High power plasma switch with active magnetic cut-off control

Abstract

High fidelity plasma switch for cut-off of high voltage and / or high current power to enable the operation of high frequency high fidelity high current and substantially high voltage pulse supply of electrical power using a source of high voltage and high current; a plasma discharge device; an outlet sensor; and a control switch, wherein the plasma discharge device comprises: a vacuum chamber; a means of producing a high vacuum in said vacuum chamber; a means of introducing a gas into said vacuum chamber; inlet and outlet electrodes within said vacuum chamber posed to create a 'spark gap'; and an at least one electromagnet configured to produce a magnetic field in the vacuum chamber that cuts off plasma discharge between the electrodes.

Description

[0001] HIGH POWER PLASMA SWITCH WITH ACTIVE MAGNETIC

[0002] CUT-OFF CONTROL

[0003] FIELD OF THE INVENTION

[0004] The present invention generally relates to high voltage and high current switch systems, and in particular switch systems for producing relatively rapid pulses.

[0005] BACKGROUND OF THE INVENTION

[0006] High power switches that operate via plasma discharge are known in the art dating back to the beginning of the electronic age presenting variations in accordance with operational aspects in and to which the switch is to be employed. The nature of the plasma; the strength or presence of a vacuum; the shape and arrangement of the electrodes; the nature of the grid control unit; the materials from which the electrodes are fabricated, would be just some affecting perspectives. Essentially, such devices exploit the electrical and magnetic properties of the plasma through which they operate and are applied in order to switch or rectify.

[0007] Numerous prior art examples to such switch systems, such as a mercury-arc rectifier device referred to as the “tungar bulb ” is disclosed in US1385895A, itself adapted from the invention disclosed in US682692A, and a diode disclosed in US803684A. These devices lead to the invention of the “thyratron ”, as described in ISSN: 2330-9431. where a similarly structured device was filled with a gas, such that the operation could exploit plasma conductivity to work with much greater currents than its predecessors. A pulse -operated and hydrogen filled variation of the thyratron was adapted to produce the “tacitron ”, disclosed in US2975319A. Many more variants of these devices and associated methods were developed and disclosed and are well known in the field. Employing magnetic fields to further manipulate plasma has also been developed in the field as a general class of solution strategies for a range of problems, operating on the basis that plasmas are magnetic and thus their structure and physical properties are affected by the magnetic fields in which they operate. For example, the rectifier taught in US2182736 employs a magnet to increase efficiency, whilst US2604977A employs magnets for both rectification and decreasing “offswitching time The “crossatron ”, a product developed from inventions disclosed in US4596945A and US4247804A utilized permanent magnets to produce a cusp field, in order to confine the plasma generated, and could be operated as both a modulator and a switch. Similarly, the invention disclosed in US4406952A teaches the employment of a plasma focus effect used to interrupt high voltage charging current supplied by an inductive energy storage system and discharge to an outlet.

[0008] Improvements to the “crossatron ” were developed and disclosed in US5075594A in a device referred to as the “hollatron ”, which utilized a hollow thermo-ionic cathode that eliminated the need for permanent magnets for confining plasma with a cusp field, and could produce a voltage drop an order of magnitude lower than the crossatron. Electrode design would be further explored in the invention disclosed in US5336975A, using a second grid electrode and a permanent magnet stack for plasma confinement, among other inventive features.

[0009] While magnetic cut-off, enabled partially but inadequately by the prior art, essentially refers to a drop in voltage with a high fidelity, said cut-off represents just one part of a pulse cycle. In this sense, the aforementioned inadequacy of the prior art for high fidelity cut-off times of high power voltage necessarily produces a similar inadequacy in the frequency at which a pulse cycle can be operated with said high power voltage. The field of high voltage and more so high current electronics, in which devices of the art may be applied in lasers, plasma chambers or supply line testing, are thus all limited by the lack of available knowledge taught in the art for: high frequency; high fidelity; high voltage; and high current pulses of electrical power supply. The employment of magnets to facilitate faster “off switching” times, herein referred to as “cut-off’ times, operates on the basis that plasma both responds to and creates magnetic fields, and thus when used as a switch it can continue to create a magnetic field that maintains discharge current even when it is switched off. These phenomena are referred to in the art as ‘self-triggering phenomena’ and can produce current decays that may be unfavorable for high current and substantially high voltage applications where relatively rapid and well-defined pulses of high voltage and / or high current are required.

[0010] It is an object of the present invention to, inter alia, overcome said self-triggering phenomena, among other limitations of the art, in order to realize a switch capable of high fidelity cut-off of high voltage and / or high current power, and thus to enable the operation of high frequency high fidelity high current and substantially high voltage pulse supply of electrical power.

[0011] SUMMARY OF THE INVENTION

[0012] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, devices and methods which are meant to be exemplary and illustrative and not limiting in scope. In various embodiments, one or more of the above -described problems have been reduced or eliminated, while other embodiments are directed to other advantages or improvements.

[0013] The present invention substantially introduces the following aspects: a source of high voltage and high current (it being appreciated that high voltage in the context of the invention relates to such power rates for generating particle beams, producing electrical arcs, ignition, operating amplifier tubes as well as other plasma related applications and operations); a plasma discharge device; an outlet sensor; and a control switch, wherein the plasma discharge device comprises: a vacuum chamber; a means of producing a high vacuum in said vacuum chamber; a means of introducing a gas into said vacuum chamber; inlet and outlet electrodes within said vacuum chamber composed of tungsten or other refractive materials posed in relation to each other (interspace termed ‘spark gap’ defined by spatial terms); and an at least one electromagnet configured to produce a magnetic field in the vacuum chamber that cuts off plasma discharge between the electrodes. It being appreciated that the invention is operable whilst the source of high voltage and high current is mainly characterized by high current capabilities and various different, not necessarily high, voltage rates.

[0014] According to another aspect of the present invention, the system comprises a secondary power source, and is configured in an arrangement wherein: the source of high voltage and high current is in communication with the inlet electrode, said secondary power source is in communication with the control switch, the outlet sensor is in communication with the outlet electrode; the outlet sensor is in communication with the control switch; and the control switch is in communication with said secondary power source which discharges to the at least one electromagnet.

[0015] According to another aspect of the present invention, the secondary power source is at least one capacitor bank.

[0016] According to another aspect of the present invention, the at least one electromagnet is at least one coil of electromagnets surrounding the vacuum chamber.

[0017] According to another aspect of the present invention, the source of high voltage and high current providing high electrical current to the inlet electrode while producing a plasma in the vacuum chamber mediates a discharge to the outlet electrode, and wherein said plasma-mediated discharge can be cut off by generation of an electromagnetic field produced by the at least one electromagnet as powered by the secondary power source and controlled by the control switch when triggered by the outlet sensor.

[0018] According to another aspect of the present invention, the peak strength of the electromagnetic field generated by the at least one electromagnet is produced between 1 and 5 microseconds after the opening of the control switch. According to another aspect of the present invention, the strength of electromagnetic field generated by the at least one electromagnet has a magnetic strength of at least 0.5 Tesla in the vacuum chamber .According to another aspect of the present invention, the topology of the electromagnetic field generated by the at least one electromagnet is structured coaxially within the vacuum chamber.

[0019] According to another aspect of the present invention, the means of producing a high vacuum in a vacuum chamber is operated to produce a vacuum, having a pressure between 0.001 and 0.1 torr.

[0020] According to another aspect of the present invention, the means of introducing a gas into the vacuum chamber introduces gas into the vacuum chamber, thereby controlling the pressure of the gas introduced into the gas chamber. Persons skilled in the art will appreciate that the introduction of various different gases injected at various chamber pressures can facilitate the generation of plasma arcs with different properties, which the present invention can operate to pass current between the inlet and outlet electrodes. Light gases, in particular hydrogen and deuterium, can be inserted by the means of introducing gas into the vacuum chamber into said vacuum chamber, and the plasma formed therefrom can be operated by the present invention to achieve a desirous switching operation. Heavier gases, such as sulfur hexafluoride, may also be inserted into the vacuum chamber by the means of introducing gas into the vacuum chamber, from which the present invention can produce a plasma arc from, and which - like the aforementioned light gases - can be controllable by the magnetic cut-off mechanism.

[0021] According to another aspect of the present invention, the control switch activates the at least one electromagnet autonomously in response to the outlet sensor signal.

[0022] According to another aspect of the present invention, the inlet and outlet electrodes within the vacuum chamber are composed of tungsten or other refractive materials posed in relation to each other According to another aspect of the present invention, the inlet electrode is provided with a high voltage from the source of high voltage and high current, thereby producing a plasma within the vacuum chamber substantially between the inlet and outlet electrode, providing a path for current to flow therebetween. Persons skilled in the art will appreciate that various other general methods for the generation of plasma in a vacuum chamber are known in the art.

[0023] According to another aspect of the invention, a method for the provision of high voltage and high current pulses comprises the steps: (a) configuring a source of high voltage and high current; (b) configuring a plasma discharge device, itself comprising: a vacuum chamber; a means of producing a high vacuum in a vacuum chamber; a means of introducing a gas into a vacuum chamber; inlet and outlet electrodes within a vacuum chamber; and at least one electromagnet configured to produce a magnetic field in the vacuum chamber that cuts off plasma discharge between the electrodes, wherein the inlet electrode of the plasma discharge device is in communication with the source of high power and high current, (c) configuring a secondary power source in communication with the at least one electromagnet of the plasma discharge device; (d) configuring an outlet sensor in communication with the outlet electrode of the plasma discharge device; (e) configuring a control switch controlling the communication between the secondary power source and the at least one electromagnet of the plasma discharge device; (f) producing a vacuum in the vacuum chamber of the plasma discharge device; (g) providing high voltage and high current to the inlet of the plasma discharge device, thereby producing a plasma between the inlet and outlet electrodes and transferring high voltage and high current therebetween; (h) sensing at the outlet sensor a threshold change in voltage or in current and communicating a signal to the control switch therefrom; (i) opening the control switch to provide power from the secondary power source to the at least one electromagnet of the plasma discharge device, whereby the generation of a magnetic field by the at least one electromagnet generates a magnetic field that accelerates the plasma between the inlet and outlet electrodes away therefrom, thereby disrupting high voltage and high current transference therebetween.

[0024] According to another aspect of the invention, wherein the control switch operates autonomously in response to the signal obtained from the outlet sensor. BRIEF DESCRIPTION OF THE FIGURES

[0025] Some embodiments of the invention are described herein with reference to the accompanying figures. The description, together with the figures, makes apparent to a person having ordinary skill in the art how some embodiments may be practiced. The figures are for the purpose of illustrative description and no attempt is made to show structural details of an embodiment in more detail than is necessary for a fundamental understanding of the invention.

[0026] In the Figures:

[0027] FIG. 1 constitutes an overview of the components for the present invention in communication with each other, according to some embodiments.

[0028] FIG.2 constitutes a graph describing current vs. time for the cut-off of a conventional plasma switch, which lacks a controlled magnetic active cut-off as taught by the present invention.

[0029] FIG. 3 constitutes a graph describing current vs. time for the cut-off of a conventional plasma switch with controlled magnetic active cut-off as taught in the present invention, according to some embodiments.

[0030] FIG. 4 constitutes a cross section perspective view of the plasma switch of the present invention with a central spark gap parallel to the plasma induced magnetic field lines in a cylindrical vacuum chamber, with electromagnetic coils external thereto, according to some embodiments.

[0031] FIGS. 5A-D constitute perspective views of the plasma switch of the present invention with a central spark gap perpendicular to plasma induced magnetic field lines, and electromagnetic coils external to a cylindrical vacuum chamber, according to some embodiments.

[0032] FIGS. 6A-C constitute perspective views of the plasma switch of the present invention with a spark gap perpendicular to plasma induced magnetic field lines, and electromagnetic coils internal to the vacuum chamber, wherein the spark gap is configured distally to the electromagnetic coils, according to some embodiments.

[0033] FIGS. 7A-D constitute perspective views of the plasma switch of the present invention with a central spark gap perpendicular to plasma induced magnetic field lines, and concave electromagnetic coils external to a dumbbell vacuum chamber, according to some embodiments.

[0034] FIGS. 8A-C constitute perspective views of the plasma switch of the present invention with a spark gap perpendicular to plasma induced magnetic field lines, and concave electromagnetic coils external to a lightbulb-shaped vacuum chamber, wherein the spark gap is arranged distally to the electromagnetic coils, according to some embodiments.

[0035] FIGS. 9A-C constitute cross section views of some embodiments of the electrodes and spark gaps within the plasma switch of the present invention, according to some embodiments.

[0036] FIGS. 10A-C, show three views of computer calculated simulations of current in magnetic fields within the spark gap of the present invention, according to some embodiments.

[0037] DETAILED DESCRIPTION OF SOME EMBODIMENTS

[0038] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components, modules, units and / or circuits have not been described in detail so as not to obscure the invention. Some features or elements described with respect to one embodiment may be combined with features or elements described with respect to other embodiments. For the sake of clarity, discussion of same or similar features or elements may not be repeated. Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed simultaneously, at the same point in time, or concurrently.

[0039] The present invention discloses a system and method for the high fidelity control of a high voltage high current switch.

[0040] The term “duty cycle ”, as used herein, refers to the cycle of “off” and “on ” phases of a switch when operated cyclically, which together may produce a series of pulses with a particular frequency. The present invention teaches a system and method of finely controlling these phases, in particular by providing a high fidelity means of producing an “off” phase. The frequency of the duty cycle produced by assemblies in which the system of the present invention is disposed relies heavily on the electronic demands of the device(s) receiving voltage and current from the outlet electrode, but can - facilitated by the high fidelity magnetic cut-off taught in the present invention - be further modulated by configuration of the control switch (among other features) of the present invention. The maximum limit for rapidity of the pulse cycle, i.e. the highest possible frequency of the “off” and “on ” periods of the pulse cycle, is - in many configurations - directly related to the speed and fidelity of the cut-off operation, which the present invention teaches a system and method to finely control.

[0041] The term “sparkgap ”, as used herein, refers to the space between two electrodes over which a current may be transmitted when electrical and magnetic conditions are favorable to do so. Persons skilled in the art will appreciate that a spark gap has an inherent axis, a line in three-dimensional space that connects the points of highest average charge concentration on the surfaces of each of the electrodes facing toward the spark gap-

[0042] The term “Q-factor” , as used herein, refers to the dimensionless parameter of oscillating systems describing the extent to which oscillations are damped. In the specific context of the present invention the term “Q- factor” is used to describe the extent of damping, that is the continuous reduction in the amplitude oscillations, of alternating current passing from the inlet electrode to the outlet electrode, in embodiments of the present invention wherein alternating current is used.

[0043] According to some embodiments, the outlet sensor comprises a “zero current switch”, wherein said zero current switch is modulated when the current passing through its inlet is equivalent to zero. According to other embodiments of the present invention, the outlet sensor is configured to sense the voltage above or below a threshold value at the outlet electrode or other components connected thereto, wherein voltage rising / decreasing above / below a threshold value indicates a predetermined cutoff.

[0044] According to some embodiments, the at least one electromagnet is a series of electromagnets operable together.

[0045] It is a benefit of the present invention that the secondary power source is distinct from that of the source of high voltage and high current, and can be - according to some embodiments - a capacitor bank. By employing a sperate circuit to that of the main power supply, the present invention affords additional benefits to the mitigation of the self-triggering phenomena that limit other devices taught in the art.

[0046] According to some embodiments, the control switch is a semiconductor switch (or an array thereof) configured to provide the optimal voltage and current to the electromagnet required to cut off the plasma discharge in the vacuum chamber. Commercial semiconductor based switches are typically rated to switching speeds and frequencies at least an order of magnitude below the switching speed afforded by the present invention. While this does not mean that said semiconductor based switches (or arrays thereof) cannot be used at high speeds in the control circuitry of the present invention, it does indicate that the state of the art - and thus the expertise of persons having ordinary skill therein - is limited with respect to the use and configuration of commercially available electrical components in high frequency power electronics applications. According to some embodiments of the present invention, plasma is generated within the vacuum chamber from gas introduced by the means of introducing gas into the vacuum chamber, wherein said gas is ionized by the high voltage gap in the spark gap between the inlet an outlet electrodes, and said plasma providing a path for current to flow between the inlet and outlet electrode. In embodiments of the invention wherein plasma is generated as a result of the high voltage gap, no dedicated means of a plasma generation need be provided, however, in other embodiments, such a dedicated means of plasma generation can confer a number of specific advantages, including: independence of switch operation from voltage; independence of duty cycle frequency from the variations in the power supply; among others benefits.

[0047] According to other embodiments of the present invention, a dedicated means of plasma generation comprises at least one high powered laser configured to provide a laser beam within the vacuum chamber, said laser beam(s) being aimed at an ablation substrate positioned close to the spark gap between the two electrodes, such that when the laser(s) is / are fired at the ablation substrate, some of said substrate is ablated resulting in plasma formation at the spark gap, providing a current to pass between the inlet an outlet electrode, wherein the control of said laser(s) is in communication with the control switch. According to other embodiments of the present invention, the ablation substrate is one or both of the two electrodes. According to other embodiments of the present invention, the ablation substrate is a dedicated sacrificial material suspended within the chamber.

[0048] According to other embodiments of the present invention, a dedicated means of plasma generation comprises a high power radio frequency (RF) emitter, said RF emitted having a dedicated power supply and control means, said control means being in communication with the control switch.

[0049] Reference is made to FIG. 1 which constitutes an overview of the components for the present invention in communication with each other, according to some embodiments. A source of high voltage electrical current 100 is in communication with the inlet of spark gap electrodes 110, the outlet of the spark gap electrodes 110 is in communication with: the outlet 120; an outlet sensor 130; and the inlet to a control switch 140. The outlet of the control switch is in communication with inlet of a secondary power source, in the case illustrated in FIG. 1 said secondary power source being a capacitor bank 150, and the outlet of the capacitor bank 150 is in communication with the electromagnet 160, and the electromagnet applies a magnetic field to the plasma thus providing active cut-off functionality. According to some embodiments, high voltage electrical current is provided by the source of high voltage electrical current 100 to the spark gap electrodes 110, which in turn provide high voltage electrical current to both the outlet 120 and to the capacitor bank 150 through the control switch 140. When the outlet sensor 130 senses a threshold voltage or current, it communicates a signal to the control switch 140, which functions to initiate the discharge of the voltage stored in the capacitor bank 150 to the electromagnet 160, which in turn produces a magnetic field applied to the plasma thereby cutting off the current flowing within and thus closing the switch rapidly and without risk of plasma self-triggering phenomena, producing a well-defined pulse of high voltage electrical current to the outlet 120. According to some embodiments control switch 140 is autonomously operated. According to some embodiments, the initial threshold sensed by the outlet sensor is a minimum threshold current, which the current flowing between the inlet and outlet electrode will naturally reach as a result of decay, depending on the Q-factor presented.

[0050] Reference is now made to FIG. 2, which constitutes a graph describing current vs. time for the cut-off of a conventional plasma switch, which lacks a controlled magnetic active cut-off as taught by the present invention. During the period prior to the switch opening 200 no voltage is present at the outlet. When the switch is opened, a period of time 210 elapses while voltage is present at the outlet in a generally but not necessarily uniform manner, and the amplitude of the current decays, according to the angle 240, and decreasing in amplitude by the amount 260. When the switch is closed another period of time 220 begins to elapse wherein the voltage at the outlet decays by a larger angle 250. The pulse demonstrated in these three periods is poorly defined due to the voltage decay in period 220 and is thus unsuitable for many industrial applications requiring well-defined pulses of high voltage electrical current. Such a voltage -time profile is conventional for plasma switches due to self -triggering phenomena of the plasma. Persons skilled in the art will appreciate that when - in the preceding language - voltage is discussed that the system is also transmitting said voltage at a high current. In the case illustrated by FIG. 2, the current passed between the inlet and outlet electrodes is alternating, however a similar effect can be observed in direct current switches, wherein the natural decay of current 240 during period 210: the “on ” phase is present, as is the larger decay of the current 250 during the “off” phase, which includes period 220.

[0051] Reference is now made to FIG. 3, which constitutes a graph describing current vs. time for the cut-off of a conventional plasma switch with controlled magnetic active cut-off as taught in the present invention, according to some embodiments. During the period prior to the switch opening 300 no voltage is present at the outlet. When the switch is opened at time 305, a period of time 310 elapses wherein current 301 is present at the outlet in a generally but not necessarily uniform manner, and the amplitude decays according to angle 340, and decreasing in amplitude by the amount 360. When the switch is closed at time 330 another period 320 begins to elapse wherein the voltage is immediately cut. The pulse demonstrated in these three periods is well-defined due to the lack of a voltage decay in period, and is thus suitable for many industrial applications requiring well-defined pulses of high voltage electrical current. This high fidelity voltage -time profile is only available when the active magnetic cut off mechanism eliminates the self -triggering phenomena that cause the voltage decay illustrated in period 220 of FIG. 2. Persons skilled in the art will appreciate that when - in the preceding language - voltage is discussed that the system is also transmitting said voltage at a high current. In the case illustrated by FIG. 3, the current passed between the inlet and outlet electrodes of the present invention is alternating, however a similar effect can be observed in other embodiments of the present invention that operate with direct current, wherein the natural decay 340 of current during period 310: the “on ” phase is present.

[0052] In the provisional application of the present invention, the graphs shown in FIG. 2 and FIG. 3 demonstrated simplified cases with no decay in the current during the “on ” phase. Persons skilled in the art will appreciate that that these graphs represent idealized cases, and that the dynamics illustrated in the present invention are illustrations of the same phenomena that integrate the realistic condition systems with non-ideal Cofactors.

[0053] Reference is now made to FIG. 4, which constitutes a cross section perspective view of the plasma switch of the present invention with a central spark gap parallel to the plasma induced magnetic field lines in a cylindrical vacuum chamber, with electromagnetic coils external thereto, according to some embodiments. Base plates 410 and 430 form the axial ends of a cylindrical vacuum chamber 450 enclosed by a casing 420. Within the vacuum chamber 450, a mount 460 and electrode surface 470 form an inlet electrode, and mount 400 and electrode surface 490 form an outlet electrode, wherein the spark gap between the electrode surfaces 480 is the volume in which plasma discharge forms. Persons skilled in the art will appreciate that the first and second electrode may be configured as cathode and anode, or as anode and cathode, or as simply inlet and outlet electrodes for applications of alternative current. Coils of an electromagnet 440 surround the vacuum chamber and are arranged to produce a magnetic field that prevents the discharge of the plasma within the spark gap 480 between the electrode surfaces 470 and 490.

[0054] According to some embodiments of the invention, such as the illustrated in FIG. 4, the spark gap of the plasma switch is arranged such that the axis between the two electrode surfaces (470 and 490) aligns with the axis of the magnetic field produced by the electromagnetic coils 440. When the electromagnetic coils are activated, the resultant magnetic field accelerates the plasma within the spark gap along this axis and away from the spark gap, cutting off the current between the electrode surfaces (470 and 490). This effect may be further optimized by arranging the electrode surfaces such that the axis of the spark gap 480 is perpendicular to that of the plasma induced magnetic field and / or the electromagnetic coils’ magnetic field, such that when the electromagnetic coils 440 are activated, the plasma is accelerated away from the spark gap 480 in a direction that does not collide with the electrode surfaces 470 and 490. For the sake of brevity and clarity, the base plates shown in FIG. 4 are not shown in other embodiments of the invention shown in other figures, just as other aspects of the present invention are not shown - for the sake of brevity and clarity - in FIG. 4.

[0055] Reference is made to FIGS. 5A-D, which constitute perspective views of the plasma switch of the present invention with a central spark gap perpendicular to plasma induced magnetic field lines, and electromagnetic coils external to a cylindrical vacuum chamber, according to some embodiments. In FIG. 5A, a partial cross section 510 of the plasma switch area within a vacuum chamber 500 is presented, wherein a section of vacuum chamber 500 is surrounded by electromagnetic coils 520 with terminals 521 and 522, and containing the two electrodes 530 and 540 with a spark gap 550 between them, wherein either of said two electrodes can be configured as the inlet electrode and the other as the outlet electrode. The space 560 within the vacuum chamber 500 contains a plasma, the other components required for which - including a means of (a) generating a vacuum, (b) inserting an ionizable gas, and (c) forming a plasma from said gas - are not shown for the purposes of clarity of image and brevity of text. According to some embodiments of the invention, when the electromagnetic coils 520 are activated, the plasma that forms the conductive arc within the spark gap 550 is accelerated by the magnetic field away from the spark gap 550, breaking the current and cutting off the switch with a high fidelity. According to some embodiments, a plurality of terminals 521 and 522 will enable the employment of the invention with the at least one set of electromagnetic coils.

[0056] In FIG. 5B, a top view of the same plasma switch shown in FIG. 5A is shown, in which a vacuum chamber 500 is surrounded by electromagnetic coils 520, and contains two electrodes 530 and 540. In FIG. 5C, a side view of the same plasma switch shown in FIG. 5A is shown, in which a vacuum chamber 500 is surrounded by electromagnetic coils 520, and contains two electrodes 530 and 540 with a spark gap 550 between them, wherein either of said two electrodes can be configured as the inlet electrode and the other as the outlet electrode. In FIG. 5D, a bottom view of the same plasma switch shown in FIG. 5A is shown, in which a vacuum chamber 500 is surrounded by electromagnetic coils 520 with two terminals 521 and 522, and contains two electrodes 530 and 540, wherein either of said two electrodes can be configured as the inlet electrode and the other as the outlet electrode.

[0057] Reference is made to FIGS. 6A-C, which constitute perspective views of the plasma switch of the present invention with a spark gap perpendicular to plasma induced magnetic field lines, and electromagnetic coils internal to the vacuum chamber, wherein the spark gap is configured distally to the electromagnetic coils, according to some embodiments. In FIG. 6A, a partial cross section 610 of the plasma switch area within vacuum chamber 600 is presented, wherein a section of vacuum chamber 600 contains electromagnetic coils 620 with terminals 621 and 622, and contains the two electrodes 630 and 640 with a spark gap 650 between them, wherein either of said two electrodes can be configured as the inlet electrode and the other as the outlet electrode. The space 660 within the vacuum chamber 600 contains a plasma, the other components required for which - including a means of (a) generating a vacuum, (b) inserting an ionizable gas, and (c) forming a plasma from said gas - are not shown for the purposes of clarity of image and brevity of text. According to some embodiments of the invention, when the electromagnetic coils are activated, the plasma that forms the conductive arc within the spark gap 650 is accelerated by the magnetic field away from the spark gap 650, breaking the current and cutting off the switch with a high fidelity. According to some embodiments, a plurality of terminals 621 and 622 will enable the employment of the invention with the series of electromagnetic coils.

[0058] In FIG. 6B, a top view of the same plasma switch shown in FIG. 6A is shown, in which a vacuum chamber 600 contains electromagnetic coils 620, and contains two electrodes 630 and 640. In FIG. 6C, a front view of the same plasma switch shown in FIG. 6A is shown, in which a vacuum chamber 600 contains electromagnetic coils 620, and contains two electrodes 630 and 640 with a spark gap 650 between them.

[0059] According to some embodiments of the invention, the at least one electromagnet is at least one set of electromagnetic coils, and may be arranged externally to the vacuum chamber, thereby preventing any interaction between the plasma and the coils, which may damage to the coils. According to other embodiments of the invention, the electromagnetic coils are arranged internally to the vacuum chamber, which allows for significantly reduced amount of power required to operate the magnetic cut-off functionality.

[0060] Reference is made to FIGS. 7A-D, which constitute perspective views of the plasma switch of the present invention with a central spark gap perpendicular to plasma induced magnetic field lines, and concave electromagnetic coils external to a dumbbell vacuum chamber, according to some embodiments. In FIG. 7A, a front view of the plasma switch is shown, illustrating a dumbbell vacuum chamber 700 a section of which is surrounded by electromagnetic coils 720 having terminals 721 and 722, and contains two electrodes 730 and 740 with a spark gap 750 therebetween, wherein either of said two electrodes can be configured as the inlet electrode and the other as the outlet electrode. According to some embodiments, the concave geometry of the electromagnetic coils 720 produces magnetic field lines that concentrate the accelerating force exerted on components of the plasma in the narrowest portion of the volume contained within said coils, the same portion where a spark gap 750 is operated between two electrodes 730 and 740, such that when the electromagnetic coils 720 are activated with current running from terminals 721 to 722 (or vice versa), the plasma located at the spark gap 750 is accelerated away very rapidly, producing a cut off with an exceptionally high fidelity. According to some embodiments, the dumbbell geometry of the vacuum chamber 700 contains a vacuum and / or a plasma in its internal cavity 760. The space 760 within the vacuum chamber 700 contains a plasma, the other components required for which - including a means of (a) generating a vacuum, (b) inserting an ionizable gas, and (c) forming a plasma from said gas - are not shown for the purposes of clarity of image and brevity of text. According to some embodiments larger volumes 761 and 762 on either side of the narrow portion of internal cavity 760 may be configured with a round geometry to maximize mechanical strength, and contain enough internal volume to disperse the local pressure increases incurred by the acceleration of plasma thereinto. According to some embodiments, a plurality of terminals 721 and 722 will enable the employment of the invention with a series of electromagnetic coils. In FIG. 7B, a perspective view of the same plasma switch shown in FIG. 7A is shown, in which a vacuum chamber 700 contains electromagnetic coils 720, and contains two electrodes 730 and 740. In FIG. 7C, a side view of the same plasma switch shown in FIG. 7A is shown, in which a vacuum chamber 700 contains electromagnetic coils 720, and contains two electrodes 730 and 740 with a spark gap 750 between them. In FIG. 7D, a closeup front view of the same plasma switch shown in FIG. 7A is shown, in which a vacuum chamber 700 contains electromagnetic coils 720, and contains two electrodes 730 and 740 with a spark gap 750 between them.

[0061] Reference is made to FIGS. 8A-C, which constitute perspective views of the plasma switch of the present invention with a spark gap perpendicular to plasma induced magnetic field lines, and concave electromagnetic coils external to a lightbulb-shaped vacuum chamber, wherein the spark gap is arranged distally to the electromagnetic coils, according to some embodiments. In FIG. 8A, a perspective view of the plasma switch is shown, with partial cross section 810, and illustrating a vacuum chamber 800 a section of which is surrounded by electromagnetic coils 820 having terminals 821 and 822, and contains two electrodes 830 and 840 with a spark gap 850 therebetween. According to some embodiments, the concave geometry of the electromagnetic coils 820 produces magnetic field lines that concentrate the accelerating force exerted on components of the plasma in the narrowest portion of the volume contained within said coils, the same portion where a spark gap 850 is operated between two electrodes 830 and 840, such that when the electromagnetic coils 820 are activated with current running from terminals 821 to 822 (or vice versa), the plasma located at the spark gap 850 is accelerated away very rapidly, producing a cut off with an exceptionally high fidelity. According to some embodiments, the lightbulb geometry of the vacuum chamber 800 contains a vacuum and / or a plasma in its internal cavity. The internal cavity within the vacuum chamber 800 contains a plasma, the other components required for which - including a means of (a) generating a vacuum, (b) inserting an ionizable gas, and (c) forming a plasma from said gas - are not shown for the purposes of clarity of image and brevity of text. According to some embodiments the larger volume on one side of the narrow portion of the internal cavity of chamber 800 may be configured with a round geometry to maximize mechanical strength, and contain enough internal volume to disperse the local pressure increases incurred by the acceleration of plasma thereinto. According to some embodiments, a plurality of terminals 821 and 822 will enable the employment of the invention with e series of electromagnetic coils.

[0062] In FIG. 8B, a top view of the same plasma switch shown in FIG. 8A is shown, in which a vacuum chamber 800 contains electromagnetic coils 820, and contains two electrodes 830 and 840. In FIG. 8C, a side view of the same plasma switch shown in FIG. 8A is shown, in which a vacuum chamber 800 contains electromagnetic coils 820, and contains two electrodes 830 and 840 with a spark gap 850 between them. In FIG. 8D, a close up front view of the same plasma switch shown in FIG. 8A is shown, in which a vacuum chamber 800 contains electromagnetic coils 820 and two terminals 821 and 822 thereof.

[0063] By arranging the spark gap at the distal end of the electromagnetic coils, the effect of the magnetic field on the ionized gas can be maximized, as said component of the plasma has mass that can be accelerated by said field, and in doing so - according to some embodiments - further improve the fidelity of the cut-off operation.

[0064] FIGS. 9A-C constitute cross section views of some embodiments of the electrodes and spark gaps within the plasma switch of the present invention. The distance of the spark gap and the surface areas of the electrodes at its border are significant factors in the operation of the magnetic cut-off functionality taught in the present invention. According to some embodiments of the invention, different electrode geometries exploit these factors to further optimize the fidelity of the cut-off operation.

[0065] In FIG. 9A, a cross-section of a near-conventional electrode pair is presented, wherein electrodes 911 and 921 have widened surface areas 931 and 941 and a uniform spark gap 951 between them. In a case more complex than that of FIG. 9A, a cross-section of a wavy electrode pair is taught in FIG. 9B, wherein electrodes 912 and 922 have widened and wavy surface areas 932 and 942 and a spark gap 952 between them, wherein the widened and wavy surface areas 932 and 942 are larger than that of the widened surface areas of near-conventional electrodes of similar nominal width. In a yet more complex than that of FIG.s 9A — B, a cross-section of a “ball-and-socket” electrode pair is taught in FIG. 9C, wherein electrodes 913 and 923 have corresponding “ball” and “socket” surface areas 933 and 943, respectively and a spark gap 953 between them.

[0066] According to some embodiments, the geometry of the electrodes - including those taught in FIG. 9 - are optimized at their surfaces perpendicular with the axis of the plasma induced magnetic field such that plasma being accelerated away from the spark gap collides with the electrodes as little as possible. For example, the geometry of said electrodes may include inwardly tapered surfaces of the cross sections shown in FIG. 9 to minimize the collisions of plasma with the surface, and even to optimize the flow of plasma to minimize turbulence, further improving the fidelity of the magnetic cut-off operation.

[0067] Reference is made to FIGS. 10A-C, which show three views of current simulations in magnetic fields within the spark gap of the present invention, according to some embodiments. In FIG. 10A, a perspective view is shown of a portion of the present invention including the spark gap between two electrodes 1011 and 1012, the latter of which is configured as the inlet electrode. A section of the vacuum chamber 1040 is shown, as is the distribution of the strength of the magnetic field over a cut plane 1015. Magnetic field lines 1020 indicate that the magnetic field is perpendicular to the axis between the electrodes 1011 and 1012, thus when the magnetic field is induced by the magnetic cut-off mechanism, charge carriers flowing from electrode 1012 to 1011 are influenced by said field in such a manner that they are deflected 1030 away from reaching 1011, thereby cutting the circuit.

[0068] In FIG. lOB the same simulation shown in FIG. 10A is presented, from a perspective over which the variations in the density of the magnetic flux on the cut plane 1015 is shown more clearly, wherein greatest variation in said magnetic flux density is found in the region proximal to the electrodes, wherein density varies from 0.15 Tesla 1046 closest to the intersection of the electrodes 1011 and 1012 to the chamber wall, to 0.2 Telsa 1045, to 0.25 Tesla 1044, to 0.3 Tesla 1043 in a larger region expanding from the face of the electrodes facing the other electrode, to 0.35 Tesla 1044 throughout much of the spark gap, to 0.4 Tesla 1043 in regions of the vacuum chamber less proximal to the electrodes. The magnetic flux density distribution shown in FIGS. 10A-C is representative of an embodiment of the present invention, in many other embodiments the range of magnetic flux densities is much larger, and reaches much high values.

[0069] In FIG. 10C a side perspective of the same simulation shown in FIGS. 10A-B is shown with the distribution of magnetic flux density on the cut plane 1015. From the view shown in FIG. 10C, the direction of the deflection 1030 of charge carriers in their path from electrode 1012 to electrode 1011 is clear, wherein said deflection prevents the transference of high voltage and high current between said electrodes.

[0070] Although the present invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention will become apparent to persons skilled in the art upon reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention.

Claims

We claim:1) A high voltage plasma switch system, comprising: a) a source of high voltage and high current; b) a plasma discharge device; c) an outlet sensor; and d) a control switch, wherein the plasma discharge device comprises: a vacuum chamber; a means of producing a high vacuum in said vacuum chamber; a means of introducing a gas into said vacuum chamber; inlet and outlet electrodes within said vacuum chamber composed of tungsten or other refractive materials posed in relation to each other; and an at least one electromagnet configured to produce a magnetic field in said vacuum chamber that cuts off plasma discharge between the electrodes.2) The system of claim 1 comprising a secondary power source, wherein the source of high voltage and high current is in communication with the inlet electrode; said secondary power source is in communication with the control switch; the outlet sensor is in communication with the outlet electrode; the outlet sensor is in communication with the control switch; and the control switch is in communication with said secondary power source which discharges to the at least one electromagnet.3) The system of claim 1 , wherein the secondary power source is at least one capacitor bank.4) The system of claim 1, wherein the at least one electromagnet is at least one coil of electromagnets surrounding the vacuum chamber.5) The system of claim 2, wherein the source of high voltage and high current providing high voltage and high current to the inlet electrode while producing a plasma in the vacuum chamber mediates a discharge to the outlet electrode, and wherein said plasma-mediated discharge can be cut off bygeneration of an electromagnetic field produced by the at least one electromagnet as powered by the secondary power source and controlled by the control switch when triggered by the outlet sensor.6) The system of claim 5, wherein the peak strength of the electromagnetic field generated by the at least one electromagnet is produced between 1 and 5 microseconds after the opening of the control switch.7) The system of claim 5, wherein the strength of electromagnetic field generated by the at least one electromagnet has a magnetic strength of at least 0.5 Tesla in the vacuum chamber.8) The system of claim 7, wherein the topology of the electromagnetic field generated by the at least one electromagnet is structured coaxially within the vacuum chamber.9) The system of claim 5, wherein the means of producing a high vacuum in vacuum chamber is operated to produce a vacuum having a pressure between 0.001 and 0.1 torr.10) The system of 9, wherein the means of introducing a gas into the vacuum chamber introduces gas into the vacuum chamber thereby controlling the pressure of the gas introduced into the gas chamber.11) The system of claim 5, wherein the control switch activates the at least one electromagnet autonomously in response to the outlet sensor signal.12) The system of claim 5, wherein inlet and outlet electrodes within the vacuum chamber are composed of tungsten or other refractive materials posed in relation to each other13) A method for the provision of high voltage and high current pulses, comprising the steps: a) configuring a source of high voltage and high current; b) configuring a plasma discharge device, itself comprising: a vacuum chamber; a means of producing a high vacuum in a vacuum chamber; a means of introducing a gas into a vacuum chamber; inlet and outlet electrodes within a vacuum chamber; and at least one electromagnet configured to produce a magnetic field in the vacuum chamber that cuts off plasma discharge between theelectrodes, wherein the inlet electrode of the plasma discharge device is in communication with the source of high power and high current; c) configuring a secondary power source in communication with the at least one electromagnet of the plasma discharge device; d) configuring an outlet sensor in communication with the outlet electrode of the plasma discharge device; e) configuring a control switch controlling the communication between the secondary power source and the at least one electromagnet of the plasma discharge device; f) producing a vacuum in the vacuum chamber of the plasma discharge device; g) providing high voltage and high current to the inlet of the plasma discharge device, thereby producing a plasma between the inlet and outlet electrodes and transferring high voltage and high current therebetween; h) sensing at the outlet sensor a threshold change in voltage or in current and communicating a signal to the control switch therefrom; i) opening the control switch to provide power from the secondary power source to the at least one electromagnet of the plasma discharge device, whereby the generation of a magnetic field by the at least one electromagnet generates a magnetic field that accelerates the plasma between the inlet and outlet electrodes away therefrom, thereby disrupting high voltage and high current transference therebetween.14) The method of claim 12, wherein the control switch operates autonomously in response to the signal obtained from the outlet sensor.

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