ANALYSIS OF SCINTILLATOR PULSE SHAPES FOR NEUTRON – GAMMA RAY DISCRIMINATION

Year
2004
Author(s)
John T. Mihalczo - Oak Ridge National Laboratory
Jarrod D. Edwards - Oak Ridge National Laboratory
Sara Pozzi - Oak Ridge National Laboratory
John S. Neal - Oak Ridge National Laboratory
P.J. McClanahan - Oak Ridge National Laboratory
Abstract
Neutron and gamma ray pulse shape discrimination with liquid scintillators is a widely adopted technique with applications in many fields. When liquid scintillators are used as neutron detectors, pulse shape discrimination is used to eliminate gamma ray pulses. Typically the decision times in commercially available modules are in the microsecond time range. However, some applications require a much shorter decision time to improve the measurement efficiency. This paper presents the results of the analysis of a large number of neutron and gamma ray pulses collected with a liquid scintillation detector using a Tektronix digital oscilloscope. The objective of this research was to investigate new methods for neutron – gamma ray pulse shape discrimination. The paper presents an analysis of pulse shape and possible pulse shape discrimination algorithms. These include charge integration, zero crossing, and alternative methods. The algorithms consider times in the 0 to 120 ns time range from the pulse peak.