PNNL

Abstract

The stopping powers in silicon of heavy ions, with atomic numbers ranging from 4 to 29, have been determined using a Time-of-Flight Elastic Recoil Detection Analysis (ToF ERDA) set-up. In transmission geometry, the energy loss of heavy elastic recoils in the self-supporting silicon foil of known thickness is measured over a continuous range of recoil energies using Time-of-Flight (ToF) spectrometry. By eliminating the well-known calibration problem of Si detectors for heavy ions, an accuracy of less than 4% is achieved. The stopping powers are parameterized using a sixth order polynomial and compared with the limited experimental data in the literature. In the energy regimes where experimental data exist, the present data exhibit good agreement with most data. Stopping powers predicted by SRIM (The Stopping and Range of Ions in Matter) are in reasonable agreement with much of the experimental data, and SRIM 2003 predictions are in somewhat better agreement than SRIM 2000. There are, however, still some discrepancies between SRIM predictions and the experimental data.