Predicted four-wave mixing and tripling rates for neonlike yttrium x-ray laser radiation in sodiumlike plasmas

Presented are predicted conversion rates for four-wave mixing of the output of the Ne-like Y soft-x-ray laser (15.495 nm) with that of an optical laser in a Na-like Ca plasma to give radiation at ~ 7.8 nm (approximate frequency doubling). Also presented are frequency tripling rates of the Ne-like Y laser in a Na-like V plasma to give radiation at 5.165 nm. In each case the nonlinear susceptibilities and converted intensities are calculated, and phase-matching considerations are discussed.