A plasma apparatus of a plasma processing system is provided. The plasma apparatus defines a toroidal plasma channel and includes multiple end blocks defining respective portions of the toroidal plasma channel. Each end block includes an end-block tube constructed from a first electrically conductive material and a dielectric coating disposed on an interior surface of the end-block tube. The plasma apparatus also includes multiple mid-blocks defining respective portions of the toroidal plasma channel. Each mid-block includes at least one heat sink located adjacent to a substantially linear tube with a thermal interface disposed therebetween. The thermal interface is in physical communication with the tube and the at least one heat sink. The mid-block tube has a substantially uniform wall thickness and is constructed from a dielectric material. The at least one heat sink is constructed from a second electrically conductive material.

An apparatus for plasma control is disclosed. The apparatus comprises: a plasma generator comprising two electrodes, an anode and a cathode, configured to produce a plasma between the two electrodes; a solenoid coil disposed to surround the plasma and configured to produce a magnetic field parallel to a longitudinal axis between the two electrodes; and circuitry configured for allowing independent timing of the magnetic field with respect to the production of the plasma. A method for plasma control in a spectroscopy system and an optical emission spectrometer using said method are also disclosed.

The present application relates to a plasma atomization process and apparatus for producing metallic powders from at least one wire/rod feedstock. In the process, an electrical arc is applied between the at least one wire/rod feedstock, and a plasma torch is employed to generate a supersonic plasma stream at an apex at which the electric arc is transferred to the at least one wire/rod to melt and atomize the at least one wire/rod feedstock to produce the metallic powders. An anti-satellite diffuser is employed to prevent recirculation of the powders in order to avoid satellite formation.

An erosion of an electrode is prevented in a spark plug that performs an ignition by use of a spark discharge and an electromagnetic wave. The spark plug that a pulse voltage for a spark discharge and an electromagnetic wave supplied into the spark discharge as an energy are applied to a center electrode, the spark plug comprises the center electrode, an insulator including an axis hole into which the center electrode is engaged, a ground electrode configured to form a space between the ground electrode and the center electrode in which the spark discharge is generated, and a cylindrical conductor that is arranged at an outer circumference of the insulator, and an annular member is formed at an inner circumference of the cylindrical conductor and at a position where a distance from a distal end surface of the cylindrical conductor is within a range between wavelength and wavelength of the electromagnetic wave.

An igniter that has a large ignition power and an electromagnetic wave resonance structure with a small reflected power is provided. An igniter comprises a first rectangular substrate and a second rectangular substrate each having a longitudinal side, and at least one intermediate substrate arranged between the first substrate and the second substrate and having a longitudinal side which is shorter than each longitudinal side of the first substrate and the second substrate, the first substrate has an input part configured to receive an input of an electromagnetic wave from an outside, a first electrode, and an electromagnetic wave transmission line that connects the input part to the first electrode, each of the first electrode and the electromagnetic wave transmission line being provided at a surface of the first substrate on a side of the at least one intermediate substrate, the second substrate has an electromagnetic wave resonator and a second electrode that is electrically connected to the electromagnetic wave resonator, each of the electromagnetic wave resonator and a second electrode being provided at a surface of the second substrate on a side of the at least one intermediate substrate, and a space is formed between the first substrate and the second substrate at a position at which the at least one intermediate substrate does not exist therebetween, such that the first electrode and the second electrode are faced each other and located away from each other across the space and a part of the electromagnetic wave transmission line and a part of the resonator are faced each other and located away from each other across the space.

An ignition plug includes a center electrode; a cylindrical insulator that surrounds at least the circumference of a front end portion of the center electrode and that includes a bottom portion at the front side; and a cylindrical metal shell that holds the insulator from the outer circumference side. The center electrode includes a shaft portion that extends along an axial line and a head portion disposed at a front end of the shaft portion. The head portion has a width greater than that of the shaft portion in the radial direction. The insulator includes a first and second insulator. The first insulator has an axial hole and a diameter smaller than the maximum diameter of the head portion. The second insulator is joined to the first insulator. The shaft portion is disposed in the axial hole of the first insulator. The second insulator encloses the head portion.

An ignition plug includes a center electrode; a cylindrical insulator that surrounds at least the circumference of a front end portion of the center electrode and that includes a bottom portion at the front side; and a cylindrical metal shell that holds the insulator from the outer circumference side. The center electrode includes a shaft portion that extends along an axial line and a head portion disposed at a front end of the shaft portion. The head portion has a width greater than that of the shaft portion in the radial direction. The insulator includes a first and second insulator. The first insulator has an axial hole and a diameter smaller than the maximum diameter of the head portion. The second insulator is joined to the first insulator. The shaft portion is disposed in the axial hole of the first insulator. The second insulator encloses the head portion.

A spark plug includes: a center electrode; an insulator having a through hole around a part of the center electrode; and a metal shell holding the insulator from an outer peripheral side thereof. The metal shell includes a shelf portion that projects radially inward. The insulator includes an engagement portion engaged with the shelf portion from the front side, and a front end portion at the front side with respect to a front end of the metal shell. The front end portion has an outer diameter larger than an inner diameter of the metal shell at the front side with respect to the shelf portion. The front end portion of the insulator has a diameter-enlarged portion at which a diameter of the through hole increases and which is spaced apart from an outer peripheral surface of the center electrode.

A spark plug includes: a center electrode; an insulator having a through hole around a part of the center electrode; and a metal shell holding the insulator from an outer peripheral side thereof. The metal shell includes a shelf portion that projects radially inward. The insulator includes an engagement portion engaged with the shelf portion from the front side, and a front end portion at the front side with respect to a front end of the metal shell. The front end portion has an outer diameter larger than an inner diameter of the metal shell at the front side with respect to the shelf portion. The front end portion of the insulator has a diameter-enlarged portion at which a diameter of the through hole increases and which is spaced apart from an outer peripheral surface of the center electrode.

An ignition apparatus is provided which ignites a mixture of air and fuel gas by plasma to generate an initial flame. The apparatus includes: a spark plug that includes an inner conductor, a cylindrical outer conductor that holds the inner conductor thereinside, and a dielectric that is provided between the inner conductor and the outer conductor, and that generates plasma in a plasma formation space between the inner conductor and the outer conductor; an electromagnetic wave power supply that generates an electromagnetic wave to apply electromagnetic wave power to the spark plug; an evaluation section that evaluates a state of formation of the plasma; a determination section that determines a matching object of the electromagnetic wave based on an evaluation result by the evaluation section; and a coupled state control section that controls a matching condition of the electromagnetic wave so that the electromagnetic wave matches the matching object.