Response function and sensitivity of double-diffused silicon detectors in high γ-dose rate fields

Response Function and Sensitivity of Double-Diffused Silicon Detectors in High γ-Dose Rate Fields, R. W. Kuckuck, R. Bernescut, M. R. Zatzick and C. P. Jupiter - A number of double-diffused (PIN) silicon detectors were exposed to peak γ-dose rates of 1019 γ-MeV/cm²-sec generated by a flash x-ray machine. Detailed examination of the rate and linearity was accomplished by superposition of a 200 Mc Rossi signal on the oscilloscope traces of the test detector, as well as that of the non-saturable monitor detector. At detector bias voltages of 3000 V, and load impedances of 25 ohms, peak linear currents of approximately 48 amps were observed with rise times of less than 10 nanoseconds. Sensitivity measurements of the detectors were obtained at lower dose rates of about 1016 γ-MeV/cm²-sec by exposure to a thick target bremsstrahlung source, using a 10 MeV Linac beam. The current-time integral of a detector signal provided a measure of the charge per pulse and a thimble ionization chamber was used to measure the average dose per pulse. Sensitivities are provided in units of amp/cm²/γ-MeV/cm²-sec per micron of depletion depth. Results also include sensitivity vs detector bias voltage curves and calculated time response curves for an assumed δ-function gamma excitation pulse.