The paper presents a modification of the thermal emission Cs⁺ ion source used for SIMS spectroscopy purposes. The source was modified in such a way that both the positive ion beam (in thermal emission mode), and the negative one (in sputter mode) may be emitted by the source.
The mass spectra of both beams are shown and analysed. Also comparison of the secondary ion mass spectra obtained for negative and positive primary ion beams is presented.