Abstract: New compositions of tissue-equivalent three-dimensional polymer gel dosimeters based on acrylamide (AAm), N-isopropylacrylamide (NIPAM), N-(Hydroxymethyl)acrylamide (NHMA), diacetone acrylamide (DAAM) and N-Vinylcaprolactam (NVCL) monomer with ethylene glycol co-solvent have been introduced in this invention for radiotherapy dosimetry. The dosimeter was irradiated with 6 and 15 MV linear accelerator at absorbed doses up to 10 Gy. The nuclear magnetic resonance (NMR) spin-spin relaxation rate (R2) for water proton surrounding polymer formation was used to investigate the degree of polymerization of the five gels. The effect of additives, dose rate, radiation energy, stability of the polymerization after irradiation, were investigated on the dose response of the gels.

Abstract: Calcein-PVA film and Calcein solution dosimeters is made for high dose applications. Systematic evaluation of dosimetric properties for the films is being conducted and was found useful for routine dosimeter in industrial radiation processing. The color bleaching of CA-PVA film and CA solution increases gradually with increasing absorbed dose in the dose range of 5-30 kGy for film, and 0.25-1 kGy for solution. The dose sensitivity increases significantly with increase of concentration of CA dye. The response of the CA-PVA films was slightly affected by relative humidity and temperature. The stability of film dosimeters and solutions after irradiation was very high and were stable for up to 30 days.