Dosimetric characterization of a synthetic single crystal diamond detector in clinical radiation therapy small photon beams
- INFN-Dipartimento di Ingegneria Industriale, Universita di Roma 'Tor Vergata',Via del Politecnico 1, I-00133 Roma (Italy)
Purpose: To determine the potentialities of synthetic single crystal diamond Schottky diodes for accurate dose measurements in radiation therapy small photon beams. Methods: The dosimetric properties of a diamond-based detector were assessed by comparison with a reference microionization chamber. The diamond device was operated at zero bias voltage under irradiation with high-energy radiotherapic photon beams. The stability of the detector response and its dose and dose rate dependence were measured. Different square field sizes ranging from 1 Multiplication-Sign 1 cm{sup 2} to 10 Multiplication-Sign 10 cm{sup 2} were used during comparative dose distribution measurements by means of percentage depth dose curves (PDDs), lateral beam profiles, and output factors. The angular and temperature dependence of the diamond detector response were also studied. Results: The detector response shows a deviation from linearity of less than {+-}0.5% in the 0.01-7 Gy range and dose rate dependence below {+-}0.5% in the 1-6 Gy/min range. PDDs and output factors are in good agreement with those measured by the reference ionization chamber within 1%. No angular dependence is observed by rotating the detector along its axis, while {approx}3.5% maximum difference is measured by varying the radiation incidence angle in the polar direction. The temperature dependence was investigated as well and a {+-}0.2% variation of the detector response is found in the 18-40 Degree-Sign C range. Conclusions: The obtained results indicate the investigated synthetic diamond-based detector as a candidate for small field clinical radiation dosimetry in advanced radiation therapy techniques.
- OSTI ID:
- 22100649
- Journal Information:
- Medical Physics, Vol. 39, Issue 7; Other Information: (c) 2012 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-2405
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
60 APPLIED LIFE SCIENCES
BEAM PROFILES
DEPTH DOSE DISTRIBUTIONS
DIAMONDS
DOSE RATES
DOSIMETRY
GY RANGE 01-10
INCIDENCE ANGLE
IONIZATION CHAMBERS
IRRADIATION
MONOCRYSTALS
PHOTON BEAMS
RADIATION DOSES
RADIOTHERAPY
SCHOTTKY BARRIER DIODES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K