enhancement of md-55-2 radiochromic film sensitivity using a multilayer film technique for applications in the low dose range

abstractbackgrounds: md-55-2 is one of the radiochromic film models with the sensitivity suitable for dose measurements ranging from 5 to 100 gy.  however, this lower limit makes the film impractical for its applications in many areas such as brachytherapy source dosimetry.materials and methods: in this project, the useful range of the film has been extended by using a multilayer film technique. in this technique, single-, double-, and triple- layers of films were exposed to the doses ranging from 0.5 to 10 gy using a co-60 photon beam. calibration curves for corresponding layers of films were obtained with a spectrophotometer using a 680nm wavelength.results: the results indicated that the sensitivities of double and triple layers were approximately 200% and 300%, respectively, higher than a single-layer film.  the impact of multilayer film arrangement on the energy dependence of the md-55-2 radiochromic film has also been examined using 100kvp, 80 kvp, and 6 mv x-ray beams. the results indicated an insignificant (within 5%) change in film responses with the beam energy. conclusion: therefore, the multilayer technique enhances the radiochromic film sensitivity and expands its application to the low dose range in field of brachytherapy source dosimetry.