Direct Fast-Neutron Detection: A Progress Report

Technical Report · Sun Oct 18 04:00:00 EDT 1998

OSTI ID:6370455

Peurrung, AJ; Stromswold, DC; Reeder, PL; RR, Hansen

It is widely acknowledged that Mure neutron-detection technologies will need to offer increased performance at lower cost. One clear route toward these goals is rapid and direct detection of fast neutrons prior to moderation. This report describes progress to date in an effort to achieve such neutron detection via proton recoil within plastic scintillator. Since recording proton-recoil events is of little practical use without a means to discriminate effectively against gamma-ray interactions, the present effort is concentrated on demonstrating a method that distinguishes between pulse types. The proposed method exploits the substantial difference in the speed of fission neutrons and gamma-ray photons. Should this effort ultimately prove successful, the resulting. technology would make a valuable contribution toward meeting the neutron-detection needs of the next century. This report describes the detailed investigations that have been part of Pacific Northwest National Laborato s efforts to demonstrate direct fast-neutron detection in the laboratory. Our initial approach used a single, solid piece of scintillator along with the electronics needed for pulse-type differentiation. Work to date has led to the conclusion that faster scintillator and/or faster electronics will be necessary before satisfactory gamma-ray discrimination is achieved with this approach. Acquisition and testing of both faster scintillator and faster electronics are currently in progress. The advanced approach to direct fast-neutron detection uses a scintillating assembly with an overall density that is lower than that of ordinary plastic scintillator. The lower average density leads to longer interaction times for both neutrons and gamma rays, allowing easier discrimination. The modeling, optimization, and design of detection systems using this approach are described in detail.

• Research Organization: Pacific Northwest National Laboratory, Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6370455
• Report Number(s): PNNL-11994; Proj ID 27552; ON: DE00001230
• Country of Publication: United States
• Language: English

Related Subjects

440000* -- Instrumentation
47 OTHER INSTRUMENTATION
BARYONS
DETECTION
ELEMENTARY PARTICLES
FERMIONS
HADRONS
MEASURING INSTRUMENTS
NEUTRONS
NUCLEONS
RADIATION DETECTORS
SCINTILLATION COUNTERS