What can a 60 keV neutron beam do ?
Wolfgang Stoeffl
Tuesday, August 26, 2003
11:00 AM
Building 151, Room 1209 (Stevenson Conference Room)

Abstract:
We are developing a new method to search for SNM. The diffusion depth of 60 keV neutrons in average material is not much different from high energy neutrons, but the absence of high energy neutrons in the outgoing beam allows one to be very sensitive to the few returned high energy neutrons emitted from fissile material. It is a unique signature, even during the time when the outgoing neutron beam is still on. We not only develop the 60 keV neutron production system based on a very small RFQ linear proton accelerator, but also a novel energetic neutron detection system with a very high rejection ratio between energetic neutrons and gamma rays + thermal neutrons. Since practically all outgoing neutrons produce a cascade of high energy gamma rays when they capture somewhere in the vicinity of the instrument, the high rejection ratio is essential.
We will also use the energy and temporal signal from neutron and gamma spectra and their multiplicity.