Abstract: A plasma torch rotation assembly for relieving stress on a lead. The rotation assembly can include an outer housing, which can have a mounting surface adapted to be fixedly coupled to a torch mount. The rotation assembly can include an inner component disposed at least partially within the outer housing, and a bearing structure disposed between the outer housing and the inner component. The bearing structure can facilitate rotational movement of the outer housing relative to the inner component, about a longitudinal axis of the rotation assembly. The rotation assembly can include a torch adapter disposed near a first end of the inner component. The torch adapter can be adapted to mate with a plasma arc torch. The rotation assembly can include a receiving portion disposed at a second end of the inner component, the receiving portion adapted to receive at least a portion a lead.

Abstract: Embodiments of field enhanced inductively coupled plasma reactors and methods of use of same are provided herein. In some embodiments, a field enhanced inductively coupled plasma processing system may include a process chamber having a dielectric lid and a plasma source assembly disposed above the dielectric lid. The plasma source assembly includes one or more coils configured to inductively couple RF energy into the process chamber to form and maintain a plasma therein, one or more electrodes configured to capacitively couple RF energy into the process chamber to form the plasma therein, wherein the one or more electrodes are electrically coupled to one of the one or more coils, and an RF generator coupled to the one or more inductive coils and the one or more electrodes. In some embodiments, a heater element may be disposed between the dielectric lid and the plasma source assembly.

Abstract: A number of RF power transmission paths are defined to extend from an RF power source through a matching network, through a transmit electrode, through a plasma to a number of return electrodes. A number of tuning elements are respectively disposed within the number of RF power transmission paths. Each tuning element is defined to adjust an amount of RF power to be transmitted through the RF power transmission path within which the tuning element is disposed. A plasma density within a vicinity of a particular RF power transmission path is directly proportional to the amount of RF power transmitted through the particular RF power transmission path. Therefore, adjustment of RF power transmitted through the RF power transmission paths, as afforded by the tuning element, enables control of a plasma density profile across a substrate.

Abstract: A system for supplying fluids to a plasma arc torch includes a single-gas power supply for regulating supply of electrical power to the plasma arc torch and for regulating supply of a first fluid to the plasma arc torch, a flow regulator for regulating supply of a second fluid to the plasma arc torch, and a first pressure-actuated valve disposed between the flow regulator and the plasma arc torch. The pressure-actuated valve shuts off supply of the second fluid to the torch when the first pressure-actuated valve is closed and allows the second fluid to be supplied to the torch when the first pressure-actuated valve is open. The first pressure-actuated valve is structured and arranged to be opened by pressure of the first fluid being supplied to the torch and to be closed when the first fluid is not being supplied to the torch. The system can also include a second pressure-actuated valve in the supply line for the first fluid, which is opened by pressure of the second fluid being supplied to the torch.

Abstract: A system and method for start flow approach control for a proportional valve in a plasma cutter is provided that includes a controller configured to determine a target gas pressure set point for a plasma cutting operation and determine a ramp pressure set point offset from the target gas pressure set point. The controller is also configured to apply a full-open drive signal to an air pressure-closing proportional valve and monitor a pressure of gas flow output from the air pressure-closing proportional valve via a sensing device. The controller is further configured to apply a ramping drive signal to the air pressure-closing proportional valve after the pressure of the gas flow has reached the ramp pressure set point and apply a target-pressure drive signal to the air pressure-closing proportional valve after the pressure of the gas flow has reached the target gas pressure set point.

Abstract: A method of determining a failure event of consumable for a plasma torch is provided. The method includes monitoring at least one of an operating current or an operating voltage during a transfer arc mode of the plasma arc torch. The method also includes determining when at least one parameter associated with the operating current or the operating voltage exceeds a tolerance threshold for a time period indicative of the failure event. The method further includes shutting off at least one of the operating current or the operating voltage of the plasma arc torch when the at least one parameter exceeds the tolerance threshold for the time period.

Abstract: A device for sustaining a plasma in a torch is provided. In certain examples, the device comprises a first electrode configured to couple to a power source and constructed and arranged to provide a loop current along a radial plane of the torch. In some examples, the radial plane of the torch is substantially perpendicular to a longitudinal axis of the torch.

Abstract: A system for automatically controlling an operating mode of a plasma torch includes a plasma torch that is connected to a power source and a controller. The controller is configured to automatically determine a desired operating mode of the plasma torch and deliver a power signal to the plasma torch based on the desired operating mode.

Abstract: A plasma arc power supply with a simple structure and its control method enable shifting from a pilot arc to a main arc. A plasma arc power supply used in a plasma arc apparatus that processes a workpiece by forming a pilot arc between a main electrode and a nozzle electrode and subsequently forming a main arc between the main electrode and the workpiece includes N direct current power supply units (N?2) having negative terminals connected to the main electrode and positive terminals to the workpiece, and a switch between the fourth power supply unit and the workpiece. The fourth power supply unit is connected to cause the nozzle electrode to have an opposite polarity to the main electrode. When the switch is open, the fourth power supply unit supplies a small current between the main electrode and the nozzle electrode while forming a pilot arc between them.

Abstract: A system and method for over-voltage protection is described. In one embodiment of the invention, an apparatus includes an output port configured to deliver power to a plasma chamber to ignite a plasma. The apparatus also includes a shunt switch in parallel with the output port and a processor configured to receive an indicator of an arc in the plasma. The processor is configured to close the shunt switch for a period of time to divert current away from the arc. The processor is also configured to trigger a pulse of the shunt switch to limit a voltage of an increasing voltage condition associated with the arc.

Abstract: The invention relates to a vapor plasma burner (6) comprising a burner handle (6a) and a burner base (6b). Inside the burner base (6b), a liquid feed pipe (32), a heating device (26), a burner chamber (27), a cathode (22), connected to a cathode support (28), and an anode (24) which is configured as a nozzle (23) and has an exit opening (25) are arranged. The invention also relates to a cathode (22) and to a nozzle (23) for such a vapor plasma burner (6). The aim of the invention is to provide a vapor plasma burner (6) that can be optimally ignited and the wearing parts of which can be easily removed.

Abstract: In a processing apparatus for performing a specified process on a target object at a predetermined process pressure, the apparatus includes an evacuable processing chamber having a gas exhaust port formed in a bottom portion thereof; a mounting table provided within the processing chamber for holding the target object; a pressure control valve connected to the gas exhaust port, the pressure control valve including a slide-type valve body for changing an area of an opening region of a valve port; and a gas exhaust system connected to the pressure control valve. The pressure control valve is eccentrically arranged such that a center axis of the mounting table lies within an opening region of the pressure control valve formed over a practical use region of a valve opening degree of the pressure control valve.

Abstract: In some aspects of the invention, a system for operating a plurality of plasma and/or induction heating processing systems includes an operating unit that has a display device on which a graphic user interface can be displayed, at least two power generators that supply power to a plasma process or an induction heating process, and a network that connects the operating unit to the power generators to transmit signals between the operating unit and the power generators. The graphic user interface includes a static region and a dynamic region, and a selection device for selecting information to be displayed in the dynamic region.

Abstract: A system is provided that includes a torch power unit. The torch power unit includes a monitor and/or control configured to determine a temperature of a component of the torch power unit based on the one or more inputs without a direct temperature measurement of the component. A method of operation is provided that includes receiving one or more inputs associated with a device, and estimating a temperature of the device based on the one or inputs without directly measuring temperature of the device. A tangible machine-readable medium is provided that includes code for determining a thermal capacity of the device, code for determining a thermal resistance of the device, and code for determining a temperature of the device based on thermal capacity and the thermal resistance method.

Abstract: An improved torch providing high visibility of the work zone to the operator, an increased viewing angle, and a reduced obstruction angle. The high visibility torch includes consumables adapted to maintain torch and consumables performance while reducing visual obstruction to the user, by coordinating, balancing, and optimizing design requirements and stack up tolerances. The invention also includes a related low-profile safety switch that promotes workpiece visibility and minimizes view obstruction.

Abstract: A method and device for controlling a power source of a welding, cutting or plasma coating system is provided. The power source comprises a measuring part and a controllable clocked power part. A value correlating with a characteristic variable of the power part to be controlled is continuously measured by means of the measuring part, to obtain an electrical measured variable. The electrical measured variable is at least approximately integrated starting from a prescribed initial value over a prescribed integration time, the duration of which corresponds to one or more clock periods of the clocked power part. A measure value is continuously determined from the integration value and used to control the power part.

Abstract: A plasma supply device generates an output power greater than 500 W at an essentially constant basic frequency greater than 3 MHz and powers a plasma process to which is supplied the generated output power, and from which reflected power is returned to the plasma supply device. The plasma supply device includes at least one inverter connected to a DC power supply, which inverter has at least one switching element, and an output network. The output network is arranged on a printed circuit board. The output network can therefore be designed low priced and accurately.

Abstract: An electrode for a contact start plasma arc torch includes an elongated electrode body formed of an electrically conductive material. The electrode body is movable relative to the torch. A resilient element is used for passing substantially all of a pilot arc current between a power supply, a power connection in electrical communication with the power supply, and the electrode body during pilot arc operation of the plasma arc torch. The electrode and torch can include a contact element having a first surface in electrical communication with the power contact and a second surface for physical contact and electrical communication with a corresponding contact surface of the electrode body for passing substantially all of a transferred arc current between the power supply and the electrode body during transferred arc mode.

Abstract: A method of stably controlling the temperature of a sample placed on a sample stage to a desired temperature by estimating a sample temperature accurately, the sample stage including a refrigerant flow path to cool the sample stage, a heater to heat the sample stage, and a temperature sensor to measure the temperature of the sample stage. This method comprises the steps of: measuring in advance the variation-with-time of supply electric power to the heater, temperature of the sample, and temperature of the temperature sensor, without plasma processing; approximating the relation among the measured values using a simultaneous linear differential equation; estimating a sample temperature from the variation-with-time of sensor temperature y1, heater electric power u1, and plasma heat input by means of the Luenberger's states observer based on the simultaneous linear differential equation used for the approximation; and performing a feedback control of sample temperature using the estimated sample temperature.

Abstract: The present invention relates to a heat treatment apparatus that performs activation annealing or defect repair annealing and surface oxidization which succeed impurity doping intended to control the conductive property of a semiconductor substrate. In the present invention, a sample to be heated is placed on a lower electrode in a plasma treatment chamber. A gap between an upper electrode and the lower electrode is filled with a gap whose main raw material is a rare gas (helium, argon, krypton, xenon, or the like) having a pressure close to the atmospheric pressure. A power fed from a high-frequency power supply is applied to the upper electrode in order to induce an atmospheric-pressure glow discharge. Gas heating in the gap between the electrodes, which depends on the glow discharge, is used to heat-treat the sample to be heated.

Abstract: A recirculation system of a substrate support on which a semiconductor substrate is subjected to a multistep process in a vacuum chamber, the system comprising a substrate support having at least one liquid flow passage in a base plate thereof, an inlet and an outlet in fluid communication with the flow passage, a supply line in fluid communication with the inlet, and a return line in fluid communication with the outlet; a first recirculator providing liquid at temperature T1 in fluid communication with the supply line and the return line; a second recirculator providing liquid at temperature T2 in fluid communication with the supply line and the return line, temperature T2 being at least 10° C. above temperature T1; a pre-cooling unit providing liquid at temperature Tpc connected to the inlet and the outlet, temperature Tpc being at least 10° C. below T1; a pre-heating unit providing liquid at temperature Tph connected to the inlet and the outlet, temperature Tph being at least 10° C.

Abstract: An electrical pulse circuit is disclosed. The electrical pulse circuit is in connection with a first pair of electrodes defining a first gap between ends thereof and a second pair of electrodes defining a second gap between ends thereof. The second gap is disposed proximate to the first gap. The circuit includes a controller, a first electrical pulse source in power connection with the first pair of electrodes, and a second electrical pulse source in power connection with the second pair of electrodes. The first electrical pulse source is productive of a high voltage low current arc across the first gap in response to the controller and the second electrical pulse source is productive of a low voltage high current arc across the second gap in response to the controller and the high voltage arc.

Abstract: A variable arc gap plasma igniter element includes electrodes moveable relative to each other. The electrodes are preferably set to define a smaller air gap to initiate a plasma arc and later extended to obtain longer plasma arc.

Abstract: A sensor apparatus for measuring a plasma process parameter for processing a workpiece. The sensor apparatus includes a base, an information processor supported on or in the base, and at least one sensor supported on or in the base. The at least one sensor includes at least one sensing element configured for measuring an electrical property of a plasma and may include a transducer coupled to the at least one sensing element. The transducer can be configured to receive a signal from the sensing element and convert the signal into a second signal for input to the information processor.

Abstract: A plasma cutting device performs cutting in a plurality of stages. In a first cutting sub-process, a manufactured product is cut out from a base material upon a stage according to an NC program. Next, images of respective regions in the vicinities of proper positions at two corner points of the manufactured product which has been cut out are photographed by an image sensor, the actual positions of these two corner points of the manufactured product are detected from these images which have been photographed, and the translation distances and the rotational angle between the actual positions which have been detected and the proper positions are calculated. The NC program is corrected. And, in a subsequent cutting sub-process, additional cutting for beveling is carried out upon cutting surfaces at the outer circumference of the manufactured product, according to the corrected NC program.

Abstract: A system for the data management of a thermal spraying apparatus with a spray gun (2) is made available, wherein the system includes a decentrally arranged device (1) with a memory (4), in order to detect process parameters and to store data of the thermal spraying apparatus and wherein the data contain identification and operating data of the thermal spraying apparatus and the device (1) additionally includes a bus interface (6) for the transmitting of the data.

Abstract: An improved torch providing high visibility of the work zone to the operator, an increased viewing angle, and a reduced obstruction angle. The high visibility torch includes consumables adapted to maintain torch and consumables performance while reducing visual obstruction to the user, by coordinating, balancing, and optimizing design requirements and stack up tolerances. The invention also includes a related low-profile safety switch that promotes workpiece visibility and minimizes view obstruction.

Abstract: Generating drive signals of at least two RF power generators which supply RF power to a plasma process, in which at least two drive signals, each driving one RF power generator, are generated in an RF generator driver. Each drive signal is generated by a respective function generator, such as a digital sine generator, of the generator driver.

Abstract: A starting circuit for use with a plasma torch is provided including circuitry for initiating a pilot arc using a unipolar voltage impulse. A transformer is selectively coupled to a DC source so that an impulse is introduced using the same DC source used to maintain an established pilot arc. A method is provided wherein an arc can be initiated while at the same time the DC source is pre-loaded so that surge injection circuitry is not needed to sustain the arc while ramping to the full pilot arc current level.

Abstract: A universal power supply for use in a plasma arc system is disclosed. The power supply can include a plurality of power modules for providing a DC output from an AC input. Each of the power modules can include a rectifier, a converter, an inverter, an isolation transformer and an output rectifier. The power modules can include a power module controller configured to control at least one of the rectifier, the converter, or the inverter such that a DC output can be obtained from a wide variety of AC inputs. The power modules can be connected in parallel to provide a wide range of DC output currents for the power supply. The universal power supply can include a master controller coupled to each of the individual power module controllers to regulate the DC output current of the power supply by controlling the individual power module controllers.

Abstract: A sensor apparatus for measuring a plasma process parameter for processing a workpiece. The sensor apparatus includes a base, an information processor supported on or in the base, and at least one sensor supported on or in the base. The at least one sensor includes at least one sensing element configured for measuring an electrical property of a plasma and at least one transducer coupled to the at least one sensing element. The transducer is configured so as to receive a signal from the sensing element and converting the signal into a second signal for input to the information processor.

Abstract: A plasma source with discharge inducing bridges and a plasma processing system using the same. The plasma source may be constructed with a number of discharge inducing bridges, each discharge inducing bridge containing a magnetic core with a primary winding of a transformer. The discharge inducing bridges are positioned so as to face a susceptor. Each discharge inducing bridge is a hollow tube. When the electrical current of the primary winding of the transformer is driven, magnetic flux is induced to the magnetic core, so that inductive coupled plasma is formed around the discharge inducing bridges, and a plasma discharge is evenly induced horizontally/vertically along the discharge inducing bridges, so that uniform large-area high-density plasma is generated.

Abstract: A device for producing a gas plasma by ionisation of a gas using a microwave source of determined nominal power (Pn), includes a magnetron 7 receiving its electric energy from a supply circuit. The device is characterized in that the power (Pd) delivered by the supply circuit to the magnetron 7 is no more than one quarter of the nominal power (Pn) of the magnetron 7.

Abstract: The invention relates to a method and a circuit for igniting a gas flow in a fully automatic manner. The aim of the invention is to maintain the necessary current consumption so low that an integratable voltage source can be used. To this end, once an electronic control unit has been activated, a thermoelectric safety pilot valve (2) is opened by an electromagnet which is temporarily excited by a rush of current, is maintained in the open position by a safety pilot magnet (6) by means of a holding current provided by a voltage source (10), and the escaping gas is ignited. Once a thermoelectric couple (4) is provided for the necessary holding current, the voltage source (10) is switched off. In the event of damage, the method is automatically interrupted.

Abstract: An arc detector is provided for a plasma processing system including a HF power source, a plasma processor, and a voltage/current signal detector. The arc detector includes a calculator for the phase difference between the AC voltage signal and the AC current signal, a calculator for an effective voltage based on the AC voltage signal, a calculator for an effective current based on the AC current signal, an FFT processor for the frequency spectrum of the AC voltage or current signal, and an arc analyzer connected to the phase difference calculator, effective voltage calculator, effective current calculator, and FFT processor. The arc analyzer calculates the plasma processor's impedance based on the calculated phase difference, effective voltage, and effective current. The arc analyzer monitors arcs in the plasma processor, based on the fluctuation rate of the calculated impedance and the output level of a frequency component in the spectrum.

Abstract: A method and apparatus for controlling power output of a capacitatively-coupled plasma are provided. A detector is disposed on the power delivery conduit carrying power to one electrode to detect fluctuations in power output to the electrode. The detector is coupled to a signal generator, which converts the RF input signal to a constant control signal. A controller adjusts power input to the RF generator by comparing the control signal to a reference.

Abstract: A plasma arc torch is provided that includes a wear stop designed to detect wear of an electrode and prevent the use of the electrode once the electrode has experienced a certain amount of wear. Either the electrode or the nozzle is movable with respect to the main torch body, and the movable component defines a projection. The wear stop is positioned a predetermined distance from a nozzle of the torch, such that prior to experiencing an excessive amount of wear, the electrode is able to contact the nozzle and initiate a pilot arc for starting a torch operation. Once the length of the electrode becomes shorter than a predetermined length due to wear, the projection of the electrode engages the wear stop, and the wear stop prevents the electrode from contacting the nozzle. In this way, an electrode that is excessively worn cannot be used in subsequent torch operations.

Abstract: In one implementation, a method is provided for testing a plasma reactor multi-frequency matching network comprised of multiple matching networks, each of the multiple matching networks having an associated RF power source and being tunable within a tunespace. The method includes providing a multi-frequency dynamic dummy load having a frequency response within the tunespace of each of the multiple matching networks at an operating frequency of its associated RF power source. The method further includes characterizing a performance of the multi-frequency matching network based on a response of the multi-frequency matching network while simultaneously operating at multiple frequencies.

Abstract: A system for conserving a consumable component of a plasma torch is disclosed. The system includes a controller of a plasma torch that is connected to a power source. The controller is configured to, during a single trigger actuation, delay generation of an arc after a prior arc collapses. Such a control allows the consumable components of the plasma torch to cool prior to subsequent operation.

Abstract: A plasma processing apparatus performs plasma processing on a processing target in a processing chamber. The apparatus includes: an object to be heated provided near a periphery of a mounting table disposed in the processing chamber; and a heating electrode disposed adjacent to the periphery of the mounting table, for heating the object to be heated. A first coil having a first path and a second coil having a second path are wired close to each other in the heating electrode along the periphery of the mounting table.

Abstract: A system for the efficient utilization of plasma torch post arc cooling gas includes a controller configured to automatically determine a post arc gas flow duration. The controller monitors a plasma arc parameter associated with a temperature of the plasma torch at arc termination. The controller dynamically determines the duration of post arc gas flow through the torch from the plasma arc parameter.

Abstract: Inductively coupled plasma (ICP) reforming converts carbonaceous compounds into a fuel for use in generating electrical power. Energy rich hydrocarbon fuels, such as coal, marine diesel, oils, and hydrocarbon wastes are employed as a feedstock for the ICP, which transforms the feedstock into a fuel that can be used by fuel cells and gas turbines for the production of electricity. The overall efficiency of an ICP-based electrical power system can be increased by providing partial oxidation within the reaction vessel. The partial oxidation conditions consume a small amount of the reformed fuel gas, thereby liberating sufficient thermal energy to reduce the electrical power requirements of the ICP to maintain desired reactor temperatures, and providing an increase in the overall net electrical power production. The integrated power production system can also adjust to meet an increased requirement for process heat and steam by balancing the effect of partial oxidation.

Abstract: An RF blocking filter isolates a two-phase AC power supply from at least 2 kV p-p of power of an HF frequency that is reactively coupled to a resistive heating element, while conducting several kW of 60 Hz AC power from the two-phase AC power supply to the resistive heating element without overheating, the two-phase AC power supply having a pair of terminals and the resistive heating element having a pair of terminals. The filter includes a pair of cylindrical non-conductive envelopes each having an interior diameter between about one and two inches and respective pluralities of fused iron powder toroids of magnetic permeability on the order of about 10 stacked coaxially within respective ones of the pair of cylindrical envelopes, the exterior diameter of the toroids being about the same as the interior diameter of each of the envelopes. A pair of wire conductors of diameter between 3 mm and 3.

Abstract: A system and method for managing power delivered to a processing chamber is described. In one embodiment current is drawn away from the plasma processing chamber while initiating an application of power to the plasma processing chamber during an initial period of time, the amount of current being drawn away decreasing during the initial period of time so as to increase the amount of power applied to the plasma processing chamber during the initial period of time.

Abstract: An etching method and an etching system are adapted to produce a high etch selectivity for a mask, an excellent anisotropic profile and a large etching depth. An etching system according to the invention comprises a floating electrode arranged vis-à-vis a substrate electrode in a vacuum chamber and held in a floating state in terms of electric potential, a material arranged at the side of the floating electrode facing the substrate electrode to form an anti-etching film and a control unit for intermittently applying high frequency power to the floating electrode.

Abstract: A method and apparatus for producing soft x-ray laser radiation. A low pressure plasma column is created by electric discharge or by laser excitation inside a rotating containment tube. Rotation of the plasma is induced by viscous drag caused by rotation of the tube, or by magnetically driven rotation of the plasma as it is created in a plasma gun in the presence of an axial magnetic field, or both. A high power electrical discharge is then passed axially through the rotating plasma column to produce a rapidly rising axial current, resulting in z-pinch compression of the rotating plasma column, with resultant stimulated emission of soft x-ray radiation in the axial direction. A rotating containment tube used in combination with magnetically driven rotation of the plasma column results in a concave electron density profile that results in reduced wall ablation and also reduced refraction losses of the soft x-rays.

Abstract: The invention relates to a device for machining, particularly for cutting, of electrically conductive workpieces using a machining tool (10), which can be displaced back and forth toward and away from a workpiece by means of a drive unit and which comprises an electrically insulated, metallic tool head (12) forming a first capacitance (C1) with the workpiece, and comprising an analysis unit (14) for analyzing a characteristic value dependent on the first capacitance (C1) . The invention provides that a metallic connecting element (18) is attached to the tool head (12), the element being connected to the analysis unit (14) and forming a second capacitance (C2) with the tool head (12).

Abstract: Embodiments of field enhanced inductively coupled plasma reactors and methods of use of same are provided herein. In some embodiments, a field enhanced inductively coupled plasma processing system may include a process chamber having a dielectric lid and a plasma source assembly disposed above the dielectric lid. The plasma source assembly includes one or more coils configured to inductively couple RF energy into the process chamber to form and maintain a plasma therein, one or more electrodes configured to capacitively couple RF energy into the process chamber to form the plasma therein, wherein the one or more electrodes are electrically coupled to one of the one or more coils, and an RF generator coupled to the one or more inductive coils and the one or more electrodes. In some embodiments, a heater element may be disposed between the dielectric lid and the plasma source assembly.

Abstract: A method processing a workpiece in a plasma reactor chamber in which a first one of plural applied RF plasma powers is modulated in accordance with a time-varying modulation control signal corresponding to a desired process transient cycle. The method achieves a reduction in reflected power by modulating a second one of the plural plasma powers in response to the time-varying modulation control signal.

Abstract: A contact start plasma system is provided that includes a passive pilot arc circuit that decreases the size and cost of the system. The plasma arc system includes a torch body, an electrode having a longitudinally disposed axis and mounted in the body, a nozzle having a longitudinally disposed axis, the nozzle axis being disposed substantially collinearly with the electrode axis, a power supply coupled to the electrode, the nozzle and a workpiece, the power supply providing a current for operating the torch in a pilot arc mode and a transferred arc mode, a gas source coupled to the plasma chamber, the gas source providing gas for operating in a pilot arc mode and a transferred arc mode, and a passive pilot arc circuit coupled between the power supply and the nozzle, the passive pilot arc circuit controlling the operation of the torch in the pilot arc mode. Either the electrode or the nozzle can be translatable for blow-forward or blow-back mode of operation.