Abstract: In some aspects, nozzles for a gas-cooled plasma torches can include a hollow generally cylindrical body having a first end and a second end that define a longitudinal axis, the second end of the body defining a nozzle exit orifice; a gas channel formed in the first end between an interior wall and an exterior wall of the cylindrical body, the gas channel directing a gas flow circumferentially about at least a portion of the body; an inlet passage formed substantially through a radial surface of the exterior wall and fluidly connected to the gas channel; and an outlet passage at least substantially aligned with the longitudinal axis and fluidly connected to the gas channel.

Abstract: A nozzle for a liquid cooled plasma torch includes a nozzle bore for the exit of a plasma gas beam at a nozzle tip, a first section, of which the outer surface is essentially cylindrical, and a second section connecting the nozzle tip, of which the second section the outer surface tapers essentially conically towards the nozzle tip, wherein at least one liquid supply groove is provided and extends over a part of the first section and over the second section in the outer surface of the nozzle towards the nozzle tip and at least one liquid return groove separate from the liquid supply groove is provided and extends over the second section.

Abstract: Plume shield shroud (10) for a plasma gun (30) includes a substantially tubular member (14) comprising an axial length, a plume entry end (11), and a plume exit end (13). The shroud (10) is adapted to be mounted to a plasma gun (30). A method of protecting, confining or shielding of a gas plume of a plasma gun (30) includes mounting (20) a gas plume shroud (10) on the plasma gun (30) such that the shroud (10) is sized and configured to substantially surround at least a portion of the gas plume.

Abstract: An electrode for a plasma arc torch includes a generally cylindrical elongated body formed of an electrically conductive material. The elongated body includes a proximal end that connects to a power supply and a distal end that receives an emissive element. The electrode can include a flange that is disposed about a surface relative to the distal end of the elongated body, extends radially from the surface of the elongated body, and is utilized to establish a uniform gas flow distribution of a plasma gas flow about the distal end of the elongated body. The electrode can include a contact element that is in electrical communication with the proximal end of the electrode. The contact element includes seating portion that has an outer width that is greater than the outermost diameter of the electrode body and is configured to position the contact element within the plasma arc torch.

Abstract: A torch tip for a plasma arc torch includes a body having a first end, configured to attach to the torch, and a second end, where an end wall is disposed. A plasma exit orifice is formed in the end wall. At least two castellations are formed in the end wall. Each castellation has a castellation width defined by the distance between the sidewalls of that castellation. At least one slot is disposed between two castellations. Each slot has a slot width defined by a distance between the sidewalls of its adjacent castellations. The slot width can be at least twice the castellation width. Each slot also has a slot floor and an exterior shape. The slot floor can have slope that tapers toward the first end of the body in an outward radial direction and the exterior shape of the slot can have a generally V-shaped or U-shaped contour.

Abstract: A method of operating a plasma arc torch is provided that includes directing a first portion of gas into a plasma chamber, directing a second portion of the gas to initiate a pilot arc in the plasma chamber, and redirecting the second portion of the gas to form a shield gas flow rather than venting the second portion to atmosphere. A plasma arc torch for this method includes a start cartridge disposed between an electrode and a tip for initiating the pilot arc. The start cartridge defines at least one redirect gas passageway in fluid communication with a shield gas passageway. The second portion of gas is redirected through the at least one redirect gas passageway and into the shield gas passageway.

Abstract: A nozzle protection cap for an arc plasma torch comprises a front end section and a rear end section with a thread region on its inner surface for screwing to a torch body of an arc plasma torch. At least one groove crosses the thread region on the inner surface. A nozzle protection cap holder for the arc plasma torch comprises a section with a thread region on its outer surface for screwing to the nozzle protection cap. At least one groove crosses the thread region on its outer surface. An arc plasma torch comprises a torch body and a nozzle protection cap screwed thereto in a screw connection region. The torch body and/or the nozzle protection cap is/are designed so that at least one channel is formed between them, the channel crossing the screw connection region.

Abstract: A metal jet apparatus comprises a discharge nozzle 31 for jetting molten metal 20, and a gas passage 33 for supplying inert gas to a peripheral portion of a discharge port 32 of the discharge nozzle 31. The discharge port 32 of the discharge nozzle 31 and an outlet of a gas passage 33 are provided with a nozzle cover 34. The nozzle cover 34 includes a space 35 which is in communication with the discharge port 32 and the outlet of the gas passage 33, and which opens downward. A ring-like projection 36 is disposed around the opening. When the molten metal 20 is jetted from the discharge port 32 into the space 35, the inert gas is supplied to the space 35, thereby preventing the molten metal 20 from being oxidized, and it is possible to prevent the nozzle of the discharge port 32 from being clogged, and to form the molten metal 20 into a spherical shape.

Abstract: The present invention relates to an apparatus for adjusting a position of a plasma arc torch. The apparatus includes an elevation apparatus configured to raise and lower the plasma arc torch with respect to molten silicon, a rotary apparatus configured to circumferentially rotate the plasma arc torch with respect to the molten silicon, and an angle adjustment apparatus configured to adjust an angle of the plasma arc torch with respect to the molten silicon. In addition, a plurality of plasma arc torches is provided and radially disposed at predetermined intervals. Therefore, time consumed to melt solid silicon to form the initial molten silicon is reduced, and casting speed is increased. In addition, fusibility of a source material can be improved, the source material can be stably melted, and economic continuous casting and a high quality silicon ingot for a solar cell can be manufactured.

Abstract: A plasma torch is provided having an electrode with a frustoconical end portion. The electrode is received by a plunger during a contact start sequence of the plasma torch and is self-releasing from the torch. The electrode may include a shoulder portion that provides concentric alignment and centering of the electrode with respect to the central longitudinal axis of the components. Other components of the torch include a nozzle, a swirl ring, and retaining cup, such that the consumables of the torch may be toollessly removed and installed.

Abstract: A device to provide improved anti-smudging, better gripping and longer shelf-life to products and surfaces includes an electric superheated steam generator and an electric low-ion plasma generator to provide superheated steam and low-ion plasma to the surfaces of products including plastics. One embodiment envisions the superheated steam generator and the low-ion plasma generator being contained in a housing while another embodiment anticipates a conveyor means positioned in front of the superheated steam generator and the low-ion plasma generator. A method for the improving of anti-smudging, gripping and shelf-life for properties includes the application of superheated steam and low-ion plasma by means of a superheated steam generator and a low-ion plasma generator to products for specific periods of time and at specific distances to attain desired surface and bulk properties. The superheated steam and low-ion plasma may be applied individually, simultaneously or sequentially.

Abstract: A nozzle for a plasma arc torch includes a body having a first end and a second end. The nozzle also includes a plasma exit orifice located at the first end of the body. A flange is located at the second end of the body. The flange is adapted to mate with a corresponding consumable. The flange is configured to selectively block at least one gas passage in the corresponding consumable to establish a gas flow relative to the nozzle body.

Abstract: Adhesion and accumulation of spatter onto a covering member that encloses the outer periphery of a torch is minimized and flying of spatter is confined within a narrow area. To this end, a covering member for enclosing a specified angular range of the outer periphery of a plasma torch 9 is provided and an opening portion 35 is formed between every adjacent shielding plates 34 in the covering member.

Abstract: A nozzle for a liquid-cooled plasma torch, comprising a nozzle bore for the exit of a plasma gas jet at a nozzle tip, a first portion, the outer surface of which is substantially cylindrical, and a second portion adjacent thereto towards the nozzle tip, the outer surface of which tapers substantially conically towards the nozzle tip, wherein at least one liquid supply groove and/or at least one liquid return groove is/are provided and extend over the second portion in the outer surface of the nozzle (4) towards the nozzle tip, and wherein the liquid supply groove or at least one of the liquid supply grooves and/or a liquid return groove or at least one of the liquid return grooves also extends/extend over part of the first portion, and there is in the first portion at least one groove which communicates with the liquid supply groove or at least one of the liquid supply grooves or with the liquid return groove or at least one of the liquid return grooves.

Abstract: The invention relates to a device generating a plasma flow comprising an electrically conductive housing, tubular in shape, forming a central channel traversed by a vortex gas, a central electrode arranged coaxially in said channel and an electric power source intended to apply an electric voltage V between the electrode and the housing, characterized in that the mean diameter of the channel formed by the housing decreases progressively from an area situated substantially at the level of the free end of the electrode as far as an end area of said housing, said end area being configured in such a way that the minimum electric voltage Vcmin(0) to be applied in order to develop an electric arc between said electrode and said end area is strictly greater than said voltage V.

Abstract: A consumable set is provided that is usable in a plasma arc torch to direct a plasma arc to a processing surface of a workpiece. The consumable set comprises a nozzle and an alignment surface. The nozzle includes: 1) a nozzle body defining a longitudinal axis extending therethrough, and 2) a nozzle exit orifice disposed in the nozzle body for constricting the plasma arc. The nozzle exit orifice defines an exit orifice axis oriented at a non-zero bevel angle relative to the longitudinal axis. The alignment surface is generally parallel to the longitudinal axis and substantially planar. The alignment surface is dimensioned to orient the nozzle exit orifice such that the plasma arc impinges on the processing surface of the workpiece at the bevel angle while the plasma arc torch is substantially perpendicular to the processing surface.

Abstract: A torch tip for a plasma arc torch includes a body having a first end, configured to attach to the torch, and a second end, where an end wall is disposed. A plasma exit orifice is formed in the end wall. At least two castellations are formed in the end wall. At least one slot is disposed between two castellations. Each slot is defined by a first and second castellation wall, and a slot floor. The first castellation wall is opposite the second castellation wall. The torch tip has at least one of the following characteristics: a slope of the slot floor within the at least one slot tapers in an outward radial direction relative to the plasma exit orifice toward the first end of the body, or a distance between the first and second castellation walls along the slot floor increases with distance away from the exit orifice.

Abstract: A nozzle, retaining cap, or shield for a plasma arc torch that includes a surface defining a conductive contact portion for exchanging heat with an adjacent torch component. The adjacent torch component can be a retaining cap, electrode or nozzle. The surface of the nozzle, retaining cap, or shield can also at least partially define a cooling channel having a curvilinear surface. A sealant portion can be positioned between the conductive contact portion and the cooling channel. The sealant portion can form or create a fluid barrier between the cooling channel and the conductive portion.

Abstract: A laser ablation system includes a sample chamber 102 configured to accommodate a target 104 within an interior 106 thereof, a sample generator 108 configured to remove a portion of the target 104 (which may be subsequently captured as a sample) and an analysis system 110 configured to analyze a composition of the sample. A sample capture cell in the chamber proximate to the target has a capture cavity configured to receive target material, a first inlet configured to transmit a flow of a carrier gas from a first location adjacent to an exterior of the capture cell into a region of the capture cavity; and an outlet configured to receive carrier gas from another region of the capture cavity. The sample chamber 102 includes an injection nozzle 120 configured to introduce, into the interior 106, a fluid such as a carrier gas.

Abstract: A plasma gun system comprising: a plasma gun comprising an outlet, wherein the plasma gun is configured to generate a plasma stream and provide the plasma stream to the outlet; and a plasma gun extension assembly configured to be coupled to the plasma gun, wherein the plasma gun extension assembly comprises an extension chamber and a port, the extension chamber having an interior diameter defined by a chamber wall and being configured to receive the plasma stream from the outlet of the plasma gun and to enable the plasma stream to expand upon entering the extension chamber, and the port being configured to introduce a powder to the expanded plasma stream at a location outside of the plasma gun.

Abstract: A plasma arc torch includes an annular baffle defining distinct faces A, B, C, and D. Faces A and C are opposite from each other, and faces B and D are opposite from each other. First passages for fluid flow extend between the faces A and C, and second passages extend between the faces B and D. The baffle is installable in an annular space between an inner wall and an outer wall, in either of two orientations. In a first orientation, the first passages are open to fluid flow and the second passages are closed by engagement of the inner and outer walls with the faces B and D, and in a second orientation, flipped over relative to the first orientation, the second passages are open to fluid flow and the first passages are closed by engagement of the inner and outer walls with the faces A and C.

Abstract: A plasma treatment system includes a plasma arc torch, a tee attached to a hollow electrode nozzle of the plasma arc torch, and a screw feed unit or a ram feed unit having an inlet and an outlet attached to the tee. The plasma arc torch includes a cylindrical vessel having a first end and a second end, a first tangential inlet/outlet connected to or proximate to the first end, a second tangential inlet/outlet connected to or proximate to the second end, an electrode housing connected to the first end of the cylindrical vessel such that a first electrode is (a) aligned with a longitudinal axis of the cylindrical vessel, and (b) extends into the cylindrical vessel, and a hollow electrode nozzle connected to the second end of the cylindrical vessel such that a centerline of the hollow electrode nozzle is aligned with the longitudinal axis of the cylindrical vessel.

Abstract: A nozzle or retaining cap for a plasma arc torch that includes a surface defining a conductive contact portion for exchanging heat with an adjacent torch component. The adjacent torch component can be a retaining cap, electrode or nozzle. The surface of the nozzle or retaining cap can also at least partially define a cooling channel having a curvilinear surface. A sealant portion can be positioned between the conductive contact portion and the cooling channel. The sealant portion can form or create a fluid barrier between the cooling channel and the conductive portion.

Abstract: An improved electrode for use in a plasma arc torch. The electrode includes an electrode body, a cavity in a front face at a first end of the electrode body, and an insert disposed in the cavity. The first end of the electrode body is formed of high purity copper containing at least 99.81% copper. The insert has a first end and a second end and is formed of a high emissivity material. A diameter of the first end of the insert is less than a diameter of a second end of the insert. An electrode is compressed to retain the insert using radial compression. The invention also includes a method for forming the electrode, and a method of operation of an electrode in a plasma torch.

Abstract: A system, method and apparatus for recovering mining fluids from mining byproducts uses a plasma arc torch and a screw feed unit. The plasma arc torch includes a cylindrical vessel, a first tangential inlet/outlet connected to or proximate to a first end, a second tangential inlet/outlet connected to or proximate to a second end, an electrode housing connected to the first end such that a first electrode is (a) aligned with a longitudinal axis of the cylindrical vessel, and (b) extends into the cylindrical vessel, and a hollow electrode nozzle is connected to the second end such that the hollow electrode nozzle is aligned with the longitudinal axis, the hollow electrode nozzle is partially disposed within the cylindrical vessel and outside the cylindrical vessel. The screw feed unit has an inlet and an outlet, the outlet aligned with the centerline and proximate to the hollow electrode nozzle.

Abstract: A steam plasma torch includes a anode in the form of a nozzle, a first body for receiving the anode, a flow swirler mounted between the anode and the rod type cathode for inducing vorticity into working gas flow, an insulator connected to the first body, a second body connected to the insulator and formed with a thread, an adjusting element formed with a thread engaged with the thread of the second body, a collet fit in the adjusting element and a cathode in the form of a rod fit in the collet. A gap between the anode and cathode is adjusted when the adjusting element is rotated relative to the second body.

Abstract: In some aspects, a plasma processing torch can include an end portion that receives at least one gas and at least one power input; a first joint coupled to the end portion, the first joint conveying the gas and power through the first joint; a middle portion coupled to the first joint, the middle portion conveying the gas and power through the middle portion; a second joint coupled to the middle portion at an end opposite the first joint, the pivot joint conveying the gas and power through the pivot joint; and a head portion coupled to the second joint, the head portion conveying the gas and power to a torch tip to generate a plasma arc.

Abstract: In some aspects, nozzles for plasma torches can include a nozzle body having a proximal end and a distal end that define a nozzle body length and a longitudinal axis. The body can include an exit orifice defined by the distal end; a plenum extending from the proximal end to a plenum floor, a distance from the plenum floor to the distal end defining a plenum floor thickness, and a distance from the plenum floor to the proximal end defining a proximal end height; and a bore extending from the plenum floor to the exit orifice that has a bore length and a bore width. The nozzle body has a nozzle width in a direction transverse to the longitudinal axis. The nozzle body length is greater than the width and a ratio of the proximal end height to the plenum floor thickness is less than 2.0.

Abstract: A shield device for a plasma arc torch includes an inner shield member defining an inner auxiliary gas chamber and an outer shield member surrounding the inner shield member. An outer auxiliary gas chamber is defined between the inner shield member and outer shield member. The shield device allows an auxiliary gas flow to be split into a first flow of auxiliary gas through the inner auxiliary gas chamber and a second flow of auxiliary gas through the outer auxiliary gas chamber. The inner shield member and the outer shield member are configured to be mounted to the plasma arc torch as an integral unit.

Abstract: Internal coarse particle injection plasma transferred arc torch nozzles comprising: a heat-resistant nozzle body; at least one coarse hard-metal particle internal injection port; at least one fine hard-metal particle and matrix internal injection port; at least one gas port; and a cathode. Related systems, apparatus, compositions, and methods involving such arc torch nozzles are also disclosed.

Abstract: A process for plasma treating a substrate comprises applying a radio frequency high voltage to at least one electrode positioned within a dielectric housing having an inlet and an outlet while causing a process gas, usually comprising helium, to flow from the inlet past the electrode to the outlet, thereby generating a non-equilibrium atmospheric pressure plasma. An atomised or gaseous surface treatment agent is incorporated in the non-equilibrium atmospheric pressure plasma. The substrate is positioned adjacent to the plasma outlet so that the surface is in contact with the plasma and is moved relative to the plasma outlet. The velocity of the process gas flowing past the electrode is less than 100 m/s. Process gas is also injected into the dielectric housing at a velocity greater than 100 m/s. The volume ratio of process gas injected at a velocity greater than 100 m/s to process gas flowing past the electrode at less than 100 m/s is from 1:20 to 5:1.

Abstract: A consumable set is provided that is usable in a plasma arc torch to direct a plasma arc to a processing surface of a workpiece. The consumable set includes a nozzle having: 1) a nozzle body defining a longitudinal axis extending therethrough, and 2) a nozzle exit orifice, disposed in the nozzle body, for constricting the plasma arc. The nozzle exit orifice defines an exit orifice axis oriented at a non-zero angle relative to the longitudinal axis. The consumable set can also include an alignment surface generally parallel to the exit orifice axis. The alignment surface is dimensioned to align the exit orifice such that the plasma arc impinges orthogonally on the processing surface.

Abstract: A cathode electrode for plasma generation. The cathode is made of graphite with highly ordered structure such as Pyrolitic Graphite or Carbon-Carbon composites. Furthermore, carbon containing gases will be used as plasma gas. The cathode will allow for theoretically an unlimited lifetime of the cathode.

Abstract: A nozzle for use in a plasma arc torch is provided. The nozzle includes an aft portion comprising a conductive first material with a first density. The aft portion defines a proximal end and a distal end. The nozzle includes a substantially hollow forward portion including 1) a tip section comprising a conductive second material with a second density, and 2) a rear section configured to couple the forward portion to the proximal end of the aft portion. The second density is at least two times greater than the first density. The nozzle further includes a plasma exit orifice disposed in the tip section of the forward portion.

Abstract: Certain embodiments described herein are directed to a torch that includes a suitable amount of a refractory material. In some embodiments, the torch can include one or more non-refractory materials in combination with a refractory material. In some embodiments, the torch can comprise a refractory material and an optically transparent window. In other embodiments, the torch can comprise a material comprising a melting point higher than the melting point of quartz.

Abstract: An electrode is provided for use in a plasma arc torch. The electrode includes a body having a forward portion, a middle portion and an aft portion. The forward portion includes an electrode tip comprising a conductive first material, wherein the electrode tip includes: 1) a pilot contact region for initiating a pilot arc across the nozzle and 2) an emitter. The middle portion comprises a second material and defines a proximal end for mating with the forward portion and a distal end for mating with the aft portion. The material density of the second material is at least half of the material density of the first material. The electrode also includes an electrically conductive path extending from the forward portion to the aft portion of the body.

Abstract: A plasma arc torch includes an annular baffle defining distinct faces A, B, C, and D. Faces A and C are opposite from each other, and faces B and D are opposite from each other. First passages for fluid flow extend between the faces A and C, and second passages extend between the faces B and D. The baffle is installable in an annular space between an inner wall and an outer wall, in either of two orientations. In a first orientation, the first passages are open to fluid flow and the second passages are closed by engagement of the inner and outer walls with the faces B and D, and in a second orientation, flipped over relative to the first orientation, the second passages are open to fluid flow and the first passages are closed by engagement of the inner and outer walls with the faces A and C.

Abstract: The invention relates to a liquid-cooled plasma burner, comprising a nozzle bore for the plasma gas jet to exit at a nozzle tip and a first section whose outer surface gradually tapers in the shape of a cone at an angle ? in the direction of the nozzle tip, except for at least one deflection section that extends in the shape of a cone at an angle ? in the direction of the nozzle tip. The invention also relates to an arrangement thereof with a nozzle cap and to a plasma burner comprising such an arrangement.

Abstract: A plasma arc torch both cutting and marking of metal workpieces includes a plasma nozzle having a plasma nozzle orifice through which an electric arc from an electrode and a stream of plasma gas are emitted toward a workpiece, and a liquid-injection shield cup that injects liquid tangentially inwardly to the arc and stream of plasma gas. A power supply is operable to selectively deliver electrical power to the electrode at either a low power level suitable for marking of a workpiece or a high power level suitable for workpiece cutting. The torch may be selectively operated to mark at the low power level, with a plasma marking gas being delivered to the plasma gas passage, or to cut at the high power level, with a plasma cutting gas being delivered to the plasma gas passage, and liquid being delivered to the liquid injection passage for both cutting and marking.

Abstract: A DC steam plasma torch includes front, middle and rear sections. The front section includes a first amount and a first electrode attached to the first amount, thus defining co-axial first internal and external coolant channels. The middle section includes a second mount and a second electrode co-axially connected to the second mount, thus defining co-axial second internal and external coolant channels. The rear section includes an insulating transient element connected to the second electrode, a window frame connected to the insulating transient element and a window provided in the window frame. A first swirl generator is provided between the first and second sections to receive primary working gas and generating a swirl in the same. A second swirl generator is provided between the middle and rear sections to receive auxiliary working gas and generating a swirl in the same.

Abstract: A plasma torch 1 used in plasma-arc welding is provided with a rod-shaped electrode 10, a first cylindrical nozzle 11 which is provided to surround the electrode 10 and which injects a plasma gas and a second cylindrical nozzle 12 which is provided to surround the first nozzle 11 and which injects a shielding gas. A second injection opening 121 of the second nozzle 12 directs in a substantially parallel direction with respect to an axial direction of the electrode 10 or in a direction being away from the electrode 10, and a plurality of groove portions inclining with respect to the axial direction of the electrode 10 are formed in an outer circumferential surface of the first nozzle 11 or an inner circumferential surface of the second nozzle 12.

Abstract: A process for the jet cutting of arcuate openings in a metal workpiece such as steel, by means of creating a jet along a predetermined axis, applying the jet to the workpiece, with the axis of the jet offset from the perpendicular, and rotating the jet around to describe the arc desired while maintaining the non perpendicular axis and terminating the cutting path just prior to completion of the opening.

Abstract: A machined ceramic article having an initial surface defect density and an initial surface roughness is provided. The machined ceramic article is heated to a temperature range between about 1000° C. and about 1800° C. at a ramping rate of about 0.1° C. per minute to about 20° C. per minute. The machined ceramic article is heat-treated in air atmosphere. The machined ceramic article is heat treated at one or more temperatures within the temperature range for a duration of up to about 24 hours. The machined ceramic article is then cooled at the ramping rate, wherein after the heat treatment the machined ceramic article has a reduced surface defect density and a reduced surface roughness.

Abstract: A plasma welding torch that can be reduced in size more than in conventional cases. When an inert gas G such as argon gas is supplied to an outer circumferential space around a non-consumable electrode 13, a portion of the inert gas G is used as plasma gas GP that forms a plasma arc PA between the non-consumable electrode 13 and a base material 2 via a plasma orifice 51. A plasma welding torch 1 moves, maintaining this state, in the direction of the arrow shown in FIG. 4. Meanwhile, a portion of the inert gas G supplied to a gas flowing part 21 is not used as the plasma gas GP but is used as shielding gas GS and is ejected onto the base material 2 ahead in the welding direction via a shielding orifice 52. The welding on the base material 2 is performed in a state where the plasma arc PA and the base material 2 are shielded from the air by this shielding gas.

Abstract: A consumable for a plasma arc torch, such as a nozzle, having a body and a head defining a shoulder portion having a frusto-conical portion and a flared portion. The flared portion increases the cross-sectional thickness to provide a greater heat-conduction path for removal of heat generated by a plasma arc, thereby extending consumable life. The frusto-conical portion provides a sharper, pointier nozzle head to simultaneously increase the operator's visibility of the workpiece. Methods of making and using the consumables are also included.

Abstract: A dual resistance heater for a phase change material region is formed by depositing a resistive material. The heater material is then exposed to an implantation or plasma which increases the resistance of the surface of the heater material relative to the remainder of the heater material. As a result, the portion of the heater material approximate to the phase change material region is a highly effective heater because of its high resistance, but the bulk of the heater material is not as resistive and, thus, does not increase the voltage drop and the current usage of the device.

Abstract: A microhollow cathode discharge assembly capable of generating a low temperature, atmospheric pressure plasma micro jet is disclosed. The microhollow assembly has two electrodes: an anode and a cathode separated by a dielectric. A microhollow gas passage is disposed through the three layers. In some embodiments, the passage is tapered such that the area at the first electrode is larger than the area at the second electrode. When a potential is placed across the electrodes and a gas is directed through the gas passage, then a low temperature micro plasma jet can be created at atmospheric pressure or above.

Abstract: Method of controlling the wear of at least one of the electrodes of a plasma torch including two electrodes having the same main axis, and being separated by a chamber designed to receive a plasma-generating gas, and at least one element for generating a magnetic field placed locally to the at least one electrode for which the control of wear is sought, in which the arc root is made to sweep longitudinally over a portion of the surface of this electrode from an initial position until the arc root reaches a defined final position of the portion, the longitudinal progression of the arc root being defined by a function dependent on at least the time, f(t), which is fixed.

Abstract: A special-purpose plasma arc torch for gouging grooves in a metal workpiece includes an angled nozzle having a bore made up of a first bore portion and a second bore portion that makes an angle of about 15° to about 75° with the first bore portion. The nozzle includes a proximal portion and a distal portion, the proximal portion being adapted for surrounding an electrode assembly when the nozzle is installed in the torch, the distal portion being adapted such that a part of the distal portion extends beyond a front face of an electrode of the torch. The part of the distal portion extending beyond the front face of the electrode has an exterior shape other than cylindrical or conical, and preferably has a non-axisymmetric shape that makes it suitable for fitting within a deep groove in a workpiece.

Abstract: A microhollow cathode discharge assembly capable of generating a low temperature, atmospheric pressure plasma micro jet is disclosed. The microhollow assembly has at two electrodes: an anode and a cathode separated by a dielectric. A microhollow gas passage is disposed through the three layers, preferably in a taper such that the area at the anode is larger than the area at the cathode. When a potential is placed across the electrodes and a gas is directed through the gas passage into the anode and out the cathode, along the tapered direction, then a low temperature micro plasma jet can be created at atmospheric pressure. Selection of gas microhollow geometry and operational characteristics enable the application of the assembly to low temperature treatments, including the treatment of living tissue.