A novel synthetic single crystal diamond device for in vivo dosimetry. Issue 8 (13th July 2015)

• Record Type: Journal Article
• Authors: Marinelli, Marco; Prestopino, G.; Tonnetti, A.; Verona, C.; Verona‐Rinati, G.; Falco, M. D.; Bagalà, P.; Pimpinella, M.; Guerra, A. S.; De Coste, V.
• Is Part Of: Medical physics. Volume 42:Issue 8(2015)Part 1
• Page Start: 4636
• Page End: 4644
• Publication Date: 2015-07-13
• Subjects: biomedical equipment -- cobalt -- diamond -- dosimeters -- dosimetry -- photodiodes -- prototypes -- radiation therapy -- Schottky diodes; Dosimetry/exposure assessment -- Therapeutic applications, including brachytherapy -- Photodiodes; phototransistors; photoresistors -- Junction diodes; Radiation therapy -- Dosimeters -- Including semiconductor components sensitive to infra‐red radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation -- Semiconductor devices sensitive to infra‐red radiation, light, electromagnetic radiation of shorter wavelength, or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof -- Characterised by only one potential barrier or surface barrier -- Scintigraphy -- Diodes -- Schottky diodes; synthetic diamond dosimeter -- in vivo dosimetry -- radiation therapy -- semiconductor detectors; Dosimetry -- Particle beam detectors -- Diamond -- Photons -- Capacitors -- Elemental semiconductors -- Charged currents -- Schottky barriers -- Leak detectors; Medical physics -- Periodicals; Medical physics; Geneeskunde; Natuurkunde; Toepassingen; Biophysics; Periodicals; Periodicals; Electronic journals; 610.153
• DOI: 10.1118/1.4926556
• Languages: English
• ISSNs: 0094-2405

Abstract

Abstract : Purpose: Aim of the present work is to evaluate the synthetic single crystal diamond Schottky photodiode developed at the laboratories of "Tor Vergata" University in Rome in a new dosimeter configuration specifically designed for offline wireless in vivo dosimetry (IVD) applications. Methods: The new diamond based dosimeter, single crystal diamond detector (SCDD‐iv), consists of a small unwired detector and a small external reading unit that can be connected to commercial electrometers for getting the detector readout after irradiation. Two nominally identical SCDD‐iv dosimeter prototypes were fabricated and tested. A basic dosimetric characterization of detector performances relevant for IVD application was performed under irradiation with 60 Co and 6 MV photon beams. Preirradiation procedure, response stability, short and long term reproducibility, leakage charge, fading effect, linearity with dose, dose rate dependence, temperature dependence, and angular response were investigated. Results: The SCDD‐iv is simple, with no cables linked to the patient and the readout is immediate. The range of response with dose has been tested from 1 up to 12 Gy; the reading is independent of the accumulated dose and dose rate independent in the range between about 0.5 and 5 Gy/min; its temperature dependence is within 0.5% between 25 and 38 °C, and its directional dependence is within 2% from 0° to 90°. The combined relative standard uncertainty of absorbed dose to water measurements is estimated lower than the tolerance and action level of 5%. Conclusions: The reported results indicate the proposed novel offline dosimeter based on a synthetic single crystal diamond Schottky photodiode as a promising candidate for in vivo dosimetry applications with photon beams.