Abstract
Abstract This research describes chemical dosimeter, and the aims of this study are Fricke dosimeter and TiO2 sol dosimeter individually. In Fricke dosimeter, the main work is to set up a calibration system for gamma radiation at low dose, and to confer the influence of environmental temperature. Another main work is the feasibility to establish the ultraviolet radiation measurement system with the TiO2 sol solution. The Fricke dosimeter also called the ferrous sulfate dosimeter is the most useful chemical dosimeter. The principle is the oxidation of ferrous ions (Fe2+) to ferric ions (Fe3+) by 60Co γ-radiation. The absorbed dose of the irradiated Fricke dosimeter can be determined by measurement of the concentration change of Fe3+. It may be an application in γ-radiation dosimeter due to a linear relationship between the absorption intensity of Fe3+ and absorbed dose of γ-radiation. It is useable in the dose range of 30-400 Gy traditionally. In this study, the main dose ranged between 5-30 Gy in Fricke dosimeter is investigated and the stability and reproducibility are also tested. In addition, a concentrated TiO2 sol dosimeter which is sensitive to UV-radiation is prepared in this study. The synthesis of TiO2 sols was performed by hydrolysis of titanium isopropoxide adding to the mixture solution of ethyl alcohol (as dispersing solvent) and hydrochloric acid. After aging, TiO2 sols were irradiated under UV radiation the color of TiO2 sols changed from colorless to deep blue with a characteristic absorption around 580 nm. There is a linear relationship between the absorption intensity and absorbed dose of UV radiation. The influence of particle size distribution in different concentrated TiO2 sol dosimeters is studied. The parameters in TiO2 sol dosimeter are conferred in order to find the optimum concentration. Keywords: Chemical dosimeter; Fricke dosimeter; TiO2 sol dosimeter