Monte Carlo and experimental relative dose determination for an Iridium-192 source in water phantom

Background: monte carlo and experimental relative dose determination in a water phantom, due to a high dose rate (hdr) ^192ir source is presented for real energy spectrum and monochromatic at 356 kev. materials and methods: the dose distribution has been calculated around the ^192ir located in the center of 30 cm ×30 cm ×30 cm water phantom using mcnp4c code by monte carlo method. relative dose variation has been measured by using gafchromic rtqa along x and y axis, as well. percentage depth dose (pdd) variation along the different axis parallel and perpendicular the source were calculated. finally, f (5cm, θ|) dosimetry parameters of tg-43 protocol were determined. results: the results showed that the monte carlo method could calculate dose deposition in high gradient region, near the source, accurately. the isodose curves and dosimetric characteristics obtained for ^192ir source are in good agreement with experimental results. conclusion: the isodose curves of the ^192ir source were derived form dose calculation by mcnp code. also, monte carlo and experimental pdd x=2.5 mm are in good agreement, and the both results y=10 mm, in x ∈[-25mm,25mm] interval were well matched. however, out of this range monte carlo result was estimated to be lower. the calculated dosimetry parameters for the source were in agreement with other results.