A heaterless hollow cathode provides electron emission current in an electric space propulsion system. A mechanical, thermal, and electromagnetic design of the cathode apparatus is presented, and a method of operation for rapid ignition and stabilization of the cathode is provided. The keeper of the cathode apparatus has a thickness change which reduces the flow of heat away from the cathode's emitter assembly. The method for heating the emitter assembly includes controlling applied voltages so that the current flowing from the emitter assembly to the keeper is maintained at a predetermined fixed value. By this method, damage to the electron emitting surfaces of the emitter assembly by electric arcing and/or by depletion of dopant materials is avoided.

An ion source including a chamber housing defining an ion source chamber and including an extraction plate on a front side thereof, the extraction plate having an extraction aperture formed therein, and a tubular cathode disposed within the ion source chamber and having an opening formed in a front half thereof nearest the extraction aperture, wherein a rear half of the tubular cathode furthest from the extraction aperture is closed.

A system and method for extending the life of a cathode and repeller in an IHC ion source is disclosed. The system monitors the health of the cathode by operating using a known set of parameters and measuring the bias power used to generate the desired extracted beam current or the desired current from the arc voltage power supply. Based on the measured bias power, the system may determine whether the cathode is becoming too thin, and may take a corrective action. This corrective action may be to alert the operator; to operate the IHC ion source using a predetermined set of parameters; or to change the dilution used within the IHC source. By performing these actions, the life of the cathode may be more than doubled.

A Bernas ion source having a shield is disclosed. The shield is disposed between the distal portion of the filament and the first end of the chamber and serves to confine the plasma to the region between the shield and the second end of the chamber. The shield may be electrically connected to the negative leg of the filament so as to be the most negatively biased component in the chamber. In other embodiments, the shield may be electrically floating. In this embodiment, the shield may self-bias. The shield is typically made of a refractory metal. The use of the shield may reduce back heating of the filament by the plasma and reduce the possibility for thermal runaway. This may allow denser plasmas to be generated within the chamber.

Disclosed is a static eliminator having an offset voltage reducing structure capable of improving antistatic performance for a charged body by reducing an ion offset voltage. The present static eliminator comprises a static eliminator body having an air passage through which high-pressure air is supplied, a plurality of discharge structures installed at the lower end of the static eliminator body to supply the high-pressure air passing through the air passage, and generating positive/negative ions by discharging using the applied high voltage, and an offset voltage reduction unit having a plurality of openings formed to allow the positive/negative ions and high-pressure air to pass therethrough, and installed to cover at least some of the plurality of discharge structures.

An assembly present in an ion source for supporting an arc chamber upon a base plate includes a first arc support plate, a first screw, and a second screw. The first screw passes through a smooth through-hole in an arm of the first arc support plate and extends into a bore in the base plate. The second (or adjustable) screw passes through a threaded through-hole in an arm of the first arc support plate and engages an upper surface of the base plate itself, and can be used to change the altitude and angle of the first arc support plate relative to the base plate. This adjustment ability improves the beam quality of the ion source.

An ion gun according to one embodiment of the present invention has an anode, a cathode having a first portion and a second portion that face the anode, and a magnet that creates a spatial magnetic field between the first portion and the second portion. An annular gap including a curved portion is provided between the first portion and the second portion of the cathode. The magnet creates lines of magnetic field having the bottom inside with respect to the sectional center line of the gap between the first portion and the second portion of the curved portion.

An apparatus may include a cyclotron to receive an ion beam as an incident ion beam at an initial energy, and output the ion beam as an accelerated ion beam at an accelerated ion energy. The apparatus may further include an RF source to output an RF power signal to the cyclotron chamber, the RF power source comprising a variable power amplifier, and a movable stripper, translatable to intercept the ion beam within the cyclotron at a continuum of different positions.

A negative ion source includes a plasma chamber, a microwave source, a negative ion converter, a magnetic filter and a beam formation mechanism. The plasma chamber contains gas to be ionized. The microwave source transmits microwaves to the plasma chamber to ionize the gas into atomic species including hyperthermal neutral atoms. The negative ion converter converts the hyperthermal neutral atoms to negative ions. The magnetic filter reduces a temperature of electrons provided between the plasma chamber and the negative ion converter. The beam formation mechanism extracts the negative ions.

A system and method comprising an ion production chamber having an ultra-violet light source disposed towards said chamber, a coated quartz plate between the chamber and the UV source whose coating absorbs incident UV light and ejects electrons into the chamber through the photoelectric effect, a harvest gas disposed to flow through the chamber from an inlet to an outlet, and a jet operable to introduce a sample into the harvest gas flow. In some embodiments the system includes using helium as the harvest gas. Certain embodiments include introducing a sample perpendicular to the harvest gas flow and using multiple sample introduction jets to increase mixing efficiency. In some embodiments the harvest gas and particle sample jet are one and the same. The charge sample may be coupled to a MEMS-based electrometer.