LET Calibration of Ion Microbeams and Their SEE Cross Section Characterization

The Australian Nuclear Science and Technology Organisation hosts the Center for Accelerator Science, a sovereign facility with light and heavy ion beams. The 10-MV ANTARES accelerator is equipped with one of the few heavy ion nuclear microprobes in the world, which has been upgraded with the unique external beam irradiation facility (EBIF). EBIF has been actively used in the past few years for space radiation testing of electronics, advanced shielding materials, and living samples for life science in space. To align with international standards for such testing, a series of tests were performed to evaluate the uniformity of the raster scan of the microbeam across broad areas. Second, EBIF has been calibrated in terms of direct linear energy transfer (LET) measurement by using a silicon on insulator microdosimeter developed by the Centre for Medical Radiation Physics (CMRP), University of Wollongong. Third, in collaboration with researchers from European Organization for Nuclear Research (CERN), energy calibration and single-event effect (SEE) cross section measurements were performed with a silicon diode and a commercial static random-access memory (SRAM), which were evaluated in other international facilities. This article discusses experimental data obtained during the tests and their comparison with GEANT4 and stopping and range of ions in matter (SRIM) simulations.