Calibration of AGFA D4 and D3sc X-Ray Films in the 0.7 to 4.6 keV Energy Range for NIF Opacity Spectrometer.*

X-ray films still remain a key asset for high-resolution X-ray spectral imaging in High-Energy Density (HED) experiments conducted at the National Ignition Facility (NIF). The soft X-ray Opacity Spectrometer (OpSpec) fielded at the NIF has an elliptically shaped crystal design that measures X-rays in the 900-2100 eV range and currently uses image plates as the detecting medium. However, the higher spatial resolution of AGFA D4 and D3sc X-ray films provides increased spectral resolution to the data over the current IP-TR image plates, which drives the new iteration of OpSpec to include X-ray film as a detecting medium. The calibration of AGFA D4 and D3sc X-ray films used in new iterations of the OpSpec is communicated here. These calibration efforts are vital to the NIF opacity measurements and are conducted in a previously un-studied X-ray energy range under a new film development protocol required by NIF. The absolute response of AGFA D4 and D3sc X-ray films from 705 to 4620 eV is being measured using the Nevada National Security Site Manson X-ray source with select anodes and filters to produce well-defined X-ray line energies.