Radiation Hardened Electronics for Reactor Environments

Considerations of Radiation-Hardened Electronics for Alpha Detectors in Molten Salt Reactors

“…The information in these tables addresses the maximum limits of these devices: not all devices in a category will survive these limits, and not all will be useful for every application. More information on device physics, radiation failure mechanisms, and limits can be found in the literature [14,15]. Variations in threshold voltage and leakage currents…”

Development of a Radiation-Tolerant Front End Digitizer

“…In non-nuclear applications, sensor signal pre-amplification and digitization occur as close as possible to the physical sensor mechanism to maintain signal fidelity. However, the high-temperature and high-radiation environment present in and around nuclear reactors has been shown to quickly damage electronics [3]. Solid-state semiconductor transistors are the most common point of failure of electronic circuits in high-radiation environments.…”

“…Field effect transistors are sensitive to the charges produced by ionizing radiation. These charges often become trapped in the forbidden gap in insulators, leading to errant operation of the transistors, such as threshold voltage and transconductance variations [3,4]. In large ionizing radiation fluxes, the sudden surge of charges produced and trapped by the incident particles leads to erroneous bit-flip errors in digital logic devices, which are known as single-event effects, single-event upsets, and single-event latchups [4].…”

“…Failures occurring at neutron fluences of 10 5 -10 9 n/cm 2 are common for these devices, though the specific mechanisms leading to these failure modes are still active research fields [8][9][10][11][12]. In contrast, junction-gate field-effect transistors (JFETs) are extremely insensitive to ionizing radiation due to the absence of an insulating gate and limited interfering surface effects typically created by insulating overlays [3,4,13]. Though they are niche in modern electronics, JFETs have been shown to be resistant to > 1 MGy (Si) irradiation [13][14][15][16].…”

“…The AFE of FREND was designed using low-cost, discrete JFETs for the proof-of-principle prototype design described here. However, the silicon-based JFETs chosen are unverified under neutron irradiation and are not expected to exceed the state-of-the-art neutron fluence limit of 10 14 -10 15 n/cm 2 [3]. It is feasible to increase this limit by switching to a wide bandgap semiconductor material and increasing the dopant levels [3,21] or positioning the FREND system further from the radiation source to extend it's operational lifetime.…”