Characterization of NIF spectrometers at the new LLNL calibration station

A variety of research projects performed at the National Ignition Facility (NIF) utilize X-ray spectrometers.  Characterizing and calibrating such instruments is of paramount importance in order to extract meaningful results from experiments.

A new calibration station has recently been implemented at LLNL, dedicated to the characterization of X-ray spectrometers. A wide energy range of X-ray emission ranging from a few keV to 30 keV with an adjustable source size between 0.2 mm and ~ 2 mm diameter is available. The x-ray source is connected to a vacuum experimental chamber capable of hosting an entire NIF spectrometer snout. Such configuration allows for throughput measurements providing absolute calibration of spectrometers. This talk will go over the throughput measurement process and present crystal characterization as well as integrated reflectivity measurements for two different NIF spectrometers, the Imaging Spectroscopy Snout (ISS) and the NIF X-ray Spectrometer (NXS). Each spectrometer can be equipped with different crystal configurations, 10 for the ISS and 12 for the NXS. The results for selected crystal configuration will be presented.