Stimulated electronic x-ray Raman scattering.
We demonstrate strong stimulated inelastic x-ray scattering by resonantly exciting a dense gas target of neon with femtosecond, high-intensity x-ray pulses from an x-ray free-electron laser (XFEL). A small number of lower energy XFEL seed photons drive an avalanche of stimulated resonant inelastic x-ray scattering processes that amplify the Raman scattering signal by several orders of magnitude until it reaches saturation. Despite the large overall spectral width, the internal spiky structure of the XFEL spectrum determines the energy resolution of the scattering process in a statistical sense. This is demonstrated by observing a stochastic line shift of the inelastically scattered x-ray radiation. In conjunction with statistical methods, XFELs can be used for stimulated resonant inelastic x-ray scattering, with spectral resolution smaller than the natural width of the core-excited, intermediate state.
Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany and Center for Free-Electron Laser Science, 22761 Hamburg, Germany.
Clemens
C
Weninger
Colorado Sate University, Fort Collins, Colorado 80523, USA.
Michael
M
Purvis
Colorado Sate University, Fort Collins, Colorado 80523, USA.
Duncan
D
Ryan
Lawrence Livermore National Laboratory, Livermore, California 94551, USA.
Richard A
RA
London
LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
John D
JD
Bozek
LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
Christoph
C
Bostedt
Lawrence Livermore National Laboratory, Livermore, California 94551, USA.
Alexander
A
Graf
Lawrence Livermore National Laboratory, Livermore, California 94551, USA.
Gregory
G
Brown
Colorado Sate University, Fort Collins, Colorado 80523, USA.
Jorge J
JJ
Rocca
Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany and Center for Free-Electron Laser Science, 22761 Hamburg, Germany.
Nina
N
Rohringer