Stopping powers of the noble gases for (0.3-10)-MeV nitrogen ions.

Abstract

Stopping powers of the noble gases for 300-keV to 10-MeV nitrogen ions were measured using a time-of-flight technique. The stopping power was directly determined from changes in ion time of flight over a fixed distance as a function of the target-gas pressure of a differentially pumped, windowless gas cell. The measured stopping-power values are compared to predictions of the modified Firsov theory of Land and Brennan (FLB) [At. Data Nucl. Data Tables 22, 235 (1978)] and to values compiled by Ziegler et al. [Stopping and Range of Ions in Solids (Pergamon, New York, 1985)]. The measured values are close to the FLB values at v=${\mathit{v}}_{0}$ for low target atomic number Z but are somewhat lower at higher Z. They are systematically smaller than those of Ziegler et al. at nitrogen energies below 2.5 MeV and larger from 2.5 to 10.0 MeV. For projectile velocities greater than ${\mathit{v}}_{0}$ the stopping in general is found not to be proportional to velocity.