Nonsequential two-photon absorption from the K shell in solid zirconium

Authors

Shambhu Ghimire, SLAC National Accelerator Laboratory
Matthias Fuchs, University of Nebraska - LincolnFollow
Jerry Hastings, SLAC National Accelerator Laboratory
Sven C. Hermann, SLAC National Accelerator Laboratory
Yuichi Inubushi, RIKEN SPring-8 Center
Jack Pines, SLAC National Accelerator Laboratory
Sharon Shwartz, Bar Ilan University
Makina Yabashi, SLAC National Accelerator Laboratory
David A. Reis, SLAC National Accelerator Laboratory

Date of this Version

2016

Document Type

Article

Citation

PHYSICAL REVIEW A 94, 043418 (2016)

Comments

©2016 American Physical Society

Abstract

We report the observation of nonsequential two-photon absorption from the K shell of solid Zr (atomic number Z = 40) using intense x-ray pulses from the Spring-8 Angstrom Compact Free-Electron Laser (SACLA). We determine the generalized nonlinear two-photon absorption cross section at the two-photon threshold in the range of 3.9–57 ×10⁻⁶⁰ cm⁴ s bounded by the estimated uncertainty in the absolute intensity. The lower limit is consistent with the prediction of 3.1 ×10⁻⁶⁰ cm⁴ s from the nonresonant Z⁻⁶ scaling for hydrogenic ions in the nonrelativistic, dipole limit.