Piezoresistive micromechanical transducer operation in a pulsed neutron and gamma ray environment

We completed the third in a series of experiments using commercially available, piezoresistive microelectromechanical system (MEMS) transducers to instrument articles exposed to the intense, pulsed neutron and gamma ray radiation environment of Sandia National Laboratories´ Annular Core Research Reactor. Based on analyzing the survival of pressure transducers and accelerometers in the first two experiments, we identified candidate piezoresistive, MEMS transducers and then tested them by exposure to pulses, each with 10¹⁵ neutrons/cm² and 10⁴ Gy (1 Mrad) of gamma radiation. Simultaneous measurement of temperature indicates that the pressure transducers retain their calibrations and may provide a means of quickly identifying temperature-induced offset shifts of accelerometer calibrations. Comparison to other sensors that do not survive in this environment and implications for using these transducers to instrument test articles are also presented.