Simultaneous Measurement of Local Gain and Electron Density in
X-ray Lasers
R. Cauble,
*
L. B. Da Silva,
T. W. Barbee Jr.,
P. Celliers,
C. Decker,
R. A. London,
J. C. Moreno,
J. E. Trebes,
A. S. Wan,
F. Weber
X-ray lasers (XRLs) have experimental average gains that
are significantly less than calculated values and a persistently low
level of spatial coherence. An XRL has been used both as an injected
signal to a short XRL amplifier and as an interferometer beam to
measure two-dimensional local gain and density profiles of the XRL
plasma with a resolution near 1 micrometer. The measured local gain is
in agreement with atomic models but is unexpectedly spatially
inhomogeneous. This inhomogeneity is responsible for the low level of
spatial coherence observed and helps explain the disparity between
observed and simulated gains.
Lawrence Livermore National Laboratory, University of California,
Livermore, CA 94550, USA.
* To whom correspondence should be addressed.