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, designed by SINTEF (Norway), for Microbeam Radiation Therapy (MRT). For dosimetry, ideally the detector should have 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 um wide slots in a multislit collimator) was 54 +/- 1 um. 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 tow 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.