Characteristic X-rays generation under the action of femtosecond laser pulses on nano-structured targets

Enhancement of Kα yield from a metal foil covered with metal rods of submicron sizes, with low aspect ratio, irradiated by a p-polarized femtosecond laser pulses of about 1017 W/cm2 intensity is demonstrated. Obtained relative increase in Kα X-ray line emission is explained with a model of vacuum heating of fast electrons.