Angular distribution of ion current emerging from an aperture in a vacuum arc

This paper reports on the ion current distribution emerging from a vacuum arc between a Cu cathode and a conical ring anode that was measured by a set of five probes. It was found that the total ion current emerging through the anode was 8.5 percent of the arc current, the measured ion distribution without a magnetic field was a slightly flattened cosinusoidal function, with an axial magnetic field, the ion current distribution became peaked along the z axis, the total ion current extracted through the anode aperture slightly increased with the magnetic field, and an anode with a larger aperture exhibited less magnetic collimation