An ion generator includes a high-voltage transformer having a secondary side that is not grounded; a discharge wire-pattern; an induction wire-pattern; a discharge electrode connected to a first terminal via the discharge wire-pattern, the first terminal being disposed on the secondary side of the high-voltage transformer; and an induction electrode connected to a second terminal via the induction wire-pattern, the second terminal being disposed on the secondary side of the high-voltage transformer. The first terminal has a first width. The discharge wire-pattern includes a discharge wide region having a second width greater than the first width. The discharge wide region and the induction wire-pattern at least partly overlap each other in plan view.

The present invention relates to an ion generation composite target for an ion irradiation technology including: a substrate having a through hole formed thereon; and a graphene thin film configured on the substrate, across the through hole, having a thickness in a range between 1 nm to 3 nm, and ionized to release a proton or a carbon ion.

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 an electron density provided between the plasma chamber and the negative ion converter. The beam formation mechanism extract the negative ions.

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 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 having a thermally isolated repeller is disclosed. The repeller comprises a repeller disk and a plurality of spokes originating at the back surface of the repeller disk and terminating in a post. In certain embodiments, the post may be hollow through at least a portion of its length. The use of spokes rather than a central stem may reduce the thermal conduction from the repeller disk to the post. By incorporating a hollow post, the thermal conduction is further reduced. This configuration may increase the temperature of the repeller disk by more than 100 C. In certain embodiments, radiation shields are provided on the back surface of the repeller disk to reduce the amount of radiation emitted from the sides of the repeller disk. This may also help increase the temperature of the repeller. A similar design may be utilized for other electrodes in the ion source.

A system for measuring and controlling the phase of an incoming analog waveform is disclosed. The system comprises an analog to digital converter to convert the incoming analog waveform to a digital representation. The system also includes a clock delay generator, which allows a programmable amount of delay to be introduced into the sample clock for the ADC. The system further comprises a controller to manipulate the delay used by the clock delay generator and store the outputs from the ADC. The controller can then use the digitized representation to determine the frequency of the incoming analog waveform, its phase drift and its phase relative to a master clock. The controller can then modify the output of a RF generator in response to these determinations.

An indirectly heated cathode ion source having an electrically isolated extraction plate is disclosed. By isolating the extraction plate, a different voltage can be applied to the extraction plate than to the body of the arc chamber. By applying a more positive voltage to the extraction plate, more efficient ion source operation with higher plasma density can be achieved. In this mode the plasma potential is increased, and the electrostatic sheath reduces losses of electrons to the chamber walls. By applying a more negative voltage, an ion rich sheath adjacent to the extraction aperture can be created. In this mode, conditioning and cleaning of the extraction plate is achieved via ion bombardment. Further, in certain embodiments, the voltage applied to the extraction plate can be pulsed to allow ion extraction and cleaning to occur simultaneously.

An ion source with an insertable target holder for holding a solid dopant material is disclosed. The insertable target holder includes a hollow interior into which the solid dopant material is disposed. The target holder has a porous surface at a first end, through which vapors from the solid dopant material may enter the arc chamber. The porous surface inhibits the passage of liquid or molten dopant material into the arc chamber. The target holder is also constructed such that it may be refilled with dopant material when the dopant material within the hollow interior has been consumed. The porous surface may be a portion of a perforated crucible, a portion of a perforated retention cap, or a porous insert.

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.