New Neutron Radiation Effects Capabilities at the Low Energy Neutron Source (LENS)

The Low Energy Neutron Source (LENS) is a novel, university-based pulsed neutron source located within the Center for Explo- ration of Energy and Matter (CEEM) at Indiana University. The source utilizes a low energy p-n reaction in Beryllium coupled with a high-current, variable-pulse-width proton accelerator to produce either short or long neutron pulses. One of the target stations has been optimized for neutron radiation effects studies of device and board level electronics testing with quasi monochromatic high flux neutron beams (∼ 1 MeV equivalent silicon). The total neutron flux at the device under test (DUT) is approximately 2 · 1010 (n/cm2/sec) with low gamma contamination, 1 · 109 (n/cm2/sec). The neutron spectrum at the DUT position has been calculated using MCNP-X and has been characterized using foil activation measurements. In this paper we will describe the physical arrange-ment of the Device Test Area and indicate the unique features that have been incorporated to enhance testing effectiveness. We will also present the results of MCNP-X calculations with various adsorbed reflector arrangements that modify the spectrum incident on the device. Validation of the MCNP-X calculations using foil activation measurements will also be presented.