Amorphous silicon position sensitive neutron detector

Abstract

The authors considered the possibility of using an a-Si:H diode, coated with an appropriate converter, as a position-sensitive neutron detector. The Monte Carlo simulation predicted that by using a Gd film, approximately 2 mu m thick, coated on a sufficiently thick amorphous silicon n-i-p diode, a neutron detection efficiency of 25% could be achieved. The experimental results gave an average signal size of about 12000 e/sup -/ per neutron interaction, which was well above the noise and was in good agreement with the expected values. Pixel detectors can also be fabricated with an element size as small as 300 mu m and still register a count rate of 2200 events/s in a typical neutron flux situation of about 10/sup 7/ n/cm/sup 2/s. These detectors were not sensitive to gamma rays, and showed excellent radiation hardness.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>