Diagnosing the hot-spot electron temperature from x-ray continnum emission measurements on NIF and OMEGA implosions*

The hot-spot electron temperature (Te) is a key metric in determining the performance of inertial confinement fusion (ICF) implosions. The Continuum Spectrometer (ConSpec) infers hot-spot Te from the slope of the x-ray continuum emission in the photon energy range of 20 to 30 keV, where ion velocity and opacity effects are negligible. Additionally, the ConSpec provides spatial resolution to resolve background x-ray sources from the hot-spot emission. We present initial x-ray spectra, from which we infer hot-spot Te for DT cryogenic implosions at both the National Ignition Facility (NIF) and the OMEGA laser facility. In the NIF experiments, we infer the hot-spot Te from the continuum emission and measure the emission spectra from the laser deposition region near the hohlraum wall (the gold bubble). For the OMEGA direct-drive implosions, we evaluate the effectiveness of spatially resolving the hot-spot emission in the time-integrated measurement from coronal plasma emission.