Abstract

The validity of the photographic reciprocity law for alpha-rays has been confirmed for a ratio of source intensities of 171 to 1. The law had previously been confirmed for a ratio of source intensities of only 7 to 1. The source intensities used were equivalent to 1.38 millicuries/cm² and 8.06×10⁻³ millicurie/cm². The reciprocity law is found to hold for this ratio of source intensities when the exposures are made in a sequence which eliminates the effect of latent image growth. To avoid complications due to aggregate recoil the sources were coated with a layer of silver approximately 0.1μ in thickness.

© 1936 Optical Society of America

The Effect of Temperature upon Reciprocity Law Failure in Photographic Exposure*

J. H. Webb
J. Opt. Soc. Am. 25(1) 4-23 (1935)

The Response of a Photographic Emulsion to Alpha-Rays

T. R. Wilkins and R. N. Wolfe
J. Opt. Soc. Am. 23(9) 324-332 (1933)

The Failure of the Photographic Reciprocity Law at Low Intensity*

J. H. Webb and C. H. Evans
J. Opt. Soc. Am. 28(11) 431-436 (1938)

The Summation of Different Color Radiations by a Photographic Emulsion*†

J. H. Webb
J. Opt. Soc. Am. 26(1) 12-23 (1936)

The Photographic Reciprocity Law at Low Temperature*

C. H. Evans and E. Hirschlaff
J. Opt. Soc. Am. 29(4) 164-167 (1939)