Higher order and penumbral blurring correction methodology for Opacity spectrometer used on the NIF *

The Opacity Spectrometer (OpSpec) used on the NIF’s opacity experiments have gone through several iterations to help improve the signal to noise ratio by lowering background, alternate crystal planes reflections, and improvements in the spectral resolution, which help to increase the validity of the opacity measurements. However, higher order reflections are intrinsic to the crystal and the photon energy of the source. The opacity spectrometer measures x-ray spectra from the different experimental regions: the backlight source, emission source, and the absorption region. The transmission calculated from these regions is a convolution of the penumbra and higher order reflections effects. This work represents our result in deconvolving the 2^nd and 3^rd order spectral energy corrections with a penumbral de-blurring to correct the relative measurement of x-ray intensity of different spectral energies.