A METHOD FOR DETERMINING SCINTILLATOR RESPONSE FUNCTIONS FOR FAST NEUTRONS

摘要

An efficient method for determining the pulse-height response function of organic scintillators for fast neutrons has been developed. A pulsed beam of 14 MeV neutrons from the D-T reaction was generated by the Livermore ICT accelerator;the beam of neutrons was subsequently degraded by scattering in a one mean-free-path block of CH„ to pro¬duce a time-correlated polyenergetic burst of neutrons. The neutrons were detected at a flight path of 7.5 m with a full width at half maximum (FWHM) time resolution of 3 nsec. The timing error due to the scattering process was negli¬gible compared to the total flight time. Both time-of-flight and pulse-height in¬formation were accumulated for each detected event in a two-parameter ana¬lyzer. Using this method, the response functions were measured for Stilbene, Pilot B, NE-213, and NE-218 for neutrons with energies between 1 and 14 MeV. From these functions the loci of equivalent electron pulse heights were determined for each scintillator.