The Orsay radio-frequency mass spectrometer

An RF mass spectrometer of the L. G. Smith type was built with 2 aims: to provide an experimental test of the CPT invariance (proton-antiproton mass comparison) and to measure the atomic masses of nuclei far from stability produced in the ISOLDE-PS Booster facility. As a priority was given to the first application, the features of the spectrometer are presented in this framework. Then, a discussion is made about the adaptation, currently under way, to the second application.