Diamond has long been the material of interest for radiotherapy dosimetry due to its high sensitivity, radiation hardness and near tissue equivalency. However natural diamond detector has not become a popular choice because of variability among detectors, high cost and response dependence on dose rate. The recent success in synthesizing single crystal diamond has reignited the interest. Synthetic diamond is highly reproducible in purity and electrical properties, combined with small size, it is a suitable candidate for small field dosimetry. A newly available synthetic single crystal diamond detector is being studied to determine the basic dosimetric characteristic and applicability in small field dosimetry. A series of measurements were made in comparison with a 0.125c.c ionization chamber, and two diode detectors. Response of the diamond detector is independent on dose, dose rate and energy. The output factors of small fields determined by the diamond detector is lower than that of the diode detectors and higher than that of the ionization chamber which are known to over response and under response respectively. In percentage depth dose and beam profile measurements, the diamond detector performs similarly with the two diode detectors. It is found that the diamond detector is suitable for small field relative dosimetry. Further investigation is required to study the spatial resolution of the diamond detector in different measurement geometry and the suitability in determining percentage depth dose in the buildup region. / published_or_final_version / Diagnostic Radiology / Master / Master of Medical Sciences
| Identifer | oai:union.ndltd.org:HKU/oai:hub.hku.hk:10722/206504 |
| Date | January 2014 |
| Creators | Hui, Siu-kee, 許兆基 |
| Publisher | The University of Hong Kong (Pokfulam, Hong Kong) |
| Source Sets | Hong Kong University Theses |
| Language | English |
| Detected Language | English |
| Type | PG_Thesis |
| Rights | Creative Commons: Attribution 3.0 Hong Kong License, The author retains all proprietary rights, (such as patent rights) and the right to use in future works. |
| Relation | HKU Theses Online (HKUTO) |
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