Investigations on the Effects of Neutron Irradiation on the Commercial 8051 Microcontroller

Neutron irradiation testing is becoming important for commercial-off-the-shelf (COTS) devices of the instrument and control (I&C) system while working in extreme environment applications where the risk of radiation is constant. This study exposes AT89C51RD2 8-bit high-performance flash microcontrollers by varying neutron fluence, assessing their resilience and vulnerabilities through in situ and ex situ experiments. Radiation tests were conducted with thermal and epithermal neutrons. Our results emphasize the importance of shielding, which shows greater resilience of the device in prolonging device lifespan, exhibiting fewer single-event upsets (SEUs) and better reliability in radiation-exposed environments. A single-event functional interrupt (SEFI) was observed during both in situ and ex situ experiments. During in situ experiments (thermal neutron irradiation), the failure was observed when the damage was ~10-8–10-7 dpa, whereas, during ex situ experiments (thermal and epithermal neutron irradiation), the performance of the microcontroller was affected when the damage is ~10-2 dpa. The reason for failure in the device could be due to damage produced by gamma rays (produced by induced activity) and displacement damage [by recoil and primary knock-on atoms (PKAs)]. The presence of 10B in the device, along with interactions with high-energy neutrons, can also lead to functional failures. However, overall findings suggest the potential for the device to develop robust systems in high-radiation environments, as it demonstrates the ability to withstand high neutron flux.