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The purpose of this paper is to evaluate the dosimetric properties of N-(3-methoxypropyl) acrylamide (NMPA) polymer gel dosimeter using UV-vis spectrophotometry as a simple and low-cost method.

The gel samples have been irradiated to various doses using a medical linear accelerator with 6 MV beam energy. The optical density of un-irradiated and irradiated NMPA polymer gel dosimeters in terms of absorbance at 500 nm was investigated by UV-vis spectrophotometry.

The absorbance values of the gel samples were increased linearly with increasing dose in the dose range between 2 and 20 Gy. A remarkable improvement in the dose response was noticed after the addition of various concentrations of glycerol. The impact of dose rate, beam energy and the post-stability of the exposed gels was studied and found consistent with the previous study using nuclear magnetic resonance results (energy independent and dose rate independent, stable up to one week).

The results of the independent experimental spectrophotometry and nuclear magnetic resonance analyses indicate that the NMPA polymer gel dosimeter has good and consistent dosimetric features for radiotherapy dosimetry.

The ionizing radiation-induced polymerization of gel samples leads to a change in the absorbance of the irradiated gel samples. This study introduces the first characterization of NMPA gel dosimeter by means of UV-vis spectrophotometer.

The purpose of this paper is to present a radiochromic film dosimeter containing polyvinyl alcohol (PVA) matrix and various concentrations of methyl red (MR) dye for high dose measurements.

The MR-PVA films were exposed to irradiation up to 60 kGy using ⁶⁰Co source of gamma ray. The ultraviolet and visible regions (UV/VIS) spectrophotometry were used to examine the optical density of pre-and post-irradiated dosimeters at 424 nm.

The dose sensitivity of MR-PVA films increases significantly with increasing MR dye concentrations in the dose range of 5 to 60 kGy. The impact of relative humidity, irradiation temperature, dose rate and the stability of the films has been analyzed. The overall uncertainty of the MR-PVA film dosimeter is 6.12% (Double Standard-deviation, 95% confidence level).

It was found that the MR-PVA films may be used as high dose dosimeter with an acceptable overall uncertainty in routine industrial radiation processing.

The color bleaching of irradiated MR-PVA films in terms of specific absorbance curves increases significantly with increasing absorbed dose up to 60 kGy.