EP1353352B1 - High-frequency-type electron source, in particular neutralizer - Google Patents

High-frequency-type electron source, in particular neutralizer Download PDF

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Publication number
EP1353352B1
EP1353352B1 EP03007602A EP03007602A EP1353352B1 EP 1353352 B1 EP1353352 B1 EP 1353352B1 EP 03007602 A EP03007602 A EP 03007602A EP 03007602 A EP03007602 A EP 03007602A EP 1353352 B1 EP1353352 B1 EP 1353352B1
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Prior art keywords
frequency
electron source
electrode
electrons
frequency electron
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German (de)
French (fr)
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EP1353352A1 (en
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Karl-Heinz Prof. Dr. Schartner
Horst Prof. Dr. Loeb
Hans Jürgen Leiter
Hans-Peter Harmann
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Airbus DS GmbH
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Astrium GmbH
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J27/00—Ion beam tubes
    • H01J27/02—Ion sources; Ion guns
    • H01J27/16—Ion sources; Ion guns using high-frequency excitation, e.g. microwave excitation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J3/00—Details of electron-optical or ion-optical arrangements or of ion traps common to two or more basic types of discharge tubes or lamps
    • H01J3/02—Electron guns
    • H01J3/025—Electron guns using a discharge in a gas or a vapour as electron source

Definitions

  • the invention relates to a high-frequency electron source, in particular as a neutralizer of an ion source, in particular an ion drive comprising a discharge space with at least one gas inlet for a gas to be ionized and at least one extraction opening for electrons.
  • the neutralizer here consists of a cathode tube, which is closed in the flow direction by a cathode disc with a central bore and an anode disc with also centric bore. Inside the cathode tube is an electron emitter whose porous material is interspersed with alkaline earth metals, including barium. Externally on the cathode tube, a coil-shaped electric heater is mounted, which heats the cathode tube and the electron emitter. This in The barium emitted by the electron emitter emits electrons.
  • the cathode tube with a neutral gas eg. As xenon flows through the electrons collide with the neutral gas atoms, ionizing them, which forms a plasma that emerges through the hole in the anode disc.
  • a disadvantage of this arrangement is that the electron emitter-containing E-mitter material is hygroscopic and also reacts with oxygen at elevated temperatures. This entails severe limitations in storage prior to installation, during satellite installation, and prior to launch into space.
  • Another disadvantage of such complicated and life-limited electron sources is that a pre-heating time of the emitter is preceded by a pre-heating time before switching.
  • Such a high-frequency electron source generates electrons by a plasma which is maintained by the induction caused by an alternating magnetic field. This field is generated by the high-frequency coil through which a high-frequency current flows.
  • the electrons present in the plasma are accelerated by the induction to velocities which, in the case of a collision with a neutral atom in the plasma, can cause the ionization of the latter.
  • velocities which, in the case of a collision with a neutral atom in the plasma, can cause the ionization of the latter.
  • one or more other electrons are released from the neutral atom, resulting in a continuous flow of electrons when working gas flows in.
  • a high-frequency electron source which has a discharge space with a gas inlet for a gas to be ionized and an extraction opening for electrons.
  • the discharge space is at least partially surrounded by a first and a second electrode. Between the two electrons a changing field can be applied.
  • Object of the present invention is to provide a high-frequency electron source, on the one hand has no electron emitter and thus requires no heating time and manages without complicated, costly components, which are to be protected against oxygen and moisture. On the other hand, an electron source is to be provided which has a reduced power requirement.
  • the object is achieved according to the invention by providing means between the electrode and the keeper electrode, whereby a DC voltage can be applied in addition to the electrical high-frequency field.
  • the high-frequency electron source operates with a cold arc discharge by generating the electron-providing plasma with a high-frequency capacitive discharge which is caused by a high-frequency electric field between the electrodes is generated in the discharge space.
  • the electrodes surround the discharge space and form a cavity. They merely have to be suitable for igniting and maintaining the plasma in the discharge space.
  • the ignition of the discharge of the high-frequency electron source can be effected by a pressure surge, which is generated for example by a brief increase in the mass flow through the electron source.
  • a pressure surge which is generated for example by a brief increase in the mass flow through the electron source.
  • the ignition voltage on the so-called Paschen curve is reduced to its minimum and the gas line fails.
  • the accelerated electrons then turn out more electrons from neutral particles and ionize them. This progressive ionization produces a plasma that supplies the required electrons.
  • the advantages of the high-frequency electron source lie in the simple, uncomplicated structure. This eliminates heating including electronics and electron emitter, which also eliminates the restrictions on storage and environmental conditions during installation and operation. For example, a performance test after manufacture is possible without affecting the lifetime of the high frequency electron source under normal environmental conditions.
  • noble gases such as xenon or other suitable gases can be used for operation, which need not be specially cleaned of oxygen and residual moisture for this purpose.
  • the elimination of the preheating and the activation processes also results in a fast availability of electrons, so that when neutralizing an ion drive this can immediately provide its thrust.
  • the high-frequency electron source according to the invention Due to the possibility of operating the high frequency electron source at a relatively low frequency, it is additionally possible on the electronics side, high to achieve electrical efficiencies. In addition, the high-frequency electron source according to the invention has a very low power requirement.
  • the discharge space is surrounded by a plasma chamber.
  • a plasma chamber Preferably, an electrode is designed to form the plasma chamber.
  • an electrode forms the plasma chamber, it is preferably formed as a hollow cathode. In this way, on the one hand, an optimal geometry for the inclusion of the plasma is formed and, in addition, the capacitive coupling of the high-frequency field into the plasma is supported by such a geometry.
  • the orientation of the electrical high-frequency field with respect to the extraction direction of the electrons may be arbitrary, but preferably the electrical high-frequency field is parallel to the extraction direction. In an alternative preferred embodiment, the field may also rest perpendicular to the extraction direction.
  • the discharge frequency can be freely selected within wide limits and can thus be optimally adapted to the requirements.
  • the frequency of the high-frequency electrical field is between 100 KHz and 50 MHz.
  • a high-frequency generator and here particularly advantageously a radio-frequency generator (RF generator) is connected, wherein the connection to the electrodes is accomplished by means of a matching network.
  • the matching network is a toroidal transformer.
  • the field strength of the electric high-frequency field can be optimally adapted to the discharge conditions.
  • the plasma chamber is formed as an electrode, it has been found that it is advantageous to put the keeper electrode on the active output of the RF generator and the electrode to ground potential.
  • the electrode and the keeper electrode are surrounded by a shield electrode.
  • the electrode is at ground potential at the active output of the RF generator and the keeper electrode.
  • the shield electrode can be omitted.
  • the DC voltage can also be applied via the auxiliary electrodes, for which purpose they are grouped around the discharge space.
  • the electrodes are preferably made of a metallic material such as titanium, molybdenum, tungsten, steel, especially stainless steel or aluminum or tantalum.
  • a metallic material such as titanium, molybdenum, tungsten, steel, especially stainless steel or aluminum or tantalum.
  • non-metallic materials are coming especially graphite, carbon composites or conductive ceramics.
  • the Fig. 1 shows the high-frequency electron source 10 with an electrode 12a, which forms a hollow cathode formed as a plasma chamber and the discharge space 11 surrounds.
  • This has a circular cross section and on one side a gas inlet 14 for the operating gas to be ionized, for example xenon.
  • the extraction opening 16 is provided for removing the plasma, including electrons.
  • the plasma chamber designed as electrode 12a is partially surrounded by the keeper electrode 12b.
  • the latter is additionally surrounded by a shield electrode 13.
  • the keeper electrode 12 b and the shield electrode 13 coaxial with the extraction opening 16 on the plasma chamber on an opening to allow removal of the plasma with electrons.
  • the gas inlet 14 is passed through the shield electrode 13.
  • the gas inlet 14 is electrically separated from the electrodes 12a, 13 by means of an insulator 15.
  • the conductive regions in particular the electrode 12a designed as a plasma chamber, must fulfill further conditions in addition to their primary function of ensuring the electrostatic confinement of the electrons. On the one hand, it has to be resistant to the plasma in order to outlast the required operating time with justifiable loss of quality; on the other hand, it must be coupled of the high-frequency electric field and the concomitant maintenance of the plasma does not shield. During operation, ions continuously strike the electrode 12a, resulting in erosion.
  • the temperature of the high frequency electron source may be 300 ° C - 400 ° C. In space technology applications, there are also relatively stringent requirements for a high frequency electron source.
  • the high frequency electron source as a neutralizer for ion engines in aerospace currently 8000 to 15000 hours of operation to guarantee.
  • the high-frequency electron source is operated in a high vacuum, which means that the material - should not have outgassing - a low vapor pressure.
  • the high-frequency electron source should survive the starting loads in transporting the device having such a high-frequency electron source into space.
  • the conductive regions, in particular the electrode 12a are made of titanium, molybdenum, tungsten, steel, aluminum, tantalum, graphite, conductive ceramics or carbon composites.
  • the control of the electrode 12a and the keeper electrode 12b for generating a high frequency electric field with the frequency of eg 1 MHz for the production of a plasma via a radio frequency generator 22, which is connected by means of a toroidal transformer 21 via leads 21a, 21b to the electrodes 12a, 12b is.
  • the supply line 21a and thus the plasma chamber is at ground potential and the supply line 21b and thus also the keeper electrode 12b at the active output of the radio-frequency network. Since no resonance effects are exploited, the discharge frequency is freely selectable within wide limits, so that values between 100 kHz to 50 MHz are possible instead of 1 MHz.
  • a DC voltage is applied to the keeper electrode 12b via the feed line 21b.
  • the leads 21a, 21b are shielded by further insulators 17 with respect to the shield electrode 13 and the keeper electrode 12b, respectively.
  • the operating gas xenon flows via the gas inlet 14 into the discharge space 10.
  • the high-frequency electric field is capacitively coupled into the discharge space 11.
  • the few free electrons that are present in the working gas in the thermal equilibrium accelerated and thus ionize with sufficient energy from the electric high-frequency field, the operating gas.
  • This ionization in turn generates secondary electrons that participate in the process. This creates an electron avalanche, which ultimately leads to the plasma.
  • the plasma in the discharge space 11 is not in thermal equilibrium since almost all of the power of the high frequency electric field is absorbed by the electrons of the plasma and they absorb more power than the ions because of their low mass compared to the ions.
  • the electron temperature is more than a factor of 100 above the ionic and neutral particle temperatures.
  • the xenon gas jet exits to the outside.
  • the gas jet 30 is designed as a supersonic jet 30 (shaded outlined).
  • the gas jet 30 thus transports the high-frequency plasma to the outside.
  • There it can be used as an electron source for the ignition of an engine or as a bridge for coupling the electron into the ion beam.
  • Constant supply of operating gas via the gas inlet constantly replenishes new gas to be ionized, so that the system remains in equilibrium despite removal of part of the plasma.
  • the Fig. 2 shows the high-frequency electron source 10 with electrodes 12a and 12b, between which an alternating electric field is applied.
  • the alternating field is perpendicular to the extraction direction of the electrons, which exit through a Plasmajet 30.
  • the discharge space is terminated electrically insulated from a dielectric discharge chamber 19 with respect to the electrodes 12a and 12b.
  • a DC voltage is applied between the auxiliary electrodes 18a and 18b which are electrically insulated from one another and which is generated by the voltage supply 23.

Abstract

The high frequency electron source has a discharge chamber (11) with at least one gas inlet (14) for a gas to be ionized and at least one extraction opening (16) for electrons. The discharge chamber is at least partly enclosed by at least one electrode (12a) and a keeper electrode (12b) and a high frequency field is applied between the electrodes. The discharge chamber can be enclosed by a plasma chamber.

Description

Die Erfindung betrifft eine Hochfrequenz-Elektronenquelle, insbesondere als Neutralisator einer lonenquelle, insbesondere eines lonenantriebs umfassend einen Entladungsraum mit mindestens einem Gaseinlass für ein zu ionisierendes Gas und mindestens einer Extraktionsöffnung für Elektronen.The invention relates to a high-frequency electron source, in particular as a neutralizer of an ion source, in particular an ion drive comprising a discharge space with at least one gas inlet for a gas to be ionized and at least one extraction opening for electrons.

Überall dort, wo beschleunigte, elektrisch geladene Teilchen benötigt werden-wie dies z. B. auch bei der Oberflächenbehandlung der Fall ist - müssen lonenstrahlen nach dem Beschleunigungsverfahren neutralisiert werden. So werden in der Raumfahrt in steigendem Umfang elektrische Triebwerke benutzt, um Satelliten oder Raumsonden nach ihrer Trennung von der Trägerrakete anzutreiben. Speziell für das Stationskeeping von geostationären Kommunikationssatelliten werden elektrische Triebwerke bereits heute eingesetzt. Hierzu werden vor allem lonentriebwerke und SPT-Plasmatriebwerke genutzt. Beide Typen erzeugen ihren Schub, indem beschleunigte lonen ausgestoßen werden. Um eine Aufladung des Satelliten jedoch zu vermeiden, muss dieser lonenstrahl neutralisiert werden. Die hierzu benötigten Elektronen werden aus einer Elektronenquelle bereitgestellt und mittels Plasmakopplung in den lonenstrahl eingebracht.Wherever accelerated, electrically charged particles are needed - as z. B. also in the surface treatment is the case - ion beams must be neutralized after the acceleration process. In aerospace, electric engines are increasingly used to power satellites or spacecraft after their separation from the launcher. Electric engines are already being used today for the stationkeeping of geostationary communications satellites. For this purpose, mainly ion engines and SPT plasma engines are used. Both types generate their thrust by ejecting accelerated ions. However, to avoid charging the satellite, this ion beam must be neutralized. The electrons required for this purpose are provided from an electron source and introduced into the ion beam by means of plasma coupling.

Bisher werden in der Raumfahrt zur Neutralisierung dieser elektrischen Triebwerke (lonentriebwerke und SPT-Plasmatriebwerke) Hohlkathoden-Plasmabrücken-Neutralisatoren mit Elektronenemitter verwendet. Der Neutralisator besteht hierbei aus einem Kathodenrohr, das in Strömungsrichtung durch eine Kathodenscheibe mit einer zentrischen Bohrung abgeschlossen ist und einer Anodenscheibe mit ebenfalls zentrischer Bohrung. Im Inneren des Kathodenrohres befindet sich ein Elektronenemitter, dessen poröses Material mit Erdalkalimetallen, u. a. Barium, durchsetzt ist. Außen am Kathodenrohr ist eine spulenförmige elektrische Heizung angebracht, die das Kathodenrohr und den Elektronenemitter erwärmt. Das in dem Elektronenemitter enthaltene Barium emittiert dabei Elektronen. Durch eine zwischen Anodenscheibe und Kathodenscheibe angelegte Spannung werden diese beschleunigt, Wird das Kathodenrohr mit einem Neutralgas, z. B. Xenon durchströmt, stoßen die Elektronen mit den neutralen Gasatomen zusammen, ionisieren diese, womit sich ein Plasma bildet, das durch die Bohrung in der Anodenscheibe austritt.So far in space travel to neutralize these electric thrusters (ion thrusters and SPT plasma thrusters), hollow-cathode plasma-bridge neutralizers with electron emitters have been used. The neutralizer here consists of a cathode tube, which is closed in the flow direction by a cathode disc with a central bore and an anode disc with also centric bore. Inside the cathode tube is an electron emitter whose porous material is interspersed with alkaline earth metals, including barium. Externally on the cathode tube, a coil-shaped electric heater is mounted, which heats the cathode tube and the electron emitter. This in The barium emitted by the electron emitter emits electrons. By an applied voltage between the anode plate and the cathode plate these are accelerated, the cathode tube with a neutral gas, eg. As xenon flows through the electrons collide with the neutral gas atoms, ionizing them, which forms a plasma that emerges through the hole in the anode disc.

Ein Nachteil dieser Anordnung ist, dass das im Elektronenemitter enthaltende E-mittermaterial hygroskopisch ist und zudem bei erhöhten Temperaturen mit Sauerstoff reagiert. Dies zieht starke Einschränkungen in der Lagerung vor dem Einbau, während der Montage am Satelliten und der Inbetriebnahme vor dem Start in den Weltraum nach sich. Ein weiterer Nachteil derartiger komplizierter und lebensdauerbegrenzter Elektronenquellen liegt darin, dass vor dem Einschalten eine mehrminütige Vorheizzeit des Emitters vorgeschaltet ist.A disadvantage of this arrangement is that the electron emitter-containing E-mitter material is hygroscopic and also reacts with oxygen at elevated temperatures. This entails severe limitations in storage prior to installation, during satellite installation, and prior to launch into space. Another disadvantage of such complicated and life-limited electron sources is that a pre-heating time of the emitter is preceded by a pre-heating time before switching.

Weiterhin ist aus US 5,198,718 ein Neutralisator für eine lonenquelle bekannt, die aus einer Plasmakammer mit aus dielektrischem Material bestehenden Wänden besteht und von einer Hochfrequenzspule umgeben ist.Furthermore, it is off US 5,198,718 a neutralizer for an ion source consisting of a plasma chamber with walls made of dielectric material and surrounded by a radio-frequency coil.

Eine derartige Hochfrequenzelektronenquelle erzeugt Elektronen durch ein Plasma, das durch die Induktion hervorgerufen durch ein magnetisches Wechselfeld aufrecht erhalten wird. Dieses Feld wird dabei durch die Hochfrequenzspule erzeugt, durch die ein hochfrequenter Strom fließt. Die im Plasma vorhandenen Elektronen werden durch die Induktion auf Geschwindigkeiten bescheunigt, die im Falle des Stoßes mit einem Neutralatom im Plasma die Ionisation des letzteren bewirken können. Bei der Ionisation werden ein oder mehrere weitere Elektronen vom Neutralatom freigeschlagen, woraus sich bei nachströmendem Arbeitsgas ein kontinuierlicher Fluss an Elektronen ergibt.Such a high-frequency electron source generates electrons by a plasma which is maintained by the induction caused by an alternating magnetic field. This field is generated by the high-frequency coil through which a high-frequency current flows. The electrons present in the plasma are accelerated by the induction to velocities which, in the case of a collision with a neutral atom in the plasma, can cause the ionization of the latter. During ionization, one or more other electrons are released from the neutral atom, resulting in a continuous flow of electrons when working gas flows in.

Nachteilig wirkt sich bei einer derartigen Elektronenquelle aus, dass ein großer Teil der zur Aufrechterhaltung des Plasmas in der Plasmakammer benötigten Leistung dadurch verloren geht, dass hochenergetische Elektronen aus dem Plasma auf die Kammerwand treffen und dabei wieder an Atome gebunden werden. Durch diesen Prozess gehen zum einen diese Elektronen verloren, zum anderen wird dadurch ein Großteil der Energie abgegeben, die die Elektronen durch das Wechselfeld gewonnen haben. Zudem wird durch die Hochfrequenzspule in der Plasmakammerwand ein Ringstrom (Wirbelstrom) induziert, wodurch Energie verloren geht, welche nicht mehr an das Plasma abgegeben werden kann.The disadvantage of such an electron source is that a large part of the power required to maintain the plasma in the plasma chamber is lost in that high-energy electrons from the plasma strike the chamber wall and are thereby bound to atoms again. On the one hand, these electrons are lost as a result of this process, and on the other hand, a large part of the energy that the electrons have gained through the alternating field is released. In addition, a ring current (eddy current) is induced by the high frequency coil in the plasma chamber wall, whereby energy is lost, which can not be released to the plasma.

Aus der US 5,003,226 ist ferner eine Hochfrequenz-Elektronenquelle bekannt, die einen Entladungsraum mit einem Gaseinlass für ein zu ionisierendes Gas und eine Extraktionsöffnung für Elektronen aufweist. Der Entladungsraum ist von einer ersten und zweiten Elektrode zumindest teilweise umgeben. Zwischen den beiden Elektronen ist ein wechselndes Feld anlegbar.From the US 5,003,226 Further, a high-frequency electron source is known, which has a discharge space with a gas inlet for a gas to be ionized and an extraction opening for electrons. The discharge space is at least partially surrounded by a first and a second electrode. Between the two electrons a changing field can be applied.

Aufgabe der vorliegenden Erfindung ist es, eine Hochfrequenz-Elektronenquelle bereitzustellen, die einerseits keinen Elektronenemitter aufweist und somit keiner Aufheizzeit bedarf sowie ohne komplizierte, kostenintensive Bauteile auskommt, welche gegen Sauerstoff und Feuchtigkeit zu schützen sind. Andererseits soll eine Elektronenquelle bereitgestellt werden, die einen verringerten Leistungsbedarf aufweist.Object of the present invention is to provide a high-frequency electron source, on the one hand has no electron emitter and thus requires no heating time and manages without complicated, costly components, which are to be protected against oxygen and moisture. On the other hand, an electron source is to be provided which has a reduced power requirement.

Die Lösung der Aufgabe wird erfindungsgemäß dadurch erzielt, dass zwischen der Elektrode und der Keeper-Elektrode mittel vorgeshenen sind, womit zusätzlich zum elektrischen Hochfrequenzfeld eine Gleichspannung beaufschlagbar ist.The object is achieved according to the invention by providing means between the electrode and the keeper electrode, whereby a DC voltage can be applied in addition to the electrical high-frequency field.

Erfindungsgemäß arbeitet die Hochfrequenz-Elektronenquelle mit einer kalten Bogenentladung, indem das Elektronen liefernde Plasma mit einer kapazitiven Hochfrequenzentladung erzeugt wird, die durch ein elektrisches Hochfrequenzfeld zwischen den Elektroden im Entladungsraum erzeugt wird. Für die Erfindung ist es nicht notwendig, dass die Elektroden den Entladungsraum umgeben und einen Hohlraum bilden. Sie müssen lediglich dazu geeignet sein, das Plasma im Entladungsraum zu zünden und aufrechtzuerhalten.According to the invention, the high-frequency electron source operates with a cold arc discharge by generating the electron-providing plasma with a high-frequency capacitive discharge which is caused by a high-frequency electric field between the electrodes is generated in the discharge space. For the invention, it is not necessary that the electrodes surround the discharge space and form a cavity. They merely have to be suitable for igniting and maintaining the plasma in the discharge space.

Das Zünden der Entladung der Hochfrequenz-Elektronenquelle kann durch einen Druckstoß erfolgen, der beispielsweise durch eine kurzzeitige Erhöhung des Massenflusses durch die Elektronenquelle erzeugt wird. Damit wird die Zündspannung auf der sogenannten Paschen-Kurve auf ihr Minimum reduziert und die Gasstrecke schlägt durch. Die beschleunigten Elektronen schlagen dann wiederum weitere Elektronen aus Neutralteilchen heraus und ionisieren diese. Durch diese fortschreitende Ionisation entsteht ein Plasma, welches die benötigten Elektronen liefert.The ignition of the discharge of the high-frequency electron source can be effected by a pressure surge, which is generated for example by a brief increase in the mass flow through the electron source. Thus, the ignition voltage on the so-called Paschen curve is reduced to its minimum and the gas line fails. The accelerated electrons then turn out more electrons from neutral particles and ionize them. This progressive ionization produces a plasma that supplies the required electrons.

Die Vorteile der Hochfrequenz-Elektronenquelle liegen im einfachen, unkomplizierten Aufbau. So entfallen Heizung samt Elektronik und Elektronenemitter, womit auch die Einschränkungen zu Lagerung und bezüglich der Umgebungsbedingungen während Montage und Betrieb entfallen. Beispielsweise ist ein Test der Funktionstauglichkeit nach der Herstellung ohne Beeinträchtigung der Lebensdauer der Hochfrequenz-Elektronenquelle unter normalen Umweltbedingungen möglich. Außerdem können zum Betrieb Edelgase wie Xenon oder andere geeignete Gase verwendet werden, die hierfür nicht speziell von Sauerstoff und Restfeuchtigkeit gereinigt werden müssen. Durch den Wegfall der Vorheizzeit und der Aktivierungsprozesse ergibt sich außerdem eine schnelle Verfügbarkeit der Elektronen, so dass bei einer Neutralisierung eines Ionenantriebs dieser sofort seinen Schub zur Verfügung stellen kann.The advantages of the high-frequency electron source lie in the simple, uncomplicated structure. This eliminates heating including electronics and electron emitter, which also eliminates the restrictions on storage and environmental conditions during installation and operation. For example, a performance test after manufacture is possible without affecting the lifetime of the high frequency electron source under normal environmental conditions. In addition, noble gases such as xenon or other suitable gases can be used for operation, which need not be specially cleaned of oxygen and residual moisture for this purpose. The elimination of the preheating and the activation processes also results in a fast availability of electrons, so that when neutralizing an ion drive this can immediately provide its thrust.

Durch die Möglichkeit, die Hochfrequenz-Elektronenquelle mit einer relativ geringen Frequenz zu betreiben, ist es auf der Elektronikseite zusätzlich möglich, hohe elektrische Wirkungsgrade zu erzielen. Hinzu kommt, dass die erfindungsgemäße Hochfrequenz-Elektronenquelle einen sehr geringen Leistungsbedarf aufweist.Due to the possibility of operating the high frequency electron source at a relatively low frequency, it is additionally possible on the electronics side, high to achieve electrical efficiencies. In addition, the high-frequency electron source according to the invention has a very low power requirement.

Bevorzugt ist der Entladungsraum von einer Plasmakammer umgeben. Hierdurch wird ein möglicher Gasverlust minimiert. Insbesondere ist eine Elektrode so gestaltet, dass sie die Plasmakammer bildet.Preferably, the discharge space is surrounded by a plasma chamber. This minimizes possible gas loss. In particular, an electrode is designed to form the plasma chamber.

Bildet eine Elektrode die Plasmakammer, so wird diese bevorzugt als Hohlkathode ausgebildet. Hierdurch ist zum einen eine optimale Geometrie für den Einschluss des Plasmas gebildet und außerdem wird die kapazitive Einkopplung des Hochfrequenzfeldes in das Plasma durch eine derartige Geometrie unterstützt.If an electrode forms the plasma chamber, it is preferably formed as a hollow cathode. In this way, on the one hand, an optimal geometry for the inclusion of the plasma is formed and, in addition, the capacitive coupling of the high-frequency field into the plasma is supported by such a geometry.

Die Ausrichtung des elektrischen Hochfrequenzfeldes bezogen auf die Extraktionsrichtung der Elektronen kann beliebig sein, bevorzugt liegt das elektrische Hochfrequenzfeld aber parallel zur Extraktionsrichtung an. In einer alternativen vorzugsweisen Ausführungsform kann das Feld auch senkrecht zur Extraktionsrichtung anliegen.The orientation of the electrical high-frequency field with respect to the extraction direction of the electrons may be arbitrary, but preferably the electrical high-frequency field is parallel to the extraction direction. In an alternative preferred embodiment, the field may also rest perpendicular to the extraction direction.

Da keine Resonanzeffekte ausgenutzt werden müssen, ist die Entladungsfrequenz in weiten Grenzen frei wählbar und kann somit an die Erfordernisse optimal angepasst werden. Vorzugsweise liegt die Frequenz des elektrischen Hochfreqenzfeldes jedoch zwischen 100 KHz und 50 MHz.Since no resonance effects have to be exploited, the discharge frequency can be freely selected within wide limits and can thus be optimally adapted to the requirements. Preferably, however, the frequency of the high-frequency electrical field is between 100 KHz and 50 MHz.

Zur Erzeugung des elektrischen Hochfrequenzfeldes ist vorteilhafterweise zwischen die Elektrode und die Keeper-Elektrode ein Hochfrequenzgenerator (HF-Generator) und hier besonders vorteilhaft ein Radiofrequenzgenerator (RF-Generator) geschaltet, wobei der Anschluss an die Elektroden mittels eines Anpassungsnetzwerkes bewerkstelligt wird. Dabei ist es insbesondere vorgesehen, dass es sich bei dem Anpassungsnetzwerk um einen Ringkerntransformator handelt. Bei einer derartigen Ausgestaltung kann die Feldstärke des elektrischen Hochfrequenzfeldes den Entladebedingungen optimal angepasst werden.To generate the electrical high-frequency field is advantageously between the electrode and the keeper electrode, a high-frequency generator (RF generator) and here particularly advantageously a radio-frequency generator (RF generator) is connected, wherein the connection to the electrodes is accomplished by means of a matching network. In particular, it is provided that the matching network is a toroidal transformer. In such an embodiment, the field strength of the electric high-frequency field can be optimally adapted to the discharge conditions.

Bei einer Anordnung in der Form, dass die Plasmakammer als Elektrode ausgebildet ist, hat es sich herausgestellt, dass es von Vorteil ist, die Keeper-Elektrode auf den aktiven Ausgang des HF-Generators und die Elektrode auf Massepotential zu legen.In an arrangement in the form that the plasma chamber is formed as an electrode, it has been found that it is advantageous to put the keeper electrode on the active output of the RF generator and the electrode to ground potential.

Aus Gründen der elektrischen Abschirmung gegenüber der Umgebung ist es hierbei von Vorteil, dass die Elektrode und die Keeper-Elektrode von einer Schirmelektrode umgeben werden.For reasons of electrical shielding from the environment, it is advantageous in this case that the electrode and the keeper electrode are surrounded by a shield electrode.

In einer anderen bevorzugten Ausführungsform liegt die Elektrode am aktiven Ausgang des HF-Generators und die Keeper-Elektrode auf Massepotential. Hier kann die Schirmelektrode entfallen.In another preferred embodiment, the electrode is at ground potential at the active output of the RF generator and the keeper electrode. Here, the shield electrode can be omitted.

In einer alternativen Ausführungsform kann die Gleichspannung aber auch über die Hilfselektroden angelegt werden, wofür diese um den Entladungsraum herum gruppiert werden.In an alternative embodiment, however, the DC voltage can also be applied via the auxiliary electrodes, for which purpose they are grouped around the discharge space.

Für die Elektroden kann grundsätzlich jedes geeignete Material gewählt werden, das den Anforderungen an eine solche Elektronenquelle und ihrem speziellen Einsatzgebiet gerecht wird. Bevorzugt sind die Elektroden jedoch aus einem metallischen Werkstoff, wie Titan, Molybdän, Wolfram, Stahl, speziell rostfreier Stahl oder auch aus Aluminium oder Tantal. Als nichtmetallische Werkstoffe sind kommen besonders Graphit, Kohlenstoffverbundwerkstoffe oder leitfähige Keramiken in Betracht.In principle, any suitable material can be selected for the electrodes that meets the requirements of such an electron source and its specific field of application. However, the electrodes are preferably made of a metallic material such as titanium, molybdenum, tungsten, steel, especially stainless steel or aluminum or tantalum. As non-metallic materials are coming especially graphite, carbon composites or conductive ceramics.

Die Erfindung wird im folgenden anhand zweier in zwei Zeichnungen dargestellten Ausführungsbeispiele näher beschrieben, aus denen sich weitere Einzelheiten, Merkmale und Vorzüge ergeben.The invention will be described in more detail below with reference to two exemplary embodiments illustrated in two drawings, from which further details, features and advantages result.

Es zeigen

Fig. 1
einen schematischen Aufbau der erfindungsgemäßen HochfrequenzElektronenquelle in einer Ausgestaltung mit einer als Hohlkathode ausgebildeten Plasmakammer und Schirmelektrode.
Fig. 2
einen schematischen Aufbau in einer Ausgestaltung mit einer gegenüber den Elektroden elektrisch isolierten Plasmakammer.
Show it
Fig. 1
a schematic structure of the high-frequency electron source according to the invention in an embodiment with a designed as a hollow cathode plasma chamber and shield electrode.
Fig. 2
a schematic structure in an embodiment with a relation to the electrodes electrically isolated plasma chamber.

Die Fig. 1 zeigt die Hochfrequenz-Elektronenquelle 10 mit einer Elektrode 12a, die eine als Hohlkathode ausgebildeten Plasmakammer bildet und den Entladungsraum 11 umgibt. Diese hat einen kreisförmigen Querschnitt und auf der einen Seite einen Gaseinlass 14 für das zu ionisierende Betriebsgas, beispielsweise Xenon. Koaxial am anderen Ende der Plasmakammer angeordnet ist die Extraktionsöffnung 16 zur Entnahme des Plasmas samt Elektronen vorgesehen. Die als Plasmakammer ausgebildete Elektrode 12a ist von der Keeper-Elektrode 12b teilweise umgeben. Letztere ist zusätzlich von einer Schirmelektrode 13 umgeben. Dabei weisen auch die Keeper-Elektrode 12 b und die Schirmelektrode 13 koaxial mit der Extraktionsöffnung 16 an der Plasmakammer eine Öffnung auf, um eine Entnahme des Plasmas mit Elektronen zu ermöglichen. Aus Gründen der vollständigen Umschließung der Plasmakammer 12a mit der Schirmelektrode ist der Gaseinlass 14 durch die Schirmelektrode 13 geführt . Zur elektrischen Entkopplung ist der Gaseinlass 14 mittels eines Isolators 15 elektrisch von den Elektroden 12a, 13 getrennt.The Fig. 1 shows the high-frequency electron source 10 with an electrode 12a, which forms a hollow cathode formed as a plasma chamber and the discharge space 11 surrounds. This has a circular cross section and on one side a gas inlet 14 for the operating gas to be ionized, for example xenon. Coaxially arranged at the other end of the plasma chamber, the extraction opening 16 is provided for removing the plasma, including electrons. The plasma chamber designed as electrode 12a is partially surrounded by the keeper electrode 12b. The latter is additionally surrounded by a shield electrode 13. In this case, the keeper electrode 12 b and the shield electrode 13 coaxial with the extraction opening 16 on the plasma chamber on an opening to allow removal of the plasma with electrons. For reasons of complete enclosure of the plasma chamber 12a with the shield electrode, the gas inlet 14 is passed through the shield electrode 13. For electrical decoupling, the gas inlet 14 is electrically separated from the electrodes 12a, 13 by means of an insulator 15.

Die leitfähigen Bereiche, insbesondere die als Plasmakammer ausgebildete Elektrode 12a muss neben ihrer primären Funktion zur Gewährleistung des elektrostatischen Einschlusses der Elektronen weitere Bedingungen erfüllen. Zum einen muss sie gegenüber dem Plasma resistent sein, um die geforderte Betriebszeit mit vertretbarem Qualitätsverlust zu überdauern, zum anderen darf sie die Einkopplung des elektrischen Hochfrequenzfeldes und die damit einhergehende Aufrechtherhaltung des Plasmas nicht abschirmen. Während des Betriebs treffen laufend lonen auf der Elektrode 12a auf, was zu einer Erosion führt. Außerdem kann die Temperatur der Hochfrequenz-Elektronenquelle bei 300° - 400° C liegen.
Bei der Anwendung in der Raumfahrttechnik bestehen zudem relativ strenge Anforderungen an eine Hochfrequenz-Elektronenquelle . So sind für die Anwendung der Hochfrequenz-Elektronenquelle als Neutralisator für lonentriebwerke in der Raumfahrt derzeit 8000 bis 15000 Stunden Betriebszeit zu garantieren. Hinzu kommt, dass die Hochfrequenz-Elektronenquelle im Hochvakuum betrieben wird, womit der Werkstoff - um nicht auszugasen - einen niedrigen Dampfdruck aufweisen sollte. Letztlich sollte die Hochfrequenz-Elektronenquelle die Startlasten beim Transport der Einrichtung, die eine solche Hochfrequenz-Elektronenquelle aufweist, in den Weltraum überstehen. Hierfür gibt es insbesondere einige metallische und nichtmetallische Werkstoffe, die diesen Anforderungen gerecht werden, so dass die leitfähigen Bereiche, insbesondere die Elektrode 12a, aus Titan, Molybdän, Wolfram, Stahl, Aluminium, Tantal, Graphit, leitfähiger Keramik oder Kohlenstoffverbundwerkstoffen hergestellt ist.The conductive regions, in particular the electrode 12a designed as a plasma chamber, must fulfill further conditions in addition to their primary function of ensuring the electrostatic confinement of the electrons. On the one hand, it has to be resistant to the plasma in order to outlast the required operating time with justifiable loss of quality; on the other hand, it must be coupled of the high-frequency electric field and the concomitant maintenance of the plasma does not shield. During operation, ions continuously strike the electrode 12a, resulting in erosion. In addition, the temperature of the high frequency electron source may be 300 ° C - 400 ° C.
In space technology applications, there are also relatively stringent requirements for a high frequency electron source. Thus, for the application of the high frequency electron source as a neutralizer for ion engines in aerospace currently 8000 to 15000 hours of operation to guarantee. In addition, the high-frequency electron source is operated in a high vacuum, which means that the material - should not have outgassing - a low vapor pressure. Ultimately, the high-frequency electron source should survive the starting loads in transporting the device having such a high-frequency electron source into space. In particular, there are some metallic and non-metallic materials which meet these requirements, such that the conductive regions, in particular the electrode 12a, are made of titanium, molybdenum, tungsten, steel, aluminum, tantalum, graphite, conductive ceramics or carbon composites.

Die Ansteuerung der Elektrode 12a und der Keeper-Elektrode 12b zur Erzeugung eines elektrischen Hochfrequenzfeldes mit der Frequenz von z.B. 1 MHz zur Herstellung eines Plasmas erfolgt über einen Radiofrequenzgenerator 22, der mittels eines Ringkerntransformators 21 über Zuleitungen 21a, 21b an die Elektroden 12a, 12b angeschlossen ist. Dabei liegt die Zuleitung 21a und somit die Plasmakammer auf Massepotential und die Zuleitung 21b und damit auch die Keeper-Elektrode 12b am aktiven Ausgang des Radiofrequenz-Netzes an. Da keine Resonanzeffekte ausgenutzt werden, ist die Entladungsfrequenz in weiten Grenzen frei wählbar, so dass anstelle von 1 MHz auch Werte zwischen 100 KHz bis 50 MHz möglich sind. Zusätzlich zum elektrischen Hochfrequenzfeld liegt über die Zuleitung 21b eine Gleichspannung an der Keeper-Elektrode 12b an. Hierdurch können der Elektronenaustritt aus dem Entladungsplasma erleichtert und der Wirkungsgrad der Elektronenquelle verbessert werden. Um die elektrische Isolierung zwischen den verschiedenen Elektroden zu gewährleisten, sind die Zuleitungen 21a, 21b über weitere Isolatoren 17 gegenüber der Schirmelektrode 13 bzw. der Keeper-Elektrode 12b abgeschirmt.The control of the electrode 12a and the keeper electrode 12b for generating a high frequency electric field with the frequency of eg 1 MHz for the production of a plasma via a radio frequency generator 22, which is connected by means of a toroidal transformer 21 via leads 21a, 21b to the electrodes 12a, 12b is. In this case, the supply line 21a and thus the plasma chamber is at ground potential and the supply line 21b and thus also the keeper electrode 12b at the active output of the radio-frequency network. Since no resonance effects are exploited, the discharge frequency is freely selectable within wide limits, so that values between 100 kHz to 50 MHz are possible instead of 1 MHz. In addition to the electrical high-frequency field, a DC voltage is applied to the keeper electrode 12b via the feed line 21b. As a result, the electron leakage from the discharge plasma can be facilitated and the efficiency the electron source can be improved. In order to ensure the electrical insulation between the various electrodes, the leads 21a, 21b are shielded by further insulators 17 with respect to the shield electrode 13 and the keeper electrode 12b, respectively.

Zum Zünden des Plasmas strömt das Betriebsgas Xenon über den Gaseinlass 14 in den Entladungsraum 10. Zwischen der als Plasmakammer ausgebildeten Elektrode 12a und der Keeper-Elektrode 12b liegt das elektrische Hochfrequenzfeld an. Dieses wird kapazitiv in den Entladungsraum 11 eingekoppelt. Hierdurch werden die wenigen freien Elektronen, die im Arbeitsgas im thermischen Gleichgewicht vorhanden sind, beschleunigt und stoßionisieren somit bei ausreichender Energie aus dem elektrischen Hochfrequenzfeld das Betriebsgas. Durch diese Ionisation werden wiederum Sekundärelektronen erzeugt, die am Prozess teilnehmen. Es entsteht somit eine Elektronenlawine, die letztendlich zum Plasma führt. Das Plasma im Entladungsraum 11 befindet sich jedoch nicht im thermischen Gleichgewicht, da fast die gesamte Leistung des elektrischen Hochfrequenzfeldes von den Elektronen des Plasmas absorbiert wird und diese aufgrund ihrer geringen Masse im Vergleich zu den lonen mehr Leistung aufnehmen als die lonen. Dies hat zur Folge, dass die Elektronentemperatur um mehr als einen Faktor 100 über der Ionen- und Neutralteilchentemperatur liegt.To ignite the plasma, the operating gas xenon flows via the gas inlet 14 into the discharge space 10. Between the plasma chamber designed as electrode 12a and the keeper electrode 12b is the high-frequency electric field. This is capacitively coupled into the discharge space 11. As a result, the few free electrons that are present in the working gas in the thermal equilibrium, accelerated and thus ionize with sufficient energy from the electric high-frequency field, the operating gas. This ionization in turn generates secondary electrons that participate in the process. This creates an electron avalanche, which ultimately leads to the plasma. However, the plasma in the discharge space 11 is not in thermal equilibrium since almost all of the power of the high frequency electric field is absorbed by the electrons of the plasma and they absorb more power than the ions because of their low mass compared to the ions. As a result, the electron temperature is more than a factor of 100 above the ionic and neutral particle temperatures.

Durch die Extraktionsöffnung 16 tritt der Xenon-Gasstrahl nach außen. Im vorliegenden Beispiel ist er als Überschall-Jet 30 ausgebildet (schraffiert skizziert). Der Gasstrahl 30 transportiert somit das Hochfrequenz-Plasma nach außen. Dort kann es als Elektronenquelle für die Zündung eines Triebwerkes oder auch als Brücke zur Einkopplung der Elektronen in den lonenstrahl verwendet werden. Durch ständige Nachlieferung von Betriebsgas über den Gaseinlass wird ständig neues zu ionisierendes Gas nachgeliefert, so dass das System trotz Entnahme eines Teils des Plasmas im Gleichgewicht bleibt.Through the extraction opening 16, the xenon gas jet exits to the outside. In the present example it is designed as a supersonic jet 30 (shaded outlined). The gas jet 30 thus transports the high-frequency plasma to the outside. There it can be used as an electron source for the ignition of an engine or as a bridge for coupling the electron into the ion beam. Constant supply of operating gas via the gas inlet constantly replenishes new gas to be ionized, so that the system remains in equilibrium despite removal of part of the plasma.

Die Fig. 2 zeigt die Hochfrequenz-Elektronenquelle 10 mit Elektroden 12a und 12b, zwischen denen ein elektrisches Wechselfeld anliegt. Das Wechselfeld liegt dabei senkrecht zur Extraktionsrichtung der Elektronen, die durch einen Plasmajet 30 austreten. Der Entladungsraum ist von einer dielektrischen Entladungskammer 19 gegenüber den Elektroden 12a und 12b elektrisch isoliert abgeschlossen. Zur Unterstützung der Extraktion liegt zwischen den voneinander elektrisch isolierten Hilfselektroden 18a und 18b eine Gleichspannung an, die durch die Spannungsversorgung 23 erzeugt wird.The Fig. 2 shows the high-frequency electron source 10 with electrodes 12a and 12b, between which an alternating electric field is applied. The alternating field is perpendicular to the extraction direction of the electrons, which exit through a Plasmajet 30. The discharge space is terminated electrically insulated from a dielectric discharge chamber 19 with respect to the electrodes 12a and 12b. To assist the extraction, a DC voltage is applied between the auxiliary electrodes 18a and 18b which are electrically insulated from one another and which is generated by the voltage supply 23.

Claims (13)

  1. High-frequency electron source (10), in particular as a neutralizer of an ion source, in particular of an ion drive, comprising a discharge chamber (11) having at least a gas inlet (14) for a gas to be ionized and at least an extraction aperture (16) for electrons, the discharge chamber (11) being at least partially surrounded by at least an electrode (12a) and a keeper electrode (12b), and it being possible to apply a high-frequency electric field between the electrodes, characterized in that there are provided between the electrode (12a) and the keeper electrode (12b) means with the aid of which a direct voltage can be applied in addition to the high-frequency electric field.
  2. High-frequency electron source (10) according to Claim 1, characterized in that the discharge chamber (11) is surrounded by a plasma chamber.
  3. High-frequency electron source (10) according to Claim 2, characterized in that the plasma chamber is designed as an electrode (12a, 12b).
  4. High-frequency electron source (10) according to Claim 3, characterized in that the electrode (12a) is designed as a hollow cathode.
  5. High-frequency electron source (10) according to one or more of the preceding claims, characterized in that the high-frequency electric field is applied parallel to the extraction direction of the electrons.
  6. High-frequency electron source (10) according to one or more of the preceding claims, characterized in that the high-frequency electric field is applied perpendicular to the extraction direction of the electrons.
  7. High-frequency electron source (10) according to one or more of the preceding claims, characterized in that the high-frequency electric field has a frequency of 100 KHz to 50 MHz.
  8. High-frequency electron source (10) according to one or more of the preceding claims, characterized in that a high-frequency generator, in particular a radiofrequency generator (22) with matching network, in particular a torroidal-core transformer (21), generates the high-frequency electric field.
  9. High-frequency electron source (10) according to one or more of the preceding Claims 3 to 8, characterized in that the keeper electrode (12b) is present at the active output of the high-frequency generator (22), and the electrode (12a) is at earth potential.
  10. High-frequency electron source (10) according to Claim 9, characterized in that the keeper electrode (12b) is surrounded by a screen electrode (13).
  11. High-frequency electron source (10) according to one or more of Claims 3 to 8, characterized in that the electrode (12a) is present at the active output of the high-frequency generator (22), and the keeper electrode (12b) is at earth potential.
  12. High-frequency electron source (10) according to one or more of the preceding claims, characterized in that fitted at the discharge chamber (11) are auxiliary electrodes (18a, 18b) between which a direct voltage is present.
  13. High-frequency electron source (10) according to one or more of the preceding claims, characterized in that the electrode (12a) and/or keeper electrode (12b) and/or the auxiliary electrodes (18a, 18b) consist of a metal material from the group of titanium, molybdenum, tungsten, aluminium, tantalum, steel, or of a non-metallic material from the group of graphite, carbon composite, ceramic.
EP03007602A 2002-04-09 2003-04-02 High-frequency-type electron source, in particular neutralizer Expired - Lifetime EP1353352B1 (en)

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Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7498592B2 (en) * 2006-06-28 2009-03-03 Wisconsin Alumni Research Foundation Non-ambipolar radio-frequency plasma electron source and systems and methods for generating electron beams
DE102007036592B4 (en) * 2007-08-02 2014-07-10 Astrium Gmbh High frequency generator for ion and electron sources
JP4925132B2 (en) * 2007-09-13 2012-04-25 公立大学法人首都大学東京 Charged particle emission device and ion engine
DE102007044070A1 (en) * 2007-09-14 2009-04-02 Thales Electron Devices Gmbh Ion accelerator assembly and suitable high voltage insulator assembly
CN102767497B (en) * 2012-05-22 2014-06-18 北京卫星环境工程研究所 Fuel-free spacecraft propelling system based on spatial atomic oxygen and propelling method
CN102797656B (en) * 2012-08-03 2014-08-13 北京卫星环境工程研究所 Air breathing type helicon wave electric propulsion device
CN106672267B (en) * 2015-11-10 2018-11-27 北京卫星环境工程研究所 Propulsion system and method based on space elemental oxygen and matter interaction
CN106941066B (en) * 2017-03-22 2018-07-06 中山市博顿光电科技有限公司 The radio-frequency ion source averager that a kind of ionization effect is stablized
GB2573570A (en) * 2018-05-11 2019-11-13 Univ Southampton Hollow cathode apparatus
CN108882495B (en) * 2018-06-08 2021-02-19 鲍铭 Method for generating neutrons by restraining plasma through high-frequency alternating current electric field
CN111734593B (en) * 2020-06-24 2023-01-31 电子科技大学 Ion neutralizer based on cold cathode
CN114302548B (en) * 2021-12-31 2023-07-25 中山市博顿光电科技有限公司 Radio frequency ionization device, radio frequency neutralizer and control method thereof

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2633778C3 (en) * 1976-07-28 1981-12-24 Messerschmitt-Bölkow-Blohm GmbH, 8000 München Ion thruster
DE2804393A1 (en) * 1978-02-02 1979-08-09 Christiansen Jens METHOD FOR GENERATING HIGH PULSED ION AND ELECTRON CURRENTS
FR2480552A1 (en) * 1980-04-10 1981-10-16 Anvar PLASMA GENERATOR
US4684848A (en) * 1983-09-26 1987-08-04 Kaufman & Robinson, Inc. Broad-beam electron source
JP2531134B2 (en) * 1986-02-12 1996-09-04 株式会社日立製作所 Plasma processing device
US4954751A (en) * 1986-03-12 1990-09-04 Kaufman Harold R Radio frequency hollow cathode
GB8905073D0 (en) * 1989-03-06 1989-04-19 Nordiko Ltd Ion gun
US5003226A (en) * 1989-11-16 1991-03-26 Avco Research Laboratories Plasma cathode
EP0789506B1 (en) * 1996-02-09 2004-12-29 Ulvac, Inc. Apparatus for generating magnetically neutral line discharge type plasma
JP3967050B2 (en) * 1999-10-25 2007-08-29 三菱電機株式会社 Plasma generator
US6291940B1 (en) * 2000-06-09 2001-09-18 Applied Materials, Inc. Blanker array for a multipixel electron source

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