THE DENSITOMETRIC RESPONSE OF THE HIGH SENSITIVE GAFCHROMIC FILM EXPOSED TO X-RAYS

Tests have been performed on the high sensitive (HS) GAFChromic film to evaluate its densitometric response to external X-rays (photon beam). Several 2 cm by 2 cm pieces of HS and MD-55-2 GAFChromic films were prepared and irradiated for sensitivity comparison, and X-rays energy dependence study. The optical densities of three irradiated pieces of HS film were measured as a function of time to establish the time taken for the optical density to stabilize. The densitometric sensitivity curves comparison showed that the HS film is twice as sensitive as its predecessor, MD-55-2, more spatially uniform and dosimetric measurements can be made with high precision. Its sensitivity is independent of 6 MV and 15 MV X-ray beam energies and its optical density is stable after about 36 hours post-irradiation time.