Measurevent of the Transient Effects of a Gamtma-Flux on the Energy Resolution of Surface-Barrier Silicon Detectors

The energy resolutions of surface barrier n-type silicon detectors counting al pha-particles were measured under the disturbance of 1.25 MeV gamma-fluxes ranging from 2.3 x 107 to 3.8 x 108 photons cm-2 sec-1 and for detectors having different total thicknesses and resistivities. The results obtained confirm the existence of a zone about 100 micron wide and external to the depletion layer of partially depleted detectors which contributes to worsen the energy resolution of the gamma-irradiated detectors by diffusion rrocesses. It is also pointed out that the energy resolution of the detectors under gamma irradiation varies with the time constants of the amplifying circuit quite differently from what is obser ved in the absence of gamma irradiation.