Ranges and Stopping Cross Sections of Low-Energy Tritons

Stopping cross sections and ranges of tritons as a function of energy from {~}0.2 to 2.7 MeV have been measured in polystyrene, nitrogen, air, aluminum, argon, nickel, krypton, and xenon by a conicidence technique utilizing the Li⁶(n,α)H³ reaction. The ranges found for 2.736-MeV tritons in these materials are 6.12±{}0.10, 7.26±{}0.06, 7.34±{}0.06, 10.10±{}0.10, 11.40±{}0.09, 15.15±{}0.15, 17.83±{}0.18, and 20.36±{}0.20 mg/cm², respectively. Above EₜZ≈0.05, the atomic stopping cross section ε in eV-cm² is given ε×10¹⁵=4(EₜZ)^-1/2-(EₜZ)1/2, where Eₜ is the triton energy in MeV and Z is the atomic number of the absorber. The data are compared with stopping theories for the velocity region in which shell effects cause deviations from the simple higher energy stopping theory.