A time-of-flight spectrometer with differential pulse sweeping was develope
d for the mass and energy analysis of ions emitted from liquid metal ion so
urces. The system was tested with a gallium liquid metal ion source. The an
gular intensity of the total source current, the mass spectra and the energ
y spread for Ga2+, Ga+ and Ga-2(+) as function of source current have been
measured. A mass and energy resolution of about 700 has been obtained indep
endent of the ion mass.