Program Information

Characterization of a New Commercial Single Crystal Diamond Detector in Photon, Electron and Proton Beams

Y Akino

Y Akino*, I Das , Indiana University School of Medicine, Indianapolis, IN

Presentations

SU-F-BRE-2 Sunday 4:00PM - 6:00PM Room: Ballroom E

Purpose: Diamond detectors even with superior characteristics have become obsolete due to poor design, selection of crystal and cost. Recently, microDiamond using synthetic single crystal diamond detector (SCDD) is commercially available which is characterized in various radiation beams in this study.

Methods: The characteristics of a commercial SCDD model 60019 (PTW) to a 6- and 15-MV photon beams, 6- and 20-MeV electron beams, and 208 MeV proton beams were investigated and compared to the pre-characterized detectors: TN31010 (0.125 cm³) and TN30006 (pinpoint) ionization chambers (PTW), EDGE detector (Sun Nuclear Corp), and SFD Stereotactic Dosimetry Diode Detector (IBA). The depth-dose and profiles data were collected for various field sizes and depths. The dose linearity and dose rate dependency were also evaluated. To evaluate the effects of the pre-irradiation, the diamond detector which had not been irradiated on the day was set up in the water tank and the response to 100 MU was measured every 20 s. The temperature dependency was tested for the range of 4-60 °C. Angular dependency was evaluated in water phantom by rotating the SCDD.

Results: For all radiation types and field sizes, the depth-dose data of the diamond chamber showed identical curve to those of ionization chambers. The profile of the diamond detector was very similar to those of the Edge and SFD detectors, although the 0.125 cm³ and pinpoint chambers showed averaging effects in the penumbrae region. The temperature dependency was within 0.7% in the range of 4-41°C. A dose of 900 cGy and 1200 cGy were needed to stabilize the chamber to the level within 0.5% and 0.2%, respectively.

Conclusion: The type 60019 SCDD detector showed suitable characteristics for depth-dose and profile measurements for wide range of field sizes. However, at least 1000 cGy of pre-irradiation is needed for accurate measurements.


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