Basic characteristics of an AQUAJOINT®-based VIPET polymer gel dosimeter

The basic characteristics of a VIPET-type polymer gel dosimeter were assessed using AQUAJOINT® as a hydrogel matrix. The dosimeter exhibited a good dose response. The threshold dose was 0.5–0.6 Gy and the linear section of the response curve, in the range of 1.7 – 2.7 Gy, had a minimum dose response of 0.05–0.06 Gy. The dose-rate dependence was determined by the delivery of 200 MU for dose rates between 100 and 600 MU/min; the resulting value of R2 was 3.222 ± 0.036 (mean ± 1SD). A slight change in the value of R2 in the integration of the divided doses was observed; the R2 value was 3.059 ± 0.015 (mean ± 1SD) for a total irradiation of 200 MU. Gel samples of different volumes were irradiated and compared with a PAGAT polymer gel. The change in sensitivity of the AQUAJOINT®-based VIPET was smaller than that of the PAGAT. (paper)