Broadband high-resolution elliptical crystal x-ray spectrometer for high energy density physics experiments

The spectroscopic investigation of high temperature laser produced plasmas in general, and x-ray opacity experiments in particular, often requires instruments with both a broad coverage of x-ray energies and high spectral, spatial, and temporal resolution. We analyze the design, model the response, and report the commissioning of a spectrometer using elliptical crystals in conjunction with a large format, gated microchannel plate detector. Measurements taken with this instrument at the Janus laser facilities demonstrate the designed spectral range of 0.24-5.8 keV and spectral resolution E/Delta E > 400, resulting in two to three times more spectral data than achieved by previous spectrometer designs. The observed 100 ps temporal resolution and 35 mu m spatial resolution are consistent with the requirements of high energy density opacity experiments.