Abstract
The absorption spectra of the EBT2 film's components were investigated in conjunction with its use for UVA dosimetry. The polyester (topside) and adhesive layers of the EBT2 film have been gently removed. Gafchromic (TM) EBT2 films with and without the protected layers (polyester and adhesive) were exposed to UVR of 365 nm for different durations. Thereafter, the UV-visible spectra were measured using a UV - visible spectrophotometer (Model Spectro Dual Split Beam, UVS-2700). Films were digitized using a Nikon CanoScan 9000F Mark II flatbed scanner. The dosimetric characteristics including film's uniformity, reproducibility and post-irradiation development were investigated. The color development of EBT2 and new modified EBT2 (EBT2-M) films irradiated with UVA was relatively stable (less than 1%) immediately after exposure. Based on this study, the sensitivity of EBT2 to UVR with wavelength between similar to 350 nm and similar to 390 nm can significantly be enhanced if the adhesive layer (similar to 25 mu m) is removed. The polyester layer plays almost no part on absorbing UVR with wavelength between similar to 320 nm and similar to 390 nm. Furthermore, various sensitivities for the EBT2-M film has been established depending on the wavelength of analysis. (C) 2016 Elsevier Ltd. All rights reserved.