Charge multiplication in epitaxial silicon fission-fragment detectors

Experimental data on charge multiplication in the response of silicon epitaxial detectors to Cf-252-spontaneous-fission fragments are presented, Fission-fragment energy distributions measured for various bias voltages applied to the detector (from 6 to 42 V) are obtained. Transformation of normal-and multiplied-pulse distributions with a rise in the bias voltage is analyzed. The obtained data show the usefulness of a model based on the mechanism of collision ionization in a strong electric field resulting from the accumulation of mobile charge carriers close to the input detector electrode.