An investigation into the dose rate and photon energy dependence of the GENA gel dosimeter in the MeV range

Abstract

PurposeIn the current study, the energy and dose rate dependence of a new genipin-based gel dosimeter, named GENA gel dosimeter, were investigated. MethodsPrepared gel dosimeters exposed using a Varian clinical linac. Beam qualities of 6 and 18 MV were applied to investigate the GENA gel dosimeter’s energy dependence. Furthermore, the gel dosimeters were exposed to 50, 100, 200, and 350 cGy/min dose rates, ranging from 0 to 8 Gy. The irradiated gel dosimeters were read out using a double beam UV–Visible spectrophotometer. The absorbance peak (AP) and area under spectrum (AUS) were evaluated. ResultsAbsorbance-dose sensitivities of (8.0 ± 0.18) × 10–3 cm–1Gy−1 and (7.8 ± 0.15) × 10–3 cm−1Gy−1 were obtained for GENA gel dosimeter for 6 and 18 MV beam qualities, respectively. Results specified no significant difference (p > 0.05) between the GENA gel dosimeter’s sensitivities irradiated using the two energies mentioned above. For the mentioned dose rates, AP-dose sensitivities of (8.2 ± 0.22) × 10−3, (8.1 ± 0.21) × 10−3, (8.1 ± 0.2) × 10−3 and (8.0 ± 0.18) × 10−3 cm−1Gy−1 were obtained, respectively. Results showed no significant difference (p > 0.05) between the GENA gel dosimeter’s sensitivities for the investigated dose rates and energies. In addition, results revealed that when the incident photon energy and dose rate changed, there were no significant differences (p > 0.05) between the GENA gel dosimeter’s dose resolution values. ConclusionsIt is concluded that the response of the GENA gel dosimeter is not dependent on the energy and dose rate (p > 0.05) within the studied energy and dose rate ranges.