Theory of xray absorption by laserdressed atoms
Abstract
An ab initio theory is devised for the xray photoabsorption cross section of atoms in the field of a moderately intense optical laser (800 nm, 10{sup 13} W/cm{sup 2}). The laser dresses the coreexcited atomic states, which introduces a dependence of the cross section on the angle between the polarization vectors of the two linearly polarized radiation sources. We use the HartreeFockSlater approximation to describe the atomic manyparticle problem in conjunction with a nonrelativistic quantumelectrodynamic approach to treat the photonelectron interaction. The continuum wave functions of ejected electrons are treated with a complex absorbing potential that is derived from smooth exterior complex scaling. The solution to the twocolor (xray plus laser) problem is discussed in terms of a direct diagonalization of the complex symmetric matrix representation of the Hamiltonian. Alternative treatments with timeindependent and timedependent nonHermitian perturbation theories are presented that exploit the weak interaction strength between x rays and atoms. We apply the theory to study the photoabsorption cross section of krypton atoms near the K edge. A pronounced modification of the cross section is found in the presence of the optical laser.
 Authors:
 Argonne National Laboratory, Argonne, Illinois 60439 (United States)
 Publication Date:
 OSTI Identifier:
 20982360
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevA.75.033412; (c) 2007 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; ABSORPTION; CROSS SECTIONS; ELECTRONS; EXCITED STATES; HAMILTONIANS; HARTREEFOCK METHOD; KRYPTON; LASER RADIATION; MATHEMATICAL SOLUTIONS; MODIFICATIONS; PERTURBATION THEORY; PHOTONATOM COLLISIONS; PHOTONELECTRON INTERACTIONS; QUANTUM ELECTRODYNAMICS; RADIATION SOURCES; TIME DEPENDENCE; WAVE FUNCTIONS; WEAK INTERACTIONS; X RADIATION; XRAY SPECTRA
Citation Formats
Buth, Christian, and Santra, Robin. Theory of xray absorption by laserdressed atoms. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVA.75.033412.
Buth, Christian, & Santra, Robin. Theory of xray absorption by laserdressed atoms. United States. doi:10.1103/PHYSREVA.75.033412.
Buth, Christian, and Santra, Robin. Thu .
"Theory of xray absorption by laserdressed atoms". United States.
doi:10.1103/PHYSREVA.75.033412.
@article{osti_20982360,
title = {Theory of xray absorption by laserdressed atoms},
author = {Buth, Christian and Santra, Robin},
abstractNote = {An ab initio theory is devised for the xray photoabsorption cross section of atoms in the field of a moderately intense optical laser (800 nm, 10{sup 13} W/cm{sup 2}). The laser dresses the coreexcited atomic states, which introduces a dependence of the cross section on the angle between the polarization vectors of the two linearly polarized radiation sources. We use the HartreeFockSlater approximation to describe the atomic manyparticle problem in conjunction with a nonrelativistic quantumelectrodynamic approach to treat the photonelectron interaction. The continuum wave functions of ejected electrons are treated with a complex absorbing potential that is derived from smooth exterior complex scaling. The solution to the twocolor (xray plus laser) problem is discussed in terms of a direct diagonalization of the complex symmetric matrix representation of the Hamiltonian. Alternative treatments with timeindependent and timedependent nonHermitian perturbation theories are presented that exploit the weak interaction strength between x rays and atoms. We apply the theory to study the photoabsorption cross section of krypton atoms near the K edge. A pronounced modification of the cross section is found in the presence of the optical laser.},
doi = {10.1103/PHYSREVA.75.033412},
journal = {Physical Review. A},
number = 3,
volume = 75,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}

An ab initio theory is devised for the xray photoabsorption cross section of atoms in the field of a moderately intense optical laser (800 nm, 10{sup 13} W/cm{sup 2}). The laser dresses the coreexcited atomic states, which introduces a dependence of the cross section on the angle between the polarization vectors of the two linearly polarized radiation sources. We use the HartreeFockSlater approximation to describe the atomic manyparticle problem in conjunction with a nonrelativistic quantumelectrodynamic approach to treat the photonelectron interaction. The continuum wave functions of ejected electrons are treated with a complex absorbing potential that is derived from smoothmore »

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