Laser-Compton scattering (LCS) experiments were carried out at the
Idaho Accelerator Center (ICA) using the 5 ns (FWHM) and 22 MeV electron
beam. The electron beam was brought to an approximate head-on collision
with a 7 ns (FWHM), 10 Hz, 29 MW peak power Nd:YAG laser. We observed
clear and narrow X-ray peaks resulting from the interaction of
relativistic electrons with the 532 nm Nd:YAG laser second harmonic line
on top of a very low bremsstrahlung background. We have developed a method
of using LCS as a non-intercepting electron beam monitor. Unlike the
method used by Leemans et al. (1996),
our method focused on the variation of the shape of the LCS spectrum
rather than the LCS intensity as a function of the observation angle in
order to extract the electron beam parameters at the interaction region.
The electron beam parameters were determined by making simultaneous fits
to spectra taken across the LCS X-ray cone. We also used the variation of
LCS X-ray peak energy and spectral width as a function of the detector
angles to determine the electron beam angular spread, and direction and
compared the results to the previous method. Experimental data show that
in addition to being viewed as potential bright, tunable and monochromatic
X-ray source, LCS can provide important information on electron beam pulse
length, direction, energy, angular, and energy spread. Since the quality
of LCS X-ray peaks, such as degree of monochromaticity, peak energy and
flux, depends strongly on the electron beam parameters, LCS can therefore
be viewed as an important non-destructive means for electron beam
diagnostics.
Characteristics of X-rays produced via laser Compton scattering using quasi-monoenergetic electron beam driven by laser-plasma acceleration