Limits in elastic recoil detection analysis with heavy ions

Severe alterations of the sample by the ion beam limits the detectable concentrations in elastic recoil detection analyses (ERDA). Therefore, sputtering and effusion yields were determined and an enhancement was found in comparison to collisional theory. The sputter yield ranges from 650 carbon atoms per incident 120 MeV Au-197 ion to about 2500 for hydrogen of a hydrogenated polycrystalline c-BN layer for 60 MeV Ni-58 ions, and up to several millions of CHx for organic materials using 60 MeV I-127 ions. In addition plural scattering and secondary reactions limit sensitivity, especially when probing materials which mainly contain light elements. The actual limits in ERD with respect to depth resolution and sensitivity are discussed in terms of these principle effects and those induced by the used detection systems.