The aim of this research is to develop the method to measure the absorbed dose for radiotherapy level in the range of 1-10 Gy using EPR dosimeter. The parameters for measuring the absorbed dose using EPR dosimeter consist of microwave power, modulation amplitude, ratio of time constant: conversion time and number of scans have been used in this study. The results showed that the optimal parameters for measuring the absorbed dose in the range of 1-10 Gy were in the following; microwave power was 3.15 MW, the modulation amplitude was 17 G, the time constant: conversion time ratio was 4:1 and the number of scans was 10. The coefficients of determination between the dose from 1 to 10 Gy and the EPR signal generated from the optimal parameters was 0.9995. The accuracy of the developed method was more than 99% when compare with the ASTM E1026 standard method. It can be concluded that the optimal parameters used in the developed method can be used to determine the absorbed dose for radiotherapy level.
Keywords: absorbed dose, radiotherapy level, EPR dosimeter