Quick Shot

In collaboration with scientists at the National Ignition Facility (NIF), LLE scientists tested the instrument response function of a DPAC scintillator developed at Lawrence Livermore National Laboratory to detect fusion neutrons. Shown above is a photograph of a prototype neutron time-of-flight (nTOF) diagnostic designed and fabricated at LLE for the NIF and used for the testing on OMEGA. The radial geometry of the nTOF has the scintillator at the center to intercept the collimated neutron beam and the photomultiplier tubes positioned outside of the neutron beam to optimize the detector performance. It was used earlier on OMEGA to perform similar measurements on a bibenzyl scintillator [V. Yu. Glebov et al., Rev. Sci. Instrum. 83, 10D309 (2012)]. On a recent campaign the DPAC scintillator was tested using DT-fusion neutrons generated in an exploding pusher on the 60-beam OMEGA laser. The temporal response of the scintillator (i.e., fast decay and afterglow) was characterized. Additionally, the instrument response function was measured using short-pulse x rays produced during joint OMEGA and OMEGA EP shot operations. This collaboration demonstrates the strength of Omega Laser Facility for diagnostic development within the National Diagnostics Working Group.