A field emission neutralizer is provided. The field emission neutralizer includes a bottom plate and a field emission cathode unit located on the bottom plate. The field emission cathode unit includes a substrate, a shell located on the substrate, a cathode emitter located inside the shell, a mesh grid insulated from the cathode emitter, and a shielding layer insulated from the mesh grid. The cathode emitter includes a cathode substrate and a graphitized carbon nanotube array. The graphitized carbon nanotube array is in electrical contact with the cathode substrate. The graphitized carbon nanotube array is fixed on a surface of the substrate body, and the carbon nanotubes of the graphitized carbon nanotube array are substantially perpendicular to the cathode substrate.

A liquid metal ion source, in particular an ion thruster for propulsion of a spacecraft, comprises a reservoir for the liquid metal, an emitter penetrating a front wall of the reservoir for drawing liquid metal from the reservoir and emitting ions of the liquid metal, and an extractor supported with respect to the reservoir and facing the emitter for extracting and accelerating the ions from the emitter, wherein the reservoir is provided with advancing means for creating an electromagnetic field within the liquid metal in the reservoir to exert a force on the liquid metal in a direction towards the emitter.

A field emission propulsion system for a spacecraft includes a control unit, a propulsion assembly, and a plurality of extractor electrode voltage sources. The propulsion assembly comprises a plurality of field emission propulsion units having an ion source with a plurality of ion emitters and extractor electrodes associated with the ion emitters and disposed in a field arrangement. The plurality of extractor electrode voltage sources, each associated with the extractor electrodes to control the same, are controlled by the control unit using an individual extractor electrode voltage.

A system can include an emitter structure connected to a reservoir containing a working material, wherein the working material is in electrical communication with a first electrode, an electrode opposing the emitter structure across a gap; and optionally a frame holding the emitter structure and the electrode.

This design processes free radical flows following physical principals that explain their movement conditioned by electromagnetic fields expressed in the convergence of induced field lines, in ways apart from existing designs. It describes specific means to obtain free radicals, process, and exhaust them within uniquely designed processing chambers.

The apparatus includes high frequency resonance transformers that exhaust free radicals into primary processing chambers generating a hot toroidal plasma, confined by an electromagnetic gate at one end of the chamber. The continuous injection of free radicals induce an increase in pressure and temperature that result in velocities greater than thermal electron velocity of the plasma. This velocity variance provides a current that generates a magnetic field component sufficient for conducing a plasma towards an exhaust port at the end of the chamber. As this plasma is exhausted, charge imbalances are realized, provoking additional accelerations of the free radicals.

Electrospray devices and methods of fabricating electrospray devices are described

The disclosed subject matter relates to an ion thruster for thrust vectored propulsion of a spacecraft, comprising a reservoir for a propellant, an emitter having a base and, on one side of the base, at least one outlet for emitting ions of the propellant, wherein the base is connected to the reservoir for providing flow of propellant from the reservoir to said at least one outlet, and an extractor facing said one side of the emitter for extracting and accelerating the ions from the emitter, wherein the extractor is split into sectors about an axis which orthogonally runs through said one side of the emitter, wherein said sectors are electrically insulated from one another.

A polarity-selectable high voltage direct current power supply including a first drive assembly that transforms a first low voltage DC input into a first medium voltage alternating current output; a first HV output assembly that transforms the first LV AC output into a first HV DC output, wherein the first HV output assembly defines a first input stage; a polarity selector coupled between the second output junction of the first drive assembly and the first and second input stages of the first HV output assembly, the polarity selector operable between a first configuration and a second configuration; wherein in the first configuration the first HV DC output has a positive polarity; and wherein in the second configuration the first HV DC output has a negative polarity.

A field emission neutralizer is provided. The field emission neutralizer includes a bottom plate and a field emission cathode unit located on the bottom plate. The field emission cathode unit includes a substrate, a shell located on the substrate, a cathode emitter located inside the shell, a mesh grid insulated from the cathode emitter, and a shielding layer insulated from the mesh grid. The cathode emitter includes a cathode substrate and a graphitized carbon nanotube array. The graphitized carbon nanotube array is in electrical contact with the cathode substrate. The graphitized carbon nanotube array is fixed on a surface of the substrate body, and the carbon nanotubes of the graphitized carbon nanotube array are substantially perpendicular to the cathode substrate.

A polarity-selectable high voltage direct current power supply including a first drive assembly that transforms a first low voltage DC input into a first medium voltage alternating current output; a first HV output assembly that transforms the first LV AC output into a first HV DC output, wherein the first HV output assembly defines a first input stage; a polarity selector coupled between the second output junction of the first drive assembly and the first and second input stages of the first HV output assembly, the polarity selector operable between a first configuration and a second configuration; wherein in the first configuration the first HV DC output has a positive polarity; and wherein in the second configuration the first HV DC output has a negative polarity.