STOPPING CROSS-SECTIONS OF C, AL, AND SI FOR LI-7 IONS

While the advantages of using Li ion in RES have been well known since the 1970s, application of Li ions in ion beam analysis is limited by the uncertainty in stopping power for Li ions and the technical proble ms with Li ion beams. All the systematic models established before 199 3 fail seriously for ail materials studied for energies below about 3. 5-7.0 MeV, which is a good energy range for ion beam analysis, We pres ent recent measurements on the stopping power of C, Al and Si for Li i ons over the energy range from 1 to 7 MeV. The measurements were perfo rmed in transmission geometry with thin films deposited on part of the surface-barrier detector. Comparisons with previous results and diffe rent systematics are discussed.