Efficient keV X-ray Generation from Irradiation of in-situ Produced Silver Clusters by Ti:sapphire Laser Pulses

An experimental study of energy absorption and x-ray emission from ultrashort laser pulse irradiation of in-situ produced solid clusters has been performed. Silver clusters produced by a 30 mJ, 300 ps laser pulse were irradiated up to an intensity of 3×1017 W/cm2 by a 70 mJ, 45 fs compressed laser pulse from the same Ti:sapphire laser. Absorption of the laser light exceeding 70 % was observed, resulting in an x-ray yield (>1 keV) of ~ 60 μJ / pulse. This may constitute a much simpler means of intense x-ray generation using ultrashort laser pulses as compared to the irradiation of structured / pre-deposited cluster targets, and it offers higher x-ray conversion efficiency than that from gas clusters and planar solid targets