Stopping Powers of Heavy Ions in Hydrogen and Helium Gas
Abstract
Stopping powers for ions in matter are important to nuclear physics experiments and some applied fields, but little experimental data is available for some species. Stopping powers were measured at the Holifield Radioactive Ion Beam Facility (HRIBF) using beams of ^12C, ^19F, and ^24Mg in H2 and He gas. Ions were accelerated to energies in the range of 0.4 - 2.0 MeV/u by the tandem accelerator and passed though a Windowless Gas Target (WGT). The ions were stopped in a silicon detector downstream of the WGT. The distribution of particle energies was measured in the silicon detector when the WGT was evacuated and when it contained about 6 Torr of gas. The difference in energy distributions determined the average energy loss of the ions in the gas. The energy loss of 5.8 MeV alpha particles in the WGT was also measured using a ^244Cm source, and stopping powers for other species were determined relative to the well-known stopping powers for alpha particles. Results are compared to semi-empirical models such as SRIM and MSTAR.
- Publication:
-
APS Division of Nuclear Physics Meeting Abstracts
- Pub Date:
- October 2004
- Bibcode:
- 2004APS..DNP.CK015D