Measurement of time resolved electron temperature in cryogenic DT implosions at Omega with a multi-channel x-ray temporal diagnostic
ORAL
Abstract
In recent cryogenic ICF implosions at Omega, multiple x-ray histories were measured with a 4-channel x-ray temporal diagnostic using scintillators coupled to an optical streak camera. The relative signal amplitudes of the different channels are modeled by an time-dependent exponential bremsstrahlung emission spectrum, from which time-resolved electron temperature, Te(t), is inferred. This provides valuable diagnostic information, as Te is unaffected by residual flows and other non-thermal effects. Measurement of Te(t) will be used to investigate effects related to time-resolved hot spot energy balance including high-mode and low-mode asymmetries, residual ion-kinetic energy, radiative losses, and ion-electron equilibration in Omega cryogenic implosions. The current prototype diagnostic uses the existing neutron temporal diagnostic infrastructure which allows measurement of Te(t) with 40 ps time resolution and 15{\%} uncertainty at peak emission. A proposed dedicated diagnostic would achieve 5{\%} uncertainty with 20 ps time resolution.
*This work was supported in part by the U.S. DOE, the MIT/NNSA CoE, NLUF, and LLE.
–