Evaluation of a ferrous benzoic xylenol orange transparent PVA cryogel radiochromic dosimeter

A stable cryogel dosimeter was prepared using ferrous benzoic xylenol orange (FBX) in a transparent poly-(vinyl alcohol) (PVA) cryogel matrix. Dose response was evaluated for different numbers of freeze-thaw cycles (FTCs), different concentrations of PVA, and ratios of water/dimethyl sulfoxide. Linear relationships between dose and absorbance were obtained in the range of 0-1000 cGy for all formulations. Increasing the concentration of PVA and number of FTCs resulted in increased absorbance and sensitivity. The effects of energy and dose rate were also evaluated. No significant dose rate dependence was observed over the range 1.05 to 6.33 Gy min(-1). No energy response was observed over photon energies of 6, 10, and 18 MV.