Developing and Investigating the Response of an SRAM Dosimeter for Use in Radiation Effects Facilities

The Texas A&M University Cyclotron Institute’s Radiation Effects Facility (REF) provides researchers with heavy ion beams to test their electronics for use in terrestrial and aerospace applications. Reliable dosimetry is currently provided at the REF through the use of scintillator detectors, but a more mobile option would be beneficial to users at the REF and other facilities to verify their beams. A mobile dosimeter system using the response of an SRAM chip demonstrates total error cross section and multiplicity dependencies on linear energy transfer (LET), allowing for two distinct ways of characterizing the incident beam. In this project, improvements to the original dosimeter printed circuit board (PCB) were implemented, including a new mounting solution for quicker set-up, a reduction of electronic signal noise, and the ability to easily switch out the SRAM under test. The response of the redesigned dosimeter was tested using undegraded 40 MeV/u ⁷⁸Kr ions, which were also degraded to lower energies to obtain a series of LETs, to confirm its LET-dependent response. Part-to-part variation was also investigated by exposing multiple SRAM chips to the beam.