FRESNEL ABSORPTION, RESONANCE-ABSORPTION, AND X-RAYS IN LASER-PRODUCED PLASMAS

Assuming Fresnel absorption for s-polarized light and resonance absorp tion for p-polarized light provides agreement with the significant fea tures of subpicosecond high-intensity KrF laser-produced plasma experi ments. These features include the s- and p-light angular dependence an d magnitude of the reflectance. Dramatic differences exist in the thre shold for emission of x-ray photons above 0.5 keV, the x-ray emission intensity, and the efficiency for x-ray production by absorbed p and s light. It is shown that resonant p-light absorption occurs at the las er critical density and that the s-light absorption at a higher electr on density causes more efficient x-ray production by p light than by s light.