EVALUATION OF PROPRIETARY PHOTOCHROMIC SYSTEMS AND ANALYSIS OF DATA RELEVANT TO THE NUCLEAR FLASH PROTECTION PROGRAM.
Final rept. 1 Nov 64-31 Jan 66,
AMERICAN CYANAMID CO STAMFORD CT CENTRAL RESEARCH DIV
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This report contains extensive data on the degree of darkening, the rate of darkening time interval 0-100 microsec, and the rate of clearing time interval 10-20 millisec achieved by using flash excitation with certain proprietary photochromic, plastic samples that work by a mechanism involving triplet-triplet T-T absorption. Data on optical density per centimeter, values of triplet concentrations, and of T-T extinction coefficients achieved at several different energy inputs are shown for one-sided and two-sided excitation using several different matrices. The response is such that it can be estimated that a change in optical density of 3.0 can be effected throughout the entire visible spectrum in less than 100 microseconds by employing the near ultraviolet component from 300 to 420 millimicrons present in white light of color temperature 6200 K or higher when this exciting light consists of a quick flash with a rise time of 40 microseconds or less and when the total energy white light incident on the sample in a multisided mode of excitation is 0.03 calsq cm. It is also demonstrated that the same samples fade nearly exponentially, and lose 50 of the maximum color generated by the action of the flash in 1 sec. or less. When these same active agents are present in thin, concentrated plastic samples and are excited through only one broad face and from only one direction, incident total energy of white light estimated to be 0.037 calsq cm produces a change in optical density of only 1.0.
- Radiation and Nuclear Chemistry
- Nuclear Radiation Shielding, Protection and Safety