Demonstration of a long pulse X-ray source at the National Ignition Facility

A long duration high fluence x-ray source has been developed at the National Ignition Facility (NIF). The target was a 14.4 mm tall, 4.1 mm diameter, epoxy walled, gas filled pipe. Approximately 1.34 MJ from the NIF laser was used to heat the mixture of (55:45) Kr:Xe at 1.2 atm (∼5.59 mg/cm3) to emit in a fairly isotropic radiant intensity of 400–600 GW/sr from the Ephoton = 3–7 keV spectral range for a duration of ≈ 14 ns. The HYDRA simulated radiant intensities were in reasonable agreement with experiments but deviated at late times.