First Hohlraum Experiments at the National Ignition Facility

Summary form only given. Recently the first hohlraum experiments have been performed at the National Ignition Facility (NIF) in support of indirect drive inertial confinement fusion (ICF) and high energy density (HED) physics. Vacuum hohlraums have been irradiated with laser powers up to 8 TW, 1-9 ns pulse lengths and energies up to 17 kJ to activate several drive diagnostics, to study the hohlraum radiation temperature scaling with the laser power and hohlraum size, and to make contact with hohlraum experiments performed at the NOVA and Omega laser facilities. The vacuum hohlraums yielded low laser backscattering and hot electron fraction, and the hohlraum radiation temperature measured with a newly activated 18 channel Dante soft X-ray power diagnostic agreed well with two-dimensional LASNEX calculations. These hohlraum experiments have also validated analytical models and LASNEX calculations of hohlraum plasma filling as evidenced by time-resolved hard X-ray imaging and coronal hohlraum radiation production measured by Dante