A focused ion beam (FIB) system is disclosed, comprising an inductively coupled plasma ion source, an insulating plasma chamber containing the plasma, a conducting source biasing electrode in contact with the plasma and biased to a high voltage to control the ion beam energy at a sample, and a plurality of apertures. The plasma within the plasma chamber serves as a virtual source for an ion column comprising one or more lenses which form a focused ion beam on the surface of a sample to be imaged and/or FIB-processed. The plasma is initiated by a plasma igniter mounted near or at the column which induces a high voltage oscillatory pulse on the source biasing electrode. By mounting the plasma igniter near the column, capacitive effects of the cable connecting the source biasing electrode to the biasing power supply are minimized. Ion beam sputtering of the apertures is minimized by proper aperture materials selection.