اثرغلظت‌های مختلف ژلاتین در دز 36 گری پرتوهای گاما بر پارامترهای فراصوتی ژل پلیمر MAGIC-f

The aim of this study is to evaluate the effect of edible gelatin concentration as a polymerization agent on MAGIC-f polymer gel dose-response sensitivity irradiated by 1.25 MeV energy of cobalt-60. To investigate the dose-dependent polymerization, ultrasonic parameters of propagation speed of sound and broadband ultrasound attenuation coefficient were evaluated. To read-out of the radiation-induced polymerization of gel, ultrasonic parameters of speed of sound and broadband ultrasound attenuation coefficient before and after irradiation in 36 Gy absorbed dose were obtained using ultrasonic wave transmission technique at a frequency of 0.5 MHz, 24 hours after irradiation at 25 read-out temperature. To evaluate the gelatin concentration effect on gel polymerization, MAGIC-f polymer gel sensitivity were investigated in different concentrations of gelatin from 4 to 20 percent in steps of 2. The gelatin concentration with a maximum sensitivity of ultrasonic at dose of 36 Gy was determined utilizing t-test analysis. MAGIC-f polymer gel dosimeters response was optimized at 14 percent gelatin concentration, beyond which saturation happens. The most difference in absolute speed of sound and broadband ultrasound attenuation coefficient is related to 14% gelatin concentration, before and after 36 Gy irradiation was observed to be 21.9 &plusmn;1.7 m.s-1 and 49.6 &plusmn; 4/7 dB.MHz-1.cm-1, respectively (P <0.05). The sensitivity of dosimeters based on methacrylic acid depends on the gelatin concentration. In this study, 14% gelatin concentration showed the most polymerization. In addition, edible gelatin can be considered as an alternative to commercial gelatins. Ultrasound wave has the capability to be used as a readout method for polymer gel dosimeters.