HTPD 2018

The Magnetic Recoil neutron Spectrometer (MRS) at the OMEGA laser facility has been routinely used to measure deuterium-tritium (DT) yield and areal density in cryogenically layered implosions since 2008. Recently, operation of the OMEGA MRS in higher-resolution mode with a smaller, thinner (4 cm2, 57-um thick) CD conversion foil has also enabled inference of the apparent DT ion temperature (Tion) from MRS data. Tion inferred from the broadening of the MRS-measured primary DT neutron spectrum compares well with neutron time-of-flight-measured Tion. This result is important as it demonstrates good understanding of the different systematics associated with the two independent measurements. The MRS resolution in this configuration (sigma=0.37 MeV) is still higher than required for a high-precision Tion measurement. In this contribution, we also discuss paths forward for further improving the resolution of the OMEGA MRS, including fielding a smaller foil closer to target chamber center. This work was supported in part by the U.S. Department of Energy and by the Laboratory of Laser Energetics under Contract 415935-G.