Improved neutron time of flight apparatus

Time-of-flight (ToF) facilities are useful for determining the energy spectra of neutrons from nuclear reactions. The ToF apparatus at Brigham Young University is used to support laboratory nuclear astrophysics research; products of both fission and fusion reactions are of particular interest. Reported here are improvements made to our apparatus. In the past, the gamma start pulse was detected with a 5'' x 5'' NaI(Tl) scintillator with a 10 dynode PMT. The current start detector uses a 5'' x 2'' EJ-200 plastic scintillator with a 14 dynode PMT. The plastic detector has improved timing resolution over the NaI(Tl) detector. Future plans include replacing our sealed Cf-252 source with a Cf fission chamber. We're anticipating using this facility to improve understanding of the fission process.