Design of SRAM Based Dosimetry Used for Neutron and Proton Detection

Abstract

Radiation causes soft errors in memory devices, and a variety of research has been focused on techniques to reduce these soft errors. In this thesis, instead of mitigating soft errors, we present an SRAM based dosimeter which uses the soft error susceptible nature of SRAMs as a means of measuring radiation fluence. This cost effective, real-time dosimeter can be used to calibrate and characterize neutron and proton beams with wide-range spectra. The design of the SRAM dosimeter includes both hardware and software. An array of thirty 16-Mbit off-the-shelf 65 nm SRAMs are used as sensors directly exposed to radiation. An FPGA is used as a processor to analyze the sensor data and communicate with a PC. Finally, a graphical user interface is provided for interacting with the dosimeter. The dosimeter device has been validated at the TRIUMF proton and neutron irradiation facility, and has been used by the facility to carry out various calibration and measurement activities such as proton and neutron beam characterization, beam profile measurements, collimator design and shielding effects measurements.