Impact of gamma radiation on range finding sensor performance

The effect of gamma radiation on common sensors in robots intended for nuclear remediation scenarios is examined. Rangefinders are chosen as an exemplar of the impact of gamma radiation on sensors and systems. This work extends previous work by calculating not just sensor failure point but changes in the sensor transfer function of three different types of commercial range-finding sensors (infrared (IR) triangulation using a position sensitive detector, sonar using time of flight, and laser range finder using triangulation and a CMOS camera) in response to gamma total radiation dose. Experimental results show significant changes in the IR sensor's static sensitivity with dose, abrupt failure of the laser range finder at low dose, and degradation and abrupt failure for the sonar detector. The input-output relationship of the IR sensor showed further variation after a period of room-temperature annealing. Significant part-to-part variation in radiation response is shown for both the sonar and IR sensor.