We report on the use of x-ray spectroscopy of mid- $Z$ dopants to measure the electron temperature of hohlraum targets. The hohlraums are gas-filled Au cylinders and, when irradiated with 20 kJ of $0.35\mu \mathrm{m}$ laser light, they become mm-sized plasmas bathed in a radiation field. The peak temperatures achieved by the target are 3.7 keV. In addition to being the first electron temperature measurements of the hohlraum itself, these measurements enable an investigation of the thermal energy and electron conduction of the target.

• Received 5 February 1996

DOI:https://doi.org/10.1103/PhysRevLett.77.4350