2018 Volume 81 Issue 1 Pages 53-64
The enhancement of the efficiency of latent image formation is essentially important for high-speed silver halide (AgX) emulsions including current nuclear emulsions. However, it is necessary to depress the efficiency of latent image formation for the detection of dark matters (DMs), since DMs create as many as 〜1000 electron-hole pairs/ grain with diameter of 〜40 nm. For this purpose, the guiding principles for the nuclear emulsion to detect DMs have been proposed by applying to it for the first time the concept of the detective quantum efficiency with three requisites (efficiency of latent image formation, gradation, and noise). Some experimental results of the examination of the proposed guiding principles are described for the present by use of nuclear emulsions with 〜40 nm AgX grains.
