Evaluation of Linearity for the Radiophotoluminescence Glass Dosimeter Based on Monochromatic X-rays

• Published in: Igaku butsuri : Nihon Igaku Butsuri Gakkai kikanshi = Japanese journal of medical physics : an official journal of Japan Society of Medical Physics Vol. 20; no. 4; pp. 151 - 158
• Main Authors: Shimozato, Tomohiro, Tamiya, Tadashi, Tabushi, Katsuyoshi, Koyama, Shuji, Yoshioka, Setsu, Obata, Yasunori, Tsuzaka, Masatoshi, Narita, Norihiko, Uruga, Tomoya, Ban, Shuichi, Namito, Yoshihito, Ikegami, Toru
• Format: Journal Article
• Language: English
• Published: Japan Japan Society of Medical Physics 2000
• Subjects: dose equivalent; linearity; monochromatic X-ray; personal radiation; radiophotoluminescence glass dosimeter
• ISSN: 1345-5354; 2186-9634
• DOI: 10.11323/jjmp2000.20.4_151

Although low energy X-rays have been utilized for mammography, their safety in medical use is a matter of concern. Characteristics of the radiophotoluminescence glass dosimeter, GD-403, consisting of a glass element and filters, were investigated with respect to monochromatic X-rays obtained from a synchrotron radiation for personal monitoring of low energy photons. We focused on low energy X-rays ranging from 8 to 20keV to study the linearity of the GD-403 response between photon fluence and dose equivalent. The GD-403 was placed on a tough water phantom and irradiated using an 11-15mm×0.1-7mm beam for modulation of the photon fluence. The tough water phantom could be moved through a distance of 110-150mm with a stepping motor. For the dose equivalent at 1 cm depth (H1),3mm (H3) and 70, μm (H70), the GD-403 showed sufficient linearities against the photon fluences in the energy regions of 8 to 20keV,13 to 20 keV and 13 to 20 keV, respectively. However, H3 and H70 did not provide sufficient linearities in the energy region of 8 to 12 keV. Moreover, we compared the result in this experiment with the value calculated from the absorbed dose of air using the mass absorption coefficient for the X-ray energy ranging from 10to 20keV.