Effect of heavy ion irradiation on optical property of radiation-crosslinked hydroxypropyl cellulose gel containing methacrylate monomers

Effects of dose rate and liner energy transfer (LET) on the optical property of a polymer gel dosimeter irradiated with swift heavy ions were investigated. The polymer gel dosimeters that consist of 2-hydroxyethyl methacrylate, polyethylene glycol dimethacrylate, and tetrakis(hydroxymethyl)phosphonium chloride with radiation-crosslinked hydroxypropyl cellulose gel matrix were prepared. The dosimeters were irradiated with 150 MeV/u He ions, 290 MeV/u C ions, and 500 MeV/u Fe ions at HIMAC, and then were optically analyzed by using a UV–Vis spectrophotometer. Absorbance of the irradiated dosimeters increased with an increase in the dose up to 10 Gy. The absorbance at the dose of 5 Gy decreased with increasing dose rate in all of the heavy ions. The dosimeter irradiated with Fe ions exhibited the lowest dose response of the absorbance. It was found that the sensitivity of the dosimeters decreased with increasing dose rate as well as LET of the incident heavy ions.