Title: Design and Optimization of Li-6 Neutron-Capture, Pulse Mode Ion
Chamber

Abstract:

The purpose of this ongoing research is to design and optimize the
performance of a unique, inexpensive 6Li neutron-capture, pulse mode
ion chamber (LiPMIC) for neutron detection that can overcome the
fill-gas contamination stemming from outgas of detector parts. This
research will also provide a demonstration of performance of
LiPMICs. Simulations performed with Garfield, a drift-chamber
simulation package for ion transport in an electrostatic field, have
shown that certain mixtures of fill-gas allow maintaining similar
electron drift velocity through a surprisingly wide range of fill-gas
content. This novel pulse-mode ion chamber is specifically designed as
one of several cost-effective instruments that have the potential to
fulfill the needs for large-scale deployment in a distributed network
of remote sensors. The detector is expected to provide non-invasive
interrogation of goods and personnel at borders, ports, strategic
landmarks, and buildings for detecting nuclear materials such as
plutonium. The LiPMIC is expected to provide neutron detection
capability for deployment for homeland security and nuclear material
control and accountability applications at the comparable performance
level to the currently available neutron detectors, such as 3He
proportional counters, while reducing the initial procurement cost by
an order of magnitude.