title: Characterization of a synthetic single crystal diamond Schottky diode for radiotherapy electron beam dosimetry.
abstract: OBJECTIVE
  To investigate the dosimetric properties of synthetic single crystal diamond based Schottky diodes under irradiation with therapeutic electron beams from linear accelerators.
  
  
  METHODS
  A single crystal diamond detector was fabricated and tested under 6, 8, 10, 12, and 15 MeV electron beams. The detector performances were evaluated using three types of commercial detectors as reference dosimeters: an Advanced Markus plane parallel ionization chamber, a Semiflex cylindrical ionization chamber, and a p-type silicon detector. Preirradiation, linearity with dose, dose rate dependence, output factors, lateral field profiles, and percentage depth dose profiles were investigated and discussed.
  
  
  RESULTS
  During preirradiation the diamond detector signal shows a weak decrease within 0.7% with respect to the plateau value and a final signal stability of 0.1% (1σ) is observed after about 5 Gy. A good linear behavior of the detector response as a function of the delivered dose is observed with deviations below ±0.3% in the dose range from 0.02 to 10 Gy. In addition, the detector response is dose rate independent, with deviations below 0.3% in the investigated dose rate range from 0.17 to 5.45 Gy∕min. Percentage depth dose curves obtained from the diamond detector are in good agreement with the ones from the reference dosimeters. Lateral beam profile measurements show an overall good agreement among detectors, taking into account their respective geometrical features. The spatial resolution of solid state detectors is confirmed to be better than that of ionization chambers, being the one from the diamond detector comparable to that of the silicon diode. A good agreement within experimental uncertainties was also found in terms of output factor measurements between the diamond detector and reference dosimeters.
  
  
  CONCLUSIONS
  The observed dosimetric properties indicate that the tested diamond detector is a suitable candidate for clinical electron beam dosimetry.
authors: Dipartimento di Ingegneria Industriale, Università di Roma Tor Vergata, Roma, Italy.
authors: C
authors: C
authors: Di Venanzio
authors: Marco
authors: M
authors: Marinelli
authors: E
authors: E
authors: Milani
authors: G
authors: G
authors: Prestopino
authors: C
authors: C
authors: Verona
authors: G
authors: G
authors: Verona-Rinati
authors: M D
authors: MD
authors: Falco
authors: P
authors: P
authors: Bagalà
authors: R
authors: R
authors: Santoni
authors: M
authors: M
authors: Pimpinella
mesh_terms: D018130:Diamond / Q000737:chemistry*; D004566:Electrodes; D004583:Electrons; D011829:Radiation Dosage; D011874:Radiometry; D011878:Radiotherapy / Q000295:instrumentation*
chemical_list: D018130:Diamond