Scattering of ions beyond the single scattering critical angle in HIERDA

Abstract

In Heavy Ion Elastic Recoil Detection Analysis (HIERDA), Rutherford scattering determines the number of scattered and recoiled ions that reach the detector. Because plural scattering is a major contributor to the spectrum and can mask important features and otherwise distort the spectrum it needs to be described correctly. Scattering more than once is a frequent occurrence so many ions scatter beyond the maximum scattering angle possible by a single scattering event. In this work we have chosen projectile/target combinations which enable the exploitation of the scattering critical angle to obtain spectra which are from ions which have all been scattered more than once. Monte Carlo simulation of the ion transport is used to study the plural scattering using a fast FORTRAN version of TRIM. The results of the simulations are compared with experimental measurements on samples of Si, V and Co performed with 20-100 MeV beams of Br, I and Au ions using ToF-E HIERDA facilities at Lucas Heights and Helsinki. © 2003 American Institute of Physics.