Laser Plasma Interactions in High Energy Density Plasmas

摘要

High temperature hohlraums (HTH) are designed to reach high radiation temperatures by coupling a maximum amount of laser energy into a small target in a short time. These 400-800 (micro)m diameter gold cylinders rapidly fill with hot plasma during irradiation with multiple beams in 1ns laser pulses. The high-Z plasmas are dense, (electron density, n(sub e)/n(sub c) approximately 0.1-0.4), hot (electron temperature, T(sub e) approximately 10keV) and are bathed in a high-temperature radiation field (radiation temperature, T(sub rad) approximately 300eV). Here n(sub c), the critical density, equals 9x10(sup 21)/cm(sup 3). The laser beams heating this plasma are intense (approximately 10(sup 15) - 10(sup 17) W/cm(sup 2)). The coupling of the laser to the plasma is a rich regime for Laser-Plasma Interaction (LPI) physics. The LPI mechanisms in this study include beam deflection and forward scattering. In order to understand the LPI mechanisms, the plasma parameters must be known. An L-band spectrometer is used to measure the electron temperature. A ride-along experiment is to develop the x-radiation emitted by the thin back wall of the half-hohlraum into a thermal radiation source.