Variations in the β -particle counting properties of diamond

Abstract

The electrical counting response of nine small type 2 diamonds to Ra E β -particles has been examined at room temperature and in the temperature range 288 to 610° K. At room temperature five of the diamonds could be very strongly activated by β -particle irradiation; in the activated state the counters did not polarize in the dark, even when operated for long periods at constant field. The counting efficiency in the activated state was estimated. Deactivation could be produced by irradiation with white light. The counting rate of activated diamonds varied considerably with temperature. For heating rates of about 1·5°K min -1 counting rate maxima were found in several specimens at temperatures of approximately 300 and 440°K. An attempt has been made to estimate the depths of traps believed to be responsible for these maxima; the values obtained are about 0⋅5 and 0⋅8 eV. It is suggested that the activation process may be attributed, in part, to trap saturation.