PHOTOCHROMIC RADIATION DOSIMETER

1,228,295. Tenebrescent materials and uses thereof. UNITED STATES ATOMIC ENERGY COMMISSION. 18 Aug., 1969 [11 Sept., 1968], No. 41136/69. Heading C4S. [Also in Divisions C3 and H5] A film dosimeter material comprises a homogeneous mixture of a polyhalostyrene host and a leuco dye of the general formula wherein R is OH, OCH 3 , OC 2 H 5 or N 3 , each R1 is aryl, alkyl, alkoxy or is H, R11 is α-naphthyl, amino-phenyl, hydroxy-phenyl, or is H, and R111 is α-naphthyl, amino-phenyl or hydroxyphenyl. The host is preferably poly-3-chlorostyrene, poly-4-chlorostyrene, poly-4-bromostyrene, poly-4-iodoatyrene, orpoly-2,5-dichlorostyrene. The film dosimeter material may contain a metal organic compound, to vary the spectral sensitivity of the dye base, e.g. tetraphenylstannate, copper acetylacetonate and triphenyl bismuth. The film preferably contains 0À1 to 10% by weight of the dye and may be self-supporting having a thickness above 2 mils. Anthracene and phenanthrene may be present to reduce the film sensitivity. The liquid form may be used with suitable solvents for permanent or reversible coloration.