Monte Carlo modelling the dosimetric effects of electrode material on diamond detectors

• Published in: Australasian physical & engineering sciences in medicine Vol. 38; no. 1; pp. 101 - 108
• Main Authors: Baluti, Florentina, Deloar, Hossain M., Lansley, Stuart P., Meyer, Juergen
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-03-2015; Springer Nature B.V
• Subjects: Biological and Medical Physics; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedical materials; Biomedicine; Biophysics; Computer Simulation; Diamond; Diamonds; Dosimetry; Electrodes; Medical and Radiation Physics; Models, Theoretical; Monte Carlo Method; Monte Carlo simulation; Radiation therapy; Radiometry; Reproducibility of Results; Scientific Paper; Radiotherapy dosimetry; Simulation interface; Electrode material; Monte Carlo; CVD diamond
• ISSN: 0158-9938; 1879-5447
• DOI: 10.1007/s13246-015-0329-6

Diamond detectors for radiation dosimetry were modelled using the EGSnrc Monte Carlo code to investigate the influence of electrode material and detector orientation on the absorbed dose. The small dimensions of the electrode/diamond/electrode detector structure required very thin voxels and the use of non-standard DOSXYZnrc Monte Carlo model parameters. The interface phenomena was investigated by simulating a 6 MV beam and detectors with different electrode materials, namely Al, Ag, Cu and Au, with thickens of 0.1 µm for the electrodes and 0.1 mm for the diamond, in both perpendicular and parallel detector orientation with regards to the incident beam. The smallest perturbations were observed for the parallel detector orientation and Al electrodes (Z = 13). In summary, EGSnrc Monte Carlo code is well suited for modelling small detector geometries. The Monte Carlo model developed is a useful tool to investigate the dosimetric effects caused by different electrode materials. To minimise perturbations cause by the detector electrodes, it is recommended that the electrodes should be made from a low-atomic number material and placed parallel to the beam direction.