Radiological instrument

Abstract

A radiological measuring instrument including an angularly variable radiation sensitive structure comprised of two blocks of material having a different index of refraction with one of the materials comprising a radiochromic substance whose refractive index changes through anomolous dispersion as a result of being exposed to radiation. The ratio of the two indices of refraction is selected to be close to unity, with the radiation sensitive structure being pivotally adjusted so that light is directed into one end of the block comprising a material having the greater index of refraction. This element, moreover, is selected to be clear and transparent with the incident angle being close to the critical angle where total reflection of all incident light occurs. A portion of the incident light is furthermore projected through the clear transparent block without reflection, with the two beams emerging from the other end of the block, where they are detected. Exposure to radiation changes the index of refraction of the radiochromic block and accordingly the reflected energy emerging therefrom. Calibrated readjustment of the angle of incidence provides a measure of the sensed radiation.