RADIATION-INDUCED CONDUCTIVITY IN ALPHA-AL2O3 CRYSTALS

Radiation induced conductivity in alpha Al2O3 crystals is studied duri ng excitation by subnanosecond pulses from an electron accelerator, At least three components are observed in the relaxation of the conducti on current, A component of the conduction current which follows the ex citing pulse without delay is not observed, as, for example, in NaCl a nd KCl crystals. This is followed by a subnanosecond decay that does n ot fit a simple pattern and then, to within the limits of the sensitiv ity of the apparatus, by al least two other relaxation components for the conduction current in the nanosecond range. It is assumed that the observed components of the conduction current relaxation, including t he fastest, are caused by thermal release of carriers from traps and t heir subsequent redistribution, while the second and third components of the conduction current pulse appear to the associated with electron s, (C) 1997 American Institute of Physics.