Study on a Radiochromic Gel Dosimeter

• Main Authors: Yu, Yi-Chen, 余宜宸
• Other Authors: Hsieh, Ling-Ling
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/99207455629520397595

碩士 === 中臺科技大學 === 醫學影像暨放射科學系暨研究所 === 102 === 　In this study, the Taguchi statistical method was used to design experiments for investigating the effects of interactions among compositions on the performance of a Turnbull blue gel (TBG) radiochromic dosimeter. Four parameters were considered as the design factors: (A) concentration of ferric chloride (B) concentration of potassium ferricyanide, (C) concentration of sulfuric acid, and (D) amount of gelling agent added. Two levels were selected for each factor. The change in optical absorbance at 695 nm under UVA exposures was monitored to determine the response of the dosimeters. The results showed that the contributions of factors A to D were 20.01%, 23.16%, 27.03%, and 0.49%, respectively. The contributions of significant interaction effects were AC (8.60%), BC (5.61%), and ABC (10.56%). This finding indicated that sulfuric acid (C) was the most influential factor whereas gelling agent (D) was the least influential factor. Sulfuric acid had an important function in two two-way interactions and one three-way interaction in the response of TBG to UV exposure. From the results showed that the 1.23 mM ferric chloride, 1.21 mM potassium ferricyanide, 1 mM sulfuric acid and 0.25% w/mL agarose were the best concentration of the TBG radiochromic dosimeter, linearity up to 0.9988 and sensitivity of 0.3491. The observation on diffusion showed that the dosimeter tended to be stable an hour after irradiated, with diffusion coefficient of 0.1181 mm2/h.