an apparatus for the performance of the snms process , having a separate ion source , a sample holder , a system for the production of a radio - frequency plasma and a mass analyzer , in which the ion source and the mass analyzer are disposed side by side on the same side of the chamber provided for the radio - frequency plasma , and in which the sample mounted on the sample holder is situated within the chamber provided for the radio - frequency plasma . this apparatus can be used not only for the performance of the two kinds of snms operation but also secondary ion mass spectroscopy under optimum spatial conditions .