Fast neutron irradiation damage on room temperature PbS detectors

The effects of high-energy neutron irradiation on the photoconductive properties of chemically-deposited PbS infrared detectors have been investigated in the I0
¹¹
n/cm
²
to 10
¹⁴
n/cm
²
fluence range. Long term degradation in signal response has been observed subsequent to room temperature irradiation of 2×10
¹²
n/cm
²
or greater fluetices. Seventy-five percent of the degradation can be attributed to a reduction in majority carrier lifetime, and the most likely source for the additional 25% reduction in the photoconductivity is the quantum efficiency. However, the degradation is not permanent. The recovery proceeds logarithmically with time. The dark resistance was unaffected by the irradiation. Additionally, if the detector views a visible light source simultaneously with the neutron irradiation, a significant increase in signal degradation rate is found.