X-ray Generation by High Irradiance Subpicosecond Lasers

The pumping of short wavelength x-ray lasers requires very large power. The most widely used method for recombination schemes utilizes direct heating of the lasant with laser irradiation followed by relaxation to the desired levels. We prefer to use selected x-ray lines to pump the x-ray laser in a manner similar to dye lasers. This selective method reduces the x-ray pump energy requirements as well as the extraneous heating that accompanies the pumping, but requires high irradiance. We have been studying the generation of intense x-ray pulses using the interaction of a subpicosecond uv laser pulses with appropriate solid targets.