Silicon Junctions as Particle Spectrometers

Both Au-Si surface barriers and silicon p-n junctions operate satisfactorily as particle spectrometers. The use of high resistivity material gives a depletion region wide enough to stop high-energy protons, ?? particles, and heavier ions. A resolution of 16 kev (width at half-maximum) for 6.04 mev ?? particles is obtained with a junction depletion layer sufficient to stop 10 mev ?? particles. With the depletion region very close to the surface, ?? particles in the range from 10 kev to several hundred kev are detectable. The pulse amplitude distribution from Co57 indicates the presence of the two well-known lines at 115 and 129 kev. An attempt has been made to correlate the observed performance with the semiconductor parameters and the diode static characteristics.