Capillaritron

The capillaritron, the basic concept of which was published in 1981, consists of a fine metal capillary through which gas flows as an anode and a concentric extraction cathode with an outlet opening.

A flow of gas through the capillary is extracted when high voltage (usually a few kilovolts) is ionised by free electrons and secondary electrons, which are accelerated towards the anode (see also impact ionisation).

[1] Due to recombination and charge exchange processes in the plasma, the beam also partly consists of uncharged atoms.

Here the capillary consists of quartz, an electrically insulating material, into which a metal wire is inserted in order to generate the anode potential.

[3] The advantage lies in the simpler, more flexible and cheaper production of quartz capillaries with a predetermined inner diameter, which, unlike metal capillaries, do not have to be drilled but can be electrochemically etched or manufactured by a glassblower.