Energy Loss of α Particles in Noble Gases from 0.3 to 2.0 MeV

Abstract

Stopping cross sections of gaseous He, Ne, Ar, Kr, and Xe for $\alpha$ particles of 300 keV to 2 MeV have been measured in a differentially pumped gas cell and checked in a sealed gas cell. The results agree with Weyl's measurements in He from 1 to 5%, with Weyl's measurements in Ar from 4.7 to 6.9%, and with Bichsel's measurements in Ar from - 2.8 to + 5.5%. The measurements agree over the entire energy region for all gases except He to better than 16% with the Lindhard-Winther theory modified by a Hartree-Fock-Slater electron charge distribution, and to better than 24% with Bonderup's theory with the same modification.