Synthesis and Characterization of Hexagonal Boron Nitride for Neutron Radiation Detection

Location: Bldg. 6/Room 125

In current space missions, radiation exposure during extravehicular activities is primarily assessed through post-mission analysis using dosimeter badges, highlighting the need for real-time detection to enhance astronaut safety. In this talk, I will discuss the development of a real-time radiation detection system using graphene field-effect transistors (gFETs) and monoisotopic hexagonal boron nitride (hBN). Monoisotopic hBN was synthesized via a metal flux method and characterized before and after neutron irradiation using various spectroscopic techniques. The study used two types of neutron sources, a deuterium-deuterium neutron generator, and an Americium-Beryllium isotopic source, to observe the effects of neutron irradiation on hBN. It was found that neutron irradiation could induce specific defects in hBN, particularly the VB- defect. Then, monoisotopic hBN was transferred to a gFET to fabricate the proposed device. The resistance of the device was observed to increase in correlation with the total thermal neutron flux. This change in resistance can be attributed to the interaction between the device and alpha particles generated from thermal neutron capture by Boron-10. The ability of this device to detect changes in resistance under neutron irradiation in real time may offer a significant advancement in ensuring astronaut safety by providing real-time monitoring of neutron exposure, which is a critical aspect of cosmic radiation.