaging experiments, and eventually we can expect multi-mass imaging with co-variance and full coincidence capability on a single shot basis with repetition rates in the kilohertz range. This progress should further enable "complete" experiments-the holy grail of molecular dynamics-where all quantum numbers of reactants and products of a bimolecular scattering event are fully determined and even under our control.
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Affiliation(s)
- David W Chandler
- Sandia National Laboratories, Combustion Research Facility, Livermore, California 94550, USA
| | - Paul L Houston
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA
| | - David H Parker
- Department of Laser and Molecular Physics, Radboud University of Nijmegen, Nijmegen, Netherlands
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7
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Chen X, Luo Z, Li J, Ning C. Accurate Electron Affinity of Iron and Fine Structures of Negative Iron ions. Sci Rep 2016; 6:24996. [PMID: 27138292 PMCID: PMC4853736 DOI: 10.1038/srep24996] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 04/08/2016] [Indexed: 11/12/2022] Open
Abstract
Ionization potential (IP) is defined as the amount of energy required to remove the most loosely bound electron of an atom, while electron affinity (EA) is defined as the amount of energy released when an electron is attached to a neutral atom. Both IP and EA are critical for understanding chemical properties of an element. In contrast to accurate IPs and structures of neutral atoms, EAs and structures of negative ions are relatively unexplored, especially for the transition metal anions. Here, we report the accurate EA value of Fe and fine structures of Fe(-) using the slow electron velocity imaging method. These measurements yield a very accurate EA value of Fe, 1235.93(28) cm(-1) or 153.236(34) meV. The fine structures of Fe(-) were also successfully resolved. The present work provides a reliable benchmark for theoretical calculations, and also paves the way for improving the EA measurements of other transition metal atoms to the sub cm(-1) accuracy.
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Affiliation(s)
- Xiaolin Chen
- Department of Physics, State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 10084, China
| | - Zhihong Luo
- Department of Physics, State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 10084, China
| | - Jiaming Li
- Department of Physics, State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 10084, China
| | - Chuangang Ning
- Department of Physics, State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 10084, China
- Collaborative Innovation Center of Quantum Matter, Beijing, China
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8
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Stodolna AS, Lépine F, Bergeman T, Robicheaux F, Gijsbertsen A, Jungmann JH, Bordas C, Vrakking MJJ. Visualizing the coupling between red and blue stark states using photoionization microscopy. PHYSICAL REVIEW LETTERS 2014; 113:103002. [PMID: 25238354 DOI: 10.1103/physrevlett.113.103002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Indexed: 06/03/2023]
Abstract
In nonhydrogenic atoms in a dc electric field, the finite size of the ionic core introduces a coupling between quasibound Stark states that leads to avoided crossings between states that would otherwise cross. Near an avoided crossing, the interacting states may have decay amplitudes that cancel each other, decoupling one of the states from the ionization continuum. This well-known interference narrowing effect, observed as a strongly electric field-dependent decrease in the ionization rate, was previously observed in several atoms. Here we use photoionization microscopy to visualize interference narrowing in helium atoms, thereby explicitly revealing the mechanism by which Stark states decay. The interference narrowing allows measurements of the nodal patterns of red Stark states, which are otherwise not observable due to their intrinsic short lifetime.
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Affiliation(s)
- A S Stodolna
- FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - F Lépine
- Institut Lumiére Matiére, Université Lyon 1, CNRS, UMR 5306, 10 rue Ada Byron, 69622 Villeurbanne Cedex, France
| | - T Bergeman
- Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - F Robicheaux
- Department of Physics, Purdue University, West Lafayette, Indiana 47907, USA
| | - A Gijsbertsen
- FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - J H Jungmann
- FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - C Bordas
- Institut Lumiére Matiére, Université Lyon 1, CNRS, UMR 5306, 10 rue Ada Byron, 69622 Villeurbanne Cedex, France
| | - M J J Vrakking
- FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands and Max-Born-Institut, Max Born Straße 2A, D-12489 Berlin, Germany
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9
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HANEEF MUHAMMAD, ARIF SUNEELA, AKBAR JEHAN, SHAH NASRULLAH, ZAHIR MUHAMMAD. THE INVESTIGATION OF NON-OSCILLATING STRUCTURE OF THE PHOTODETACHMENT CROSS SECTION OF MOLECULAR ANION USING TRADITIONAL THEORETICAL IMAGING METHOD. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2013. [DOI: 10.1142/s0219633613500417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Using traditional theoretical imaging method, we predict invisible oscillations in the photodetachment cross section of [Formula: see text] near a thin soft surface. A laser which is polarized parallel to the surface is used to knock off electron from [Formula: see text]. Analytical expressions are derived for detached electron flux and photodetachment cross section. The results depend on the inter ion surface distance and separation of the atomic centers of the molecular anion. It is found that the surface strongly affects the detached electron flux and the photodetachment cross section. Unlike the detached electron flux the cross section displays non-oscillating structure. The non-oscillating structure is attributed to the parallel orientation of the laser polarization direction with the thin elastic surface.
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Affiliation(s)
- MUHAMMAD HANEEF
- Lab of Atom and Quantum Interference, Department of Physics, Hazara University, Garden Campus, Mansehra, Pakistan
| | - SUNEELA ARIF
- Lab of Atom and Quantum Interference, Department of Physics, Hazara University, Garden Campus, Mansehra, Pakistan
| | - JEHAN AKBAR
- Lab of Atom and Quantum Interference, Department of Physics, Hazara University, Garden Campus, Mansehra, Pakistan
| | - NASRULLAH SHAH
- Department of Chemistry, Abdul Wali Khan University, Mardan, Pakistan
| | - MUHAMMAD ZAHIR
- Department of Statistics, University of Peshawar, Pakistan
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10
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Stodolna AS, Rouzée A, Lépine F, Cohen S, Robicheaux F, Gijsbertsen A, Jungmann JH, Bordas C, Vrakking MJJ. Hydrogen atoms under magnification: direct observation of the nodal structure of Stark states. PHYSICAL REVIEW LETTERS 2013; 110:213001. [PMID: 23745864 DOI: 10.1103/physrevlett.110.213001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 03/13/2013] [Indexed: 05/12/2023]
Abstract
To describe the microscopic properties of matter, quantum mechanics uses wave functions, whose structure and time dependence is governed by the Schrödinger equation. In atoms the charge distributions described by the wave function are rarely observed. The hydrogen atom is unique, since it only has one electron and, in a dc electric field, the Stark Hamiltonian is exactly separable in terms of parabolic coordinates (η, ξ, φ). As a result, the microscopic wave function along the ξ coordinate that exists in the vicinity of the atom, and the projection of the continuum wave function measured at a macroscopic distance, share the same nodal structure. In this Letter, we report photoionization microscopy experiments where this nodal structure is directly observed. The experiments provide a validation of theoretical predictions that have been made over the last three decades.
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Affiliation(s)
- A S Stodolna
- FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
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11
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Cohen S, Harb MM, Ollagnier A, Robicheaux F, Vrakking MJJ, Barillot T, Lépine F, Bordas C. Wave function microscopy of quasibound atomic states. PHYSICAL REVIEW LETTERS 2013; 110:183001. [PMID: 23683194 DOI: 10.1103/physrevlett.110.183001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 11/30/2012] [Indexed: 06/02/2023]
Abstract
In the 1980s Demkov, Kondratovich, and Ostrovsky and Kondratovich and Ostrovsky proposed an experiment based on the projection of slow electrons emitted by a photoionized atom onto a position-sensitive detector. In the case of resonant excitation, they predicted that the spatial electron distribution on the detector should represent nothing else but a magnified image of the projection of a quasibound electronic state. By exciting lithium atoms in the presence of a static electric field, we present in this Letter the first experimental photoionization wave function microscopy images where signatures of quasibound states are evident. Characteristic resonant features, such as (i) the abrupt change of the number of wave function nodes across a resonance and (ii) the broadening of the outer ring of the image (associated with tunneling ionization), are observed and interpreted via wave packet propagation simulations and recently proposed resonance tunneling mechanisms. The electron spatial distribution measured by our microscope is a direct macroscopic image of the projection of the microscopic squared modulus of the electron wave that is quasibound to the atom and constitutes the first experimental realization of the experiment proposed 30 years ago.
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Affiliation(s)
- S Cohen
- Physics Department, Atomic and Molecular Physics Laboratory, University of Ioannina, 45110 Ioannina, Greece
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12
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Cavanagh SJ, Gibson ST, Lewis BR. High-resolution photoelectron spectroscopy of linear ← bent polyatomic photodetachment transitions: The electron affinity of CS2. J Chem Phys 2012; 137:144304. [DOI: 10.1063/1.4757726] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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13
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Cauët E, Carette T, Lauzin C, Li JG, Loreau J, Delsaut M, Nazé C, Verdebout S, Vranckx S, Godefroid M, Liévin J, Vaeck N. From atoms to biomolecules: a fruitful perspective. Theor Chem Acc 2012. [DOI: 10.1007/s00214-012-1254-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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14
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Diehl C, Wendt K, Lindahl AO, Andersson P, Hanstorp D. Ion optical design of a collinear laser-negative ion beam apparatus. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:053302. [PMID: 21639495 DOI: 10.1063/1.3587617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
An apparatus for photodetachment studies on atomic and molecular negative ions of medium up to heavy mass (M ≃ 500) has been designed and constructed. Laser and ion beams are merged in the apparatus in a collinear geometry and atoms, neutral molecules and negative ions are detected in the forward direction. The ion optical design and the components used to optimize the mass resolution and the transmission through the extended field-free interaction region are described. A 90° sector field magnet with 50 cm bending radius in combination with two slits is used for mass dispersion providing a resolution of M∕ΔM≅800 for molecular ions and M∕ΔM≅400 for atomic ions. The difference in mass resolution for atomic and molecular ions is attributed to different energy distributions of the sputtered ions. With 1 mm slits, transmission from the source through the interaction region to the final ion detector was determined to be about 0.14%.
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Affiliation(s)
- C Diehl
- Institut für Physik, Johannes Gutenberg-Universität, Mainz, D-55099 Mainz, Germany
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15
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Neumark DM. Slow electron velocity-map imaging of negative ions: applications to spectroscopy and dynamics. J Phys Chem A 2009; 112:13287-301. [PMID: 19032143 DOI: 10.1021/jp807182q] [Citation(s) in RCA: 186] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Anion photoelectron spectroscopy (PES) has become one of the most versatile techniques in chemical physics. This article briefly reviews the history of anion PES and some of its applications. It describes efforts to improve the resolution of this technique, including anion zero electron kinetic energy (ZEKE) and the recently developed method of slow electron velocity-map imaging (SEVI). Applications of SEVI to studies of vibronic coupling in open-shell systems and the spectroscopy of prereactive van der Waals complexes are then discussed.
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Affiliation(s)
- Daniel M Neumark
- Department of Chemistry, University of California, Berkeley, and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
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16
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17
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Bracher C, Delos JB. Motion of an electron from a point source in parallel electric and magnetic fields. PHYSICAL REVIEW LETTERS 2006; 96:100404. [PMID: 16605714 DOI: 10.1103/physrevlett.96.100404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2005] [Indexed: 05/08/2023]
Abstract
Negative ions undergoing near-threshold photodetachment in a weak laser field provide an almost pointlike, isotropic source of low-energy electrons. External fields exert forces on the emitted coherent electron wave and direct its motion. Here, we examine the spatial distribution of photodetached electrons in uniform, parallel electric and magnetic fields. The interplay of the electric and magnetic forces leads to a surprising intricate shape of the refracted electron wave, and multiple interfering trajectories generate complex fringe patterns in the matter wave. The exact quantum solution is best understood in terms of the classical electron motion.
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Affiliation(s)
- Christian Bracher
- Physics Department, The College of William and Mary, Williamsburg, Virginia 23187-8795, USA.
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18
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Goldfarb F, Drag C, Chaibi W, Kröger S, Blondel C, Delsart C. Photodetachment microscopy of the P, Q, and R branches of the OH−(v=0) to OH(v=0) detachment threshold. J Chem Phys 2005; 122:14308. [PMID: 15638660 DOI: 10.1063/1.1824904] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
A photodetachment experiment is performed on the v=0-->v=0 OH(-) detachment threshold. The weak O and S branches provide a signal strong enough to make amplitude measurements on all five O, P, Q, R, and S branches possible, which are used to fix the formulas for their relative intensities. Photodetachment microscopy is applied to 15 different thresholds of the P, Q, and R branches. The quantitative analysis of the interference patterns obtained does not show any effect of the dipole moment of OH, but yields a new measurement of the rotational parameters of OH(-)(v=0) and of the electron affinity of the molecule. The new recommended value for the electron affinity of (16)O(1)H is 14 740.982(7) cm(-1) or 1.827 648 7(11) eV.
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Affiliation(s)
- Fabienne Goldfarb
- Laboratoire Aimé-Cotton, Centre National de la Recherche Scientifique, Bâtiment 505, F-91405 Orsay cedex, France
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19
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Delsart C, Goldfarb F, Blondel C. Molecular photodetachment microscopy. PHYSICAL REVIEW LETTERS 2002; 89:183002. [PMID: 12398595 DOI: 10.1103/physrevlett.89.183002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2002] [Indexed: 05/24/2023]
Abstract
The photodetachment microscopy technique, which was originally used with atomic negative ions, is now applied to a molecular anion. The interferograms of several rotational thresholds corresponding to transitions from OH- X (1)Sigma(+) v=0 states to OH X (2)Pi(3/2,1/2) v=0 states have been recorded. No effect due to the 1/r(2) dipolar potential of the neutral molecule appears. Using a double-pass scheme of the laser on the negative ion beam, we measure the energy of the first few detachment thresholds with improved accuracy. The new recommended value of the electron affinity of 16OH is 14,740.996(13) cm(-1), or 1.827 650 3(17) eV.
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Affiliation(s)
- Christian Delsart
- Laboratoire Aimé-Cotton, Centre National de la Recherche Scientifique, Bâtiment 505, F-91405 Orsay Cedex, France
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20
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Nicole C, Offerhaus HL, Vrakking MJJ, Lépine F, Bordas C. Photoionization microscopy. PHYSICAL REVIEW LETTERS 2002; 88:133001. [PMID: 11955092 DOI: 10.1103/physrevlett.88.133001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2001] [Indexed: 05/23/2023]
Abstract
We present the first experimental results of a technique called photoionization microscopy. Photoelectrons ejected in threshold photoionization of Xe are detected in a velocity map imaging apparatus, and interferences between various trajectories by which the electron moves from the atom to the detector are observed. The structure of the interference pattern, which contains the transverse component of the electronic wave function, evolves smoothly with the excess energy above the saddle point. The main observed features are interpreted within the framework of the semiclassical approximation.
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Affiliation(s)
- C Nicole
- FOM Instituut voor Atoom en Molecuul Fysica (AMOLF), Kruislaan 407, 1098 SJ, Amsterdam, The Netherlands
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21
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Deyerl HJ, Alconcel LS, Continetti RE. Photodetachment Imaging Studies of the Electron Affinity of CF3. J Phys Chem A 2000. [DOI: 10.1021/jp003137k] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Hans-Jürgen Deyerl
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0314
| | - Leah S. Alconcel
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0314
| | - Robert E. Continetti
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0314
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Nicole C, Sluimer I, Rosca-Pruna F, Warntjes M, Vrakking M, Bordas C, Texier F, Robicheaux F. Slow photoelectron imaging. PHYSICAL REVIEW LETTERS 2000; 85:4024-4027. [PMID: 11056615 DOI: 10.1103/physrevlett.85.4024] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2000] [Indexed: 05/23/2023]
Abstract
Experiments are reported on the detection of slow photoelectrons resulting from the photoionization of Xe atoms in a dc electric field by electron imaging. In the far-field photoelectron velocity distributions we can distinguish between direct and indirect ionization processes (involving long range Coulomb interactions with the Xe+ ion). Also, a new modulation of the velocity distribution is observed which cannot be explained by previously discussed mechanisms. Classical and quantum mechanical calculations are presented to support the interpretations.
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Affiliation(s)
- C Nicole
- FOM Institute for Atomic and Molecular Physics (AMOLF), Kruislaan 407, 1098 SJ Amsterdam, The Netherlands
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Winterhalter J, Maier D, Honerkamp J, Schyja V, Helm H. Imaging of charged atomic reaction products: Inversion by a two-dimensional regularization method. J Chem Phys 1999. [DOI: 10.1063/1.479060] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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