TY - JOUR
T1 - Above-threshold ionization in the x-ray regime
AU - Varma, Hari R.
AU - Ciappina, Marcelo F.
AU - Rohringer, Nina
AU - Santra, Robin
PY - 2009/11/30
Y1 - 2009/11/30
N2 - Two-photon above-threshold ionization processes in the x-ray regime are studied using atomic hydrogen as a model system. Within the minimal-coupling formalism of nonrelativistic quantum electrodynamics, two distinct interactions-  □ p̂ in second order and  2 in first order-contribute to the two-photon absorption amplitude. The relative importance of these two interactions is assessed. It is found that above a photon energy of 6.8 keV, the contribution from  2 to the total two-photon absorption cross section dominates. In this high-energy regime, above-threshold ionization is a nonsequential purely nondipole process. Rate equations are employed to calculate the probabilities of ionization by Compton scattering, one-photon absorption, and two-photon absorption.
AB - Two-photon above-threshold ionization processes in the x-ray regime are studied using atomic hydrogen as a model system. Within the minimal-coupling formalism of nonrelativistic quantum electrodynamics, two distinct interactions-  □ p̂ in second order and  2 in first order-contribute to the two-photon absorption amplitude. The relative importance of these two interactions is assessed. It is found that above a photon energy of 6.8 keV, the contribution from  2 to the total two-photon absorption cross section dominates. In this high-energy regime, above-threshold ionization is a nonsequential purely nondipole process. Rate equations are employed to calculate the probabilities of ionization by Compton scattering, one-photon absorption, and two-photon absorption.
UR - http://www.scopus.com/inward/record.url?scp=70949094490&partnerID=8YFLogxK
U2 - 10.1103/PhysRevA.80.053424
DO - 10.1103/PhysRevA.80.053424
M3 - 文章
AN - SCOPUS:70949094490
SN - 1050-2947
VL - 80
JO - Physical Review A - Atomic, Molecular, and Optical Physics
JF - Physical Review A - Atomic, Molecular, and Optical Physics
IS - 5
M1 - 053424
ER -