Tissue-Equivalent Radiation Dosimeter-On-A-Chip

Many commercially available digital dosimeters are bulky and are unable to properly measure dose for space radiation. The complexity of space flight design requires reliable, fault-tolerant equipment with the capability of providing real-time dose readings during a mission, which is not feasible with the existing thermo-luminescent dosimeter (TLD) technology. The project will create a compact, lightweight, energy-efficient dose meter comprised of a tissue-equivalent scintillation crystal coupled to a solid-state photomultiplier (SSPM), which is an array of CMOS photodiodes, operated in Geiger avalanche mode. The ubiquitous nature of CMOS technology provides a standardized development platform, and the ability to integrate all the supporting electronics into a miniature, simple design. In Phase I, we will model the expected dosimeter performance and characterize the performance of a prototype dosimeter exposed to high-energy protons, which simulates radiation in the space environment. We will also determine the TLD-dose equivalence of our measurements. In Phase II, we will create the support software and design and fabricate a finalized chip that includes readout electronics, power supply, memory storage, and other interfacing components.