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Title: Photodetachment of H{sup -} in a static electric field near an elastic wall

Abstract

The photodetachment cross section of H{sup -} in a static electric field near an elastic wall is investigated based on both a quantum approach and the semiclassical closed-orbit theory. It is found that the distance between the ion and wall is another factor to modulate the cross section of the photodetachment. For an elastic wall perpendicular to the electric field, the detachment spectrum displays an irregular staircase structure, contrasting with the smooth oscillation when only the electric field exists.

Authors:
; ;  [1]
  1. School of Physics and Electronic Information, Wenzhou University, Wenzhou, 325027 (China)
Publication Date:
OSTI Identifier:
20787131
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 73; Journal Issue: 4; Other Information: DOI: 10.1103/PhysRevA.73.043413; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; CROSS SECTIONS; DISTANCE; ELECTRIC FIELDS; ELECTRON DETACHMENT; HYDROGEN IONS 1 MINUS; ORBITS; OSCILLATIONS; SEMICLASSICAL APPROXIMATION; WALLS

Citation Formats

Yang Guangcan, Zheng Yizhuang, and Chi Xianxing. Photodetachment of H{sup -} in a static electric field near an elastic wall. United States: N. p., 2006. Web. doi:10.1103/PHYSREVA.73.0.
Yang Guangcan, Zheng Yizhuang, & Chi Xianxing. Photodetachment of H{sup -} in a static electric field near an elastic wall. United States. doi:10.1103/PHYSREVA.73.0.
Yang Guangcan, Zheng Yizhuang, and Chi Xianxing. Sat . "Photodetachment of H{sup -} in a static electric field near an elastic wall". United States. doi:10.1103/PHYSREVA.73.0.
@article{osti_20787131,
title = {Photodetachment of H{sup -} in a static electric field near an elastic wall},
author = {Yang Guangcan and Zheng Yizhuang and Chi Xianxing},
abstractNote = {The photodetachment cross section of H{sup -} in a static electric field near an elastic wall is investigated based on both a quantum approach and the semiclassical closed-orbit theory. It is found that the distance between the ion and wall is another factor to modulate the cross section of the photodetachment. For an elastic wall perpendicular to the electric field, the detachment spectrum displays an irregular staircase structure, contrasting with the smooth oscillation when only the electric field exists.},
doi = {10.1103/PHYSREVA.73.0},
journal = {Physical Review. A},
number = 4,
volume = 73,
place = {United States},
year = {Sat Apr 15 00:00:00 EDT 2006},
month = {Sat Apr 15 00:00:00 EDT 2006}
}
  • In a recent theoretical study on the photodetachment cross section of H{sup -} in a static electric field near an elastic wall, Yang et al. found significant difference between the result of closed-orbit theory and a quantum approach [Phys. Rev. A 73, 043413 (2006)]. They attributed the difference to the semiclassical approximations in closed-orbit theory. We have examined the application of closed-orbit theory to the same problem and found the disagreement is caused by the incorrectly assigned phases and amplitudes associated with closed-orbits. After the phases and amplitudes are corrected, the closed-orbit theory is shown to be in excellent agreementmore » with the quantum result.« less
  • Standard closed-orbit theory is applied to derive the photodetachment cross section of H{sup -} in the presence of a static electric field. The result agrees with the one derived earlier using a quantum approach involving a momentum-space wave function and stationary-phase approximation. The advantage of the present derivation is the ability to separate the oscillation term and the smooth background term in the photodetachment cross section and to identify the two terms with different physical origins.
  • Theoretical calculations of quantum interference effects occurring in photodetachement of H[sup [minus]] with short-pulse lasers in the presence of a uniform static electric field [Q. Wang and A. F. Starace, Phys. Rev. A 48, R1741 (1993)] are examined in more detail and extended to the case of parallel static electric and magnetic fields. We show that modulation factors characterizing near-threshold cross sections resulting from detachment by relatively long laser pulses may be employed to set the parameters that are most effective for control of detachment cross-section magnitudes with short coherent laser pulses. Use of a static magnetic field to controlmore » detached electron wave-packet motion perpendicular to the static field axis is shown to increase greatly the magnitude of quantum interference effects on the cross sections (from 10% of the field-free cross section in an optimized static electric-field case to 50% in a parallel static electric and magnetic-field case). Theoretical dependence of calculated cross sections on laser pulse lengths, time delays, relative phases, frequencies, and classical electron orbit times are presented and discussed in detail.« less
  • We present a detailed quantum mechanical treatment of the photodetachment of H{sup -} by a short laser pulse in the presence of crossed static electric and magnetic fields. An exact analytic formula is presented for the final state electron wave function (describing an electron in both static electric and magnetic fields and a short laser pulse of arbitrary intensity). In the limit of a weak laser pulse, final state electron wave packet motion is examined and related to the closed classical electron orbits in crossed static fields predicted by Peters and Delos [Phys. Rev. A 47, 3020 (1993)]. Owing tomore » these closed orbit trajectories, we show that the detachment probability can be modulated, depending on the time delay between two laser pulses and their relative phase, thereby providing a means to partially control the photodetachment process. In the limit of a long, weak pulse (i.e., a monochromatic radiation field) our results reduce to those of others; however, for this case we analyze the photodetachment cross section numerically over a much larger range of electron kinetic energy (i.e., up to 500 cm{sup -1}) than in previous studies and relate the detailed structures both analytically and numerically to the above-mentioned, closed classical periodic orbits.« less
  • We calculated near-threshold photodetachment cross sections for Cs{sup -} in the presence of a dc electric field using three different approaches: the frame-transformation method with and without rescattering effects and the Kirchhoff-integral approach. Radial wave functions for the electronic motion were obtained using the Pauli equation method with a model potential describing the effective electron-atom interaction. Our results demonstrate the inadequacy of the frame-transformation method in the {sup 3}P resonance region even for weak fields (E<10 kV/cm). We show that the triplet and singlet contributions to the total cross section can be manipulated by varying the external electric field. Thismore » can enhance spin-orbit effects in the photodetachment process and create more favorable conditions in the experiment for the observation of the lowest {sup 3}P resonance in Cs{sup -}.« less