Response of radiochromic films to UV irradiation

Radiochromic films containing a multi-arylamino methane compound were prepared, and their color changed from clear to green after irradiation under ultraviolet (UV) light. As the absorption spectrums show, the main absorption peak in the visual region locates around 626 nm, and there is a linear relationship between the response of optical density and radiation time. The response increases with UV light energy density enhancing. The response to fractioned irradiation is a little stronger than that to continuous irradiation. The response keeps constant at temperature of 20～50 ℃ and relative humidity 40%～60%. The sensitivity of the response is remarkably improved when halides are added into the radiochromic system. As the result of post-radiation effect, noteworthily, the response increas