Ion gun

The plasma can be made up of an inert or reactive gas (e.g. N+ and O+) or an easily condensable substance (e.g. C+ and B+).

The plasma can be formed from molecules that contain the substance which will form the beam, in which case, these molecules must be fragmented then ionized (e.g. H and CH4 can together be fragmented and ionized to create a beam for depositing diamond-like carbon films).

The ion current density is controlled by the ion source, the energy spread is determined primarily by the extraction grid, and the resolution is determined primarily by the optical column.

A Nanocoulombmeter in combination with a Faraday cup can be used to detect and measure the beams emitted from ion guns.

The term "ion gun" might also refer to an accelerator of any charged particle.