Time evolution of ion and electron temperatures in shock-driven implosions at OMEGA

Time evolutions of ion and electron temperatures in shock-driven implosions are separately assessed using simultaneously measured nuclear-reaction and X-ray-emission histories. In these DT³He-gas-filled implosions, the Particle X-ray Temporal Diagnostic (PXTD) on OMEGA is fielded to measure the DT and D³He reaction histories, as well as several X-ray-emission histories in different energy bands. A spatially-averaged T_i(t) is inferred from the reaction histories using the different temperature sensitivities of the DT and D³He reactions. A spatially-averaged T_e(t) is inferred from the ratios of the X-ray histories at different energy bands. These measured T_i(t) and T_e(t) have been used to explore ion-electron equilibration rates in different plasma conditions. Finally, the implementation and use of PXTD, which represents a significant advance at OMEGA, has laid the foundation for the implementation of a T_e(t) diagnostic in support of the main cryogenic DT programs on OMEGA. This work is supported in part by the U.S. DOE, LLNL, LLE, and NNSA SSGF.