ACOLISSA: A powerful set-up for ion beam analysis of surfaces and multilayer structures

The experimental set-up for analysis of the charge of light ions scattered from surface atoms (ACOLISSA) is described in the following paper. ACOLISSA is used for determination of flight times of low-energy ions. It permits time-of-flight low energy ion scattering spectra of all scattered projectiles (TOF-LEIS-AP) as well as charge separated (TOF-LEIS-CS) spectra to be recorded. The evaluation of TOF-LEIS-AP spectra allows subsurface layers of the target to be studied. The analysis of TOF-LEIS-CS spectra together with ions only spectra (TOF-LEIS-IO) is used for investigation of the neutralization behaviour of projectiles at the outermost atomic layer. The performance of the set-up is described and, as an example, spectra are shown for a polycrystalline Cu target and a 7 Å Cu layer deposited on top of an alumina substrate.