Plate 3.6. Explosion of a silver nucleus into 34 ionizing fragments by a cosmic ray. Trajectories of protons, deuterons, tritons. and alpha particles are emitted after the explosion. Fast mesons, also emitted cannot be seen due to insufficient sensitivity of the plate. The energy involved in this disintegration is more than 1 Bev. An Ilford C-2 plate. 100 microns thick, was used, exposed for three weeks on the Mont Blanc. At an altitude of 4,300 meters. Cosmic Ray Collision - Hit by a cosmic ray, a silver nucleus explodes into 34 ionising fragments. In this photograph, taken on a plate exposed for three weeks on Mont Blanc, trajectories of protons, deuterons, tritons and alpha particles can be seen. July 15, 1953.