Microdensitometer system with micrometer resolution for reading radiochromic films

Abstract

Radiation dose deposited on a radiochromic film is considered as a dose image. A precise image extraction system with commensurate capabilities is required to measure the transmittance of the dose image and correlate it with radiation dose. The disclosed microdensitometer system is designed to achieve this goal according to the unique characteristics of the radiochromic films, namely (a) the linearity and sensitivity of the dose response of the radiochromic films being highly dependent on the wavelength of the analyzing light and (b) the inherently high spatial resolution of the radiocbromic films. The disclosed microdensitometer system consists of a monochromator which provides analyzing light of variable wavelength, a film holder on a high-precision scanning stage, a CCD-dedicated microscope in conjunction with a thermoelectrically cooled CCD camera, corresponding computer interfaces and a microcomputer.