An assessment of radiotherapy dosimeters based on CVD grown diamond

Citation
S. Ramkumar et al., An assessment of radiotherapy dosimeters based on CVD grown diamond, NUCL INST A, 460(2-3), 2001, pp. 401-411
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences","Instrumentation & Measurement
Journal title
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
ISSN journal
0168-9002 → ACNP
Volume
460
Issue
2-3
Year of publication
2001
Pages
401 - 411
Database
ISI
SICI code
0168-9002(20010321)460:2-3<401:AAORDB>2.0.ZU;2-A
Abstract
Diamond is potentially a very suitable material for use as a dosimeter for radiotherapy. Its radiation hardness, the near tissue equivalence and chemi cal inertness are some of the characteristics of diamond, which make it wel l suited for its application as a dosimeter. Recent advances in the synthes is of diamond by chemical vapour deposition (CVD) technology have resulted in the improvement in the quality of material and increased its suitability for radiotherapy applications. We report in this paper. the response of pr ototype dosimeters based on two different types (CVD1 and CVD2) of CVD diam ond to X-rays. The diamond devices were assessed for sensitivity, dependenc e of response on dose and dose rate, and compared with a Scanditronix silic on photon diode and a PTW natural diamond dosimeter, The diamond devices of CVD1 type showed an initial increase in response with dose, which saturate s after approximate to 6 Gy. The diamond devices of CVD2 type had a respons e at low fields ( < 1162.8 V/cm) that was linear with dose and dose rate. A t high fields ( > 1 162.8 V/cm), the CVD2-type devices showed polarisation and dose-rate dependence. The sensitivity of the CVD diamond devices varied between 82 and 1300 nC/Gy depending upon the sample type and the applied v oltage. The sensitivity of CVD diamond devices was significantly higher tha n that of natural diamond and silicon dosimeters. The results suggest that CVD diamond devices can be fabricated for successful use in radiotherapy ap plications. (C) 2001 Elsevier Science B.V, All rights reserved.