Measurements of shock-bang and compression-bang time in NIF implosions using the particle Time-of-Flight (pTOF) diagnostic

The nuclear shock-bang and compression-bang times provide unique information about the shock physics in, and dynamics of, ICF implosions at the National Ignition Facility (NIF). The shock-bang time may address questions about fuel preheat, whereas compression-bang time is an indicator of energy coupling to the capsule. The particle Time-of-Flight diagnostic (pTOF), recently implemented on the NIF, measures the bang times using shock-generated D$^{3}$He protons and compression-generated DD-neutrons in D$^{3}$He gas-filled tuning shots at the NIF. In combination with a Wedge Range-Filter (WRF) proton spectrometer fielded at the pTOF, time-resolved $\rho $R measurements are also conducted. The diagnostic also measures the bang time in cryogenic DT and DT-Exploding Pusher implosion. The pTOF results from the tuning campaigns in 2011 will be presented, and the implications of the data will be discussed. This work was supported in part by the U.S. DOE, LLNL and LLE.