(γ, p + α) REACTIONS PRODUCED IN PHOTOGRAPHIC EMULSIONS

Abstract

Ilford C.2 plates were exposed to bremsstrahlung of maximum energy 70 Mev. from the electron synchrotron at Queen's University, and 82 stars produced in the emulsion have been attributed to the reaction:[Formula: see text]The excitation function of the reaction shows a sharp drop near 40 Mev. and the integrated cross-section up to this limit has been estimated. In addition 23 stars have been identified as being due to the reaction:[Formula: see text]In both reactions the most probable mode of disintegration is by the initial emission of an alpha-particle. The range measurements in the carbon stars have been used to derive an accurate range–energy relation for lithium ions in nuclear emulsion.