A high-resolving-power x-ray spectrometer for the OMEGA EP Laser (invited)

Abstract

A high-resolving-power x-ray spectrometer has been developed for the OMEGA EP Laser System based on a spherically bent Si [220] crystal with a radius of curvature of 330 mm and a Spectral Instruments (SI) 800 Series charge-coupled device. The instrument measures time-integrated x-ray emission spectra in the 7.97- to 8.11-keV range, centered on the Cu K line. To demonstrate the performance of the spectrometer under high-power conditions, K emission spectra were measured from Cu foils irradiated by the OMEGA EP laser with 100-J, 1-ps pulses at focused intensities above 10 W/cm. The ultimate goal is to couple the spectrometer to a picosecond x-ray streak camera and measure temperature-equilibration dynamics inside rapidly heated materials. The plan for these ultrafast streaked x-ray spectroscopy studies is discussed.

Experimental characterization of hot-electron emission and shock dynamics in the context of the shock ignition approach to inertial confinement fusion

“…This spectrometer uses a curved HOPG crystal in von Hamos geometry to diagnose the x-ray spectrum in the range of 7 − 10 keV. A high-spectral resolution x-ray spectrometer (HRS) used a spherically bent Si [220] crystal coupled to a charge-coupled device to measure the time-integrated x-ray emission in the 7.97-to 8.11-keV range [11]. The hot-electron-produced bremsstrahlung radiation was diagnosed by two timeintegrating hard x-ray spectrometers (BMXSs) [12] at 25 • and 65 • off the target rear normal, respectively.…”

Inertial confinement fusion for energy: overview of the ongoing experimental, theoretical and numerical studies

“…Thanks to its peak power exceeding the petawatt (PW), the NIF advanced radiographic capability (ARC) will soon provide unique x-ray and proton radiography capabilities to diagnose the fuel compression phase with a temporal resolution of the order of picosecond, thus contributing to elucidate the remaining issues and to progress towards ignition. Implementation of highresolution x-ray spectroscopy will also allow new insights into the mix in close-to-stagnation capsules [16], a diagnostic technique that has already proven its efficiency on OMEGA [17,18].…”

Double-spherically bent crystal high-resolution X-ray spectroscopy of spatially extended sources

“…X-ray spectra of laser-produced plasmas (LPPs) have been intensively investigated [1][2][3][4][5] . The X-ray emission spectra from LPPs have been routinely measured using crystal spectrometers with both energy and spatial resolutions [6][7][8][9] . Measurements of temperature and density of high-temperature plasma with crystal analyzers have been increasingly embraced by researchers who seek to study radiation-sensitive resonance lines along with the adjacent weaker lines, i.e., the intercombination line, and a blend of multi-electronic satellites.…”