Nuclear radiation tolerance of single crystal Aluminum Nitride ultrasonic transducer

Abstract

For practical use in harsh radiation environments piezoelectric materials are proposed for Structural Health Monitoring (SHM), Non-Destructive Evaluation (NDE) and material characterization. Using selection criteria, piezoelectric Aluminum Nitride is shown to be an excellent candidate. The results of tests on an Aluminum Nitride based ultrasonic transducer operating in a nuclear reactor are presented. The tolerance is demonstrated for a single crystal piezoelectric aluminum nitride after a gamma dose and a fast and thermal neutron fluence, respectively. The radiation hardness of AlN is most evident from the unaltered piezoelectric coefficient after a fast and thermal neutron exposure in a nuclear reactor core for over several months in agreement with the published literature value. The results offer potential for improving reactor safety and furthering the understanding of radiation effects on materials by enabling structural health monitoring and NDE in spite of the high levels of radiation and high temperatures known to destroy typical commercial ultrasonic transducers.