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 0.24–5.8keV and spectral resolution E∕ΔE>400, resulting in two to three times more spectral data than achieved by previous spectrometer designs. The observed 100ps temporal resolution and 35μm spatial resolution are consistent with the requirements of high energy density opacity experiments.