NUKLEONIKA 2012, 57(4):491-495

 


DOSIMETRIC CHARACTERISTICS OF ACTIVE SOLID STATE DETECTORS IN A 60 MeV PROTON RADIOTHERAPY BEAM



Urszula Sowa, Tomasz Nowak, Barbara Michalec, Gabriela Mierzwińska, Jan Swakoń, Paweł Olko

Proton Radiotherapy Group,
The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN),
152 Radzikowskiego Str., 31-342 Kraków, Poland,



Several solid state detectors, such as dosimetric diodes, MOSFET detectors or diamond detectors are used for quality control of radiotherapy beams. The goal of this work was to determine dosimetric properties of the PTW diamond detector (DD) and the PTW silicon diode in the 60 MeV therapeutic beam (practical range in water Rp = 29.17 mm) located at the Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN, Kraków). A PTW Markus ionization chamber was used as a reference device. The empirical correction factor for diamond detector, kDD(Rresidual), introduced in the Technical Report Series of IAEA, TRS-398 [9] as a function of beam quality, Rresidual, was found to decrease from 1.12 for Rresidual = 1.5 mm to 1.04 for Rresidual = 26 mm. The reproducibility of response of DD and PTW diodes in the proton filed did not exceed 0.11%. Our results show that diamond detectors and dosimetric diodes are useful tools for quality assurance (QA) of therapeutic proton beam, but each type of detectors has specific properties which should be taken into account when choosing particular application.


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