Spectrum-Resolved Absolute Energy Measurement of X-Ray Emission in 0.17–1.6 keV Range from a 0.53 µm Laser-Irradiated Au Target

Spectrum-resolved absolute X-ray radiant energy emitted from 0.53 µm laser-irradiated planar Au plasmas was measured in the 0.17–1.6 keV range. The obtained spectral shape was found to considerably deviate from a blackbody spectrum. The conversion efficiency from the incident laser energy to radiant energy was investigated at the laser intensity range of 2×1013∼2×1015 W/cm2 with a nominal laser incident angle of 54° and determined to be 43% ± 13% for 1.0 nsec pulse and 20% ± 3% for 0.25 nsec at IL∼1014 W/cm2. The radiant energy above 1.6 keV was less than 1% of the incident laser energy.