A neutron detector using integrated circuits

With the advancements and miniaturization in semiconductor technology, the circuits within integrated circuits have become increasingly sensitive to the effects of radiation, and therefore, are susceptible to improper functioning in high radiation fields. The researchers at Texas A&M University have been able to manipulate this disadvantage into an advantage for radiation detection applications, by designing the radiation integrated circuit (RIC). The RIC consists of two regions, radiation-sensitive areas (RSAs) and radiationhardened areas (RHAs). To employ RICs for neutron detection purposes, a neutron reactive material is required to generate charged particles, which interact with the RSAs. This report presents the research and investigation carried out on natural boron (19.9% B), enriched boron (96% B), boron carbide (~75% B), and lithium fluoride (~24% Li) as the neutron-reactive coating. To do this, MCNPX (Monte Carlo N-Particle eXtended) simulations were performed, to assess the neutron detection performance of these coatings on the RICs. The analysis focused on determining the optimal yield of charged particles at the RIC-coating interface. In addition, a signal to noise (S/N) ratio was investigated that analyzed energy deposition from heavy charged particles (HCPs) compared to electrons. The highest yield of charged particles was tallied for the enriched boron, followed by boron carbide, lithium fluoride, and natural boron. For the 3-μm thick enriched boron coating, the highest yield of charged particles was estimated entering the RIC to interact with the RSAs. With this optimal thickness of enriched boron, HCPs deposited three orders of magnitude more energy than electrons. This indicated the noise created from electrons interactions would be insignificant compared to the signal produced by the HCPs.