The effect of a UV preionization pulse on short-wave radiation output from a laser-produced-plasma source with a Xe gas-jet target

Experiments aimed to raise the emissivity of a laser-produced plasma source with a Xe gas target in the far-UV spectral range are described. In these experiments, the main pulse of the IR Nd:YAG laser was preceded by a pre-ionization pulse of a UV KrF excimer laser. The consequences of applying the prepulse and its influence on the short-wavelength emission intensity were traced up to main-pulse delays of about 5 μs with respect to the prepulse. It is supposed that the main mechanism by which the prepulse affects the evolution of the plasma and its emission intensity is related to the density waves excited in the gas target by this pulse.