Measurements of Laser Coupling and Plasma Profiles in Longer-Scalelength Plasmas.

摘要

Novel configuration of our two-beam laser allows laser-coupling experiments to be performed in longer-scalelength plasmas (Ln approx. equal to nc/10), which better simulate reactor-sized pellet plasmas. Preliminary observations show increased backscatter, as expected, but also reveal large reduction in 2 omega 0 and high-energy x-ray emissions. The latter may indicate lessened importance of resonance absorption in longer-scalelength plasmas. Measurements of plasma profiles are at least as important as coupling measurements in these experiments and we show new diagnostic techniques based upon tracer-dot methods. These include the first techniques available for velocity profile measurement, was well as an improved x-ray spectroscopic method for density and temperature profile measurement. (Author)