Device Test

Device Test

Inverse gain degradations of 2N222A BJT device have been characterized and Sulfur and Iron foils have been used as dosimetry monitor foils. Measured neutron intensities are compared to MCNPX calculations and legacy systems. The legacy systems are the Sandia Pulsed Reactor (SPR-III), White Sands Missile Range's Fast Burst Reactor (WSMR FBR), the Annular Core Research Reactor (ACRR), and the Los Alamos Neutron Science Center (LANSCe). The NREF gain degradations slightly fall below the expected values because of Annealing due to the pulsed based neutron source. The legacy systems have traditional, single pulse, high intensity neutron sources.

NREF data on change in gain of a 2N222A transistor with neutron flux to published data. NREF data agree with the legacy data to within 20% over the range of 0.5 to 2.5x1014 n/cm2