Electric-octupole and pure-electric-quadrupole effects in soft-X-Ray photoemission
Second-order [ O(k(2)), k = omega/c] nondipole effects in soft-x-ray photoemission are demonstrated via an experimental and a theoretical study of angular distributions of neon valence photoelectrons in the 100-1200 eV photon-energy range. A newly derived theoretical expression for nondipolar angular distributions characterizes the second-order effects using four new parameters with primary contributions from pure-quadrupole and octupole-dipole interference terms. Independent-particle calculations of these parameters account for a significant portion of the existing discrepancy between experiment and theory for Ne 2p first-order nondipole parameters.
Derevianko
A
Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA.
Hemmers
O
Oblad
S
Glans
P
Wang
H
Whitfield
SB
Wehlitz
R
Sellin
IA
Johnson
WR
Lindle
DW