Evaluation of laser-irradiated Ar clusters as a source for time-resolved x-ray studies

In English We have measured the absolute average photon flux, the spectral characteristics, and the time structure of x rays emitted from Ar clusters which were irradiated by a 100 fs laser with an intensity of 10(17) W/cm(2). The measured photon flux was 10(7) photons per shot in the K-alpha (at 3 keV) line in a 4 pi sr solid angle. The temporal structure was measured using a streak camera with a 10 ps time resolution. It was found that less than 1% of the photons were emitted within the 10 ps time-response function of the streak camera. The emission profile is roughly exponential with a time constant of 3 ns. (C) 1999 American Institute of Physics. S0034-6748(99)03605-9.