Range-Energy Relation for Protons in Nuclear Emulsions

An experimental range-energy relation in Ilford C-2 emulsion has been obtained for protons up to 39.5 Mev. In the region from 17 to 33 Mev the relation for dry emulsion is fitted by the empirical equation $E_{\left(\mathrm{Mev}\right)}=0.251\mathrm{}R_{\left(\mu \right)}^{}{}_{}{}^{0.581}$. Variations in water content due to changes in atmospheric humidity make several percent difference in range. The range in Ilford glass is found to be 18±4 percent longer than in dry C-2 emulsion.