The Energy Loss of Hydrogen, Helium, Nitrogen, and Neon Ions in Gases

Abstract

The rate of loss of energy of protons, deuterons, helium, nitrogen, and neon ions in the energy range of 150 to 450 kev has been measured in the gases hydrogen, helium, air, and argon. The ions were sent through a differentially pumped gas system and the energy loss in the forward direction due to the gas was determined with an electrostatic analyzer.The results for protons agree with recent measurements at the California Institute of Technology. At the same energy, the stopping cross sections are roughly the same for neon and helium ions. The stopping power for nitrogen ions is greater than that for neon ions of the same energy by a factor ranging from 1.3 to 1.9, illustrating the importance of external electron configurations in determining stopping powers in our energy region. With the exception of hydrogen gas, the cross sections for the heavier ions follow a power law. The dependence ranges from ${E}^{0.33}$ to ${E}^{0.59}$, depending on the gas and ion, with several of the curves following an ${E}^{\frac{1}{2}}$ power law.