Generation of vacuum ultraviolet and extreme ultraviolet radiation by nonlinear processes with excimer lasers. Final report.

摘要

Atomic and molecular materials exhibit complex behavior when exposed to strong externally applied influences. A research program, concerning one aspect of this general problem, whose goal is the understanding of the nonlinear processes governing the coupling of intense radiation to atomic matter, is currently underway at the University of Illinois at Chicago. The general amplitude under study is N(gamma) + X (yields) X(sup q) + qe(sup (minus)) + (gamma)(prime) a class of processes which involves ionization with the collateral production of energetic electrons and radiation. Recently developed ultraviolet light sources are enabling the attainment of focal intensities on the order of (approximately) 10(sup 21) W/cm(sup 2), an extremely high value corresponding e/a(sub o)(sup 2). In a force field of this extraordinary strength, the induced electronic motions are strongly relativistic. This is a completely unexplored regime of interaction experimentally and one in which current theroetical descriptions provide little guidance. A program of experimental studies pertaining to processes occurring under these conditions is being conducted. It is likely that now phenomena will be observed under the unusual physical conditions that characterize the interactions explored in this research and that the findings will lead to a new means for the production of intense radiation in the x-ray range.