Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1826117 | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | 2010 | 4 Pages |
Abstract
A new, accurate, neutron activation detection scheme for measuring pulsed neutrons has been designed and tested. The detection system is sensitive to neutrons with energies above 10Â MeV; importantly, it is insensitive to gamma radiation <10Â MeV and to lower-energy (e.g., fission and thermal) neutrons. It is based upon the use of 141Pr, an element that has a single, naturally occurring isotope, a significant n,2n cross-section, and decays by positron emission that result in two coincident 511Â keV photons. Neutron fluences are thus inferred by relating measured reaction product decay activity to fluence. Specific sample activity is measured using the sum-peak method to count gamma-ray coincidences from the annihilation of the positron decay products. The system was tested using 14 and 2.45Â MeV neutron bursts produced by NSTec Dense Plasma Focus Laboratory fusion sources. Lead, copper, beryllium, and silver activation detectors were compared. The detection method allows measurement of 14Â MeV neutron yield with a total error of â18%.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Instrumentation
Authors
Tim Meehan, E.C. Hagen, C.L. Ruiz, G.W. Cooper,