A sensitive neutron spectrometer for the National Ignition Facility

We are developing a sensitive neutron spectrometer for the National Ignitio n Facility laser at Livermore. The spectrometer will consist of a 1020 chan nel single-neutron-interaction time-of-flight detector array fielded 23 m f rom the neutron-producing target. It will use an existing detector array to gether with upgraded electronics for improved time resolution. Measurements of neutron yield, ion and electron temperatures, and density-radius produc t are all possible under certain conditions using one-, two-, or three-step reaction processes. The locations of the most important potential sources of scattered neutron backgrounds are determined as the first step in design ing collimation to reduce these backgrounds. (C) 2001 American Institute of Physics.