Electrostatic ion thruster

The Kaufman ion source is a large-scale ion source with high ion current at low operating pressure. It was developed in the late 1950s under the direction of NASA scientist Harold R. Kaufman ion thrusters. It is also used in industrial process.

The ions are formed by electron impact ionization of gas atoms or molecules. The free electrons thermally generated (such as a hot cathode, the electron-optical system without ) or for higher currents to a hollow cathode. The anode is annular. A magnetic multipole field deflects the electrons, so that they travel a longer path in the gas before they are absorbed by the anode. For working pressures are possible in the area of ​​high vacuum. A large-scale control grid gently extracted the ions and shields at the same time the ion source to the high field strength in the subsequent acceleration distance from.