SEMICONDUCTOR-DETECTORS FOR USE IN HIGH RADIATION-DAMAGE ENVIRONMENTS- SEMIINSULATING GAAS OR SILICON

There is a need for high-resolution solid-state tracking detectors for use in high radiation, long-life experiments where there can be consi derable degradation in their electrical performance. A discussion is g iven of the relative merits of GaAs and silicon in the context of the underlying semiconductor device physics. Although the relative perform ance, in terms of the charge collection efficiency at the end of life, depends on the details of the type and amount of damage produced, it is shown that the qualitative electrical behaviour is predictable usin g relaxation semiconductor theory. Experimentally, diodes of semi-insu lating GaAs and irradiated silicon have similar qualitative performanc e. Suggestions are given as to how the performance may be improved.