The Response of a Photographic Emulsion to Alpha-Rays
T. R. Wilkins, R. N. Wolfe · Journal of the Optical Society of America · 1933
The equation D=Dmax(1−e−c1N) developed by Kinoshita for single-layer emulsions has been shown to hold for commercial emulsions. A derivation of this formula is given which shows that the probability constant c1 should be the same for thick as for thin emulsions. A useful relation s0=k/πρ2 between s0, the number of grains under a sq. cm of emulsion surface, k, the number of grains in the depth of the emulsion, and πρ2, the average grain size has been deduced and tested. To eliminate the density due to fluorescence, chromic acid desensitization has been used. Photographic effects due to mechanical pressure have on these desensitized plates, been found to be reversed by alpha-rays as well as by the other radiations previously reported. Average grain-size measured microscopically=0.14μ2πρ2 from desensitized plate No. 93=0.08πρ2 from desensitized plate No. 100=0.12πρ2 from s0=k/πρ2=0.12Chromic acid desensitization has been found to be effective only for a limited time.