Principles of fast neutron detector package design for differential dieaway technique assay systems

Year
2002
Author(s)
S. Croft - Canberra Industries
S. Croft - Canberra Industries
Sheila Melton - Los Alamos National Laboratory
Sheila Melton - Los Alamos National Laboratory
L.C-A. Bourva - Canberra Industries
L.C-A. Bourva - Canberra Industries
M.J. Chard - UKAEA,
M.J. Chard - UKAEA,
Abstract
The Fast Neutron Detector Packages (FNDP’s) used in differential dieaway (DDA) technique assay systems should ideally have a high neutron detection efficiency and a short neutron residence time. In this paper we concentrate on the physics design process of Cd wrapped, polyethylene moderated, 3He filled proportional counter FNDP arrays needed to obtain a well balanced combined Passive neutron coincidence counting/DDA assay system. A combination of diffusion neutron transport theory and Monte Carlo modeling is used to illustrate how the main design parameters affect performance.