Neutron and Gamma-Ray Rate Sensitivities of Several Dynamic Detectors Used in Radiation Effects

The absolute rate-sensitivities of several burst sensors to neutrons and to gamma-rays in the mixed field of the Sandia pulsed reactor environment have been measured, using the shielding techniques of Coppage and Snyder(1) for variation of the neutron-to-gamma ray ratio over a factor of five to ten. The spectral changes effected by the shields are discussed. The sensors which were tested are: two reverse-biased preirradiated silicon diodes, MgO-RAD, phosphorphotodiode, and a fission (U238) detector. The ratio of the sensitivities of the detectors are 4. 8, 7.8, 9.1, 22, and 46 (x10-11 R-cm2/neutron (Pu)), respectively.