A Low-Power, Real-Time Displacement Damage Dosimeter

The Naval Research Laboratory has developed a low-power, real-time displacement damage dosimeter (RT3D). RT3D consists of two components; one being the measurement electronics and the second being the actual dosimeter (GaAs diode) exposed to the radiation source. RT3D accumulates displacement damage passively (without power) and the displacement damage dose (DDD) is measured at will with measurement electronics by measuring the GaAs diode dark current at one or more forward bias voltages. The DDD is subsequently determined in real-time from a calibration curve derived from ground-based testing. The dosimeter is capable of measuring approximately three orders of magnitude in DDD. The dosage measurement range of the sensor can be modified by placing an absorber material over the sensor. Proton testing performed in situ yielded an error estimate determination to within 10% for simulated space use.