Silicon Carbide Detector in Microbeam and Broad Beam Synchrotron Radiation Fields

We assess the performance of a CMRP designed epitaxial Schottky Silicon Carbide (SiC) detector, produced by SINTEF (Norway), for Microbeam Radiation Therapy (MRT). For dosimetry, ideally the detector should have a response similar to that of human tissue, should have micron-scale spatial resolution and accurately determine the dose that the microbeams deliver in the Synchrotron X-Ray radiation field. The average measured width of the microbeams (defined by 50 μm wide slots in a multislit collimator) was 54 ± 1 μm. The percentage depth dose (PDD) curve measured using the SiC detector in solid water, in the centre of a 20 mm x 20 mm uniform irradiation field, was also obtained. The PDD from depths ranging from 5 mm to 60 mm for two different X-ray beam filtration conditions are compared to equivalent GEANT4 simulations. The average experiment-simulation difference for all depths studied was ±5.1 % for copper-copper filtration and ±2.1 % for aluminium-copper filtration. The results obtained for the SiC detector to accurately resolve microbeams, as well as measuring the PDD, is very encouraging, in these intense synchrotron microbeam fields.