An optical waveguide is formed using a gas-enclosed vessel that has an internal space in which a polyvalent ionizable gas is enclosed, a laser beam irradiation unit, and a discharge circuit that causes a pulse current to flow in the gas-enclosed vessel at an initial current value. The pulse current is increased from the initial current value to a subsequent current value greater than the initial current value, and a polyvalent ionization channel is formed in the internal space, while increasing the pulse current, by irradiating the internal space in the plasma state with a trigger laser beam generated by the pulse laser beam irradiation device. The polyvalent ionization channel expands by an inverse pinch effect after the internal space is irradiated with the trigger laser beam due to a concentration of the pulse current in the internal space.

Disclosed is a demountable tube for a plasma torch assembly, such as an ICP torch assembly. The tube includes an open tubular body for radially surrounding a plasma within the tubular body. The tubular body may comprise a wall; and a mounting feature projecting from the tubular body for at least one of: (i) controlling alignment of the tubular body with respect to a mounting portion of the torch assembly, and (ii) releasably securing the tubular body to a portion of the torch assembly. The tubular body may also have a transmission zone that is partially devoid of said wall and includes at least one hole through said wall. The tube may be opaque. A plasma torch and ICP spectroscopy system are also disclosed.

Aspects and embodiments relate to plasma torch device component monitoring, a plasma torch device component monitoring system and a plasma torch device including such a monitoring system or suitable for use with such a system. The monitoring method comprises: collecting electromagnetic radiation generated by a plasma torch in a plasma torch device; analysing the collected electromagnetic radiation generated by the plasma torch; comparing the analysed electromagnetic radiation generated to known electromagnetic radiation associated with one or more components of the plasma torch device; and triggering one or more actions in the event that the analysed emission differs from the known emission. Such a monitoring method can allow for ameliorative action to be taken in the event that degradation of one or more components forming the device is detected.

An apparatus for diagnostics of neutral radicals in plasma, the apparatus comprising: a portable probe configured to be attached to and extend into a plasma chamber to obtain information from plasma contained in the plasma chamber, the probe comprising a metallic rod configured to be biased with an alternating current voltage applied to the probe to obtain current measurements; a transparent dielectric sleeve having a large bandgap configured to allow light transmission to obtain optical emission spectra from the plasma; and an insulated thermocouple junction provided in the metallic rod, the thermocouple junction configured to measure equilibrium temperature of the probe.

Certain embodiments described herein are directed to devices, systems and methods that comprise asymmetric induction devices. In some instances, the device can include a plurality of plate electrodes which can be spaced asymmetrically or a plurality of coils which can be spaced asymmetrically.

A high-frequency input voltage and a high-frequency input current to a series resonant circuit are detected by a voltage detection unit and a current detection unit, respectively, and plasma input power is detected by a plasma input power detection unit based on the detected high-frequency input voltage and high-frequency input current. By directly detecting the plasma input power in this manner, the plasma input power may be accurately controlled regardless of the state of a plasma-generating gas or an analysis sample. Also, use of a switching circuit including a semiconductor device allows an inexpensive configuration compared with a configuration where a vacuum tube or the like is used.

A method of determining a peak intensity in an optical spectrum is described. The method includes producing a two-dimensional array of spectrum values by imaging the optical spectrum onto a detector array. An offset using an actual location and an expected location of a peak of an interpolated subarray is used to adjust an expected location of another peak that is within another two-dimensional subarray. Interpolated spectrum values are then used to produce a peak intensity value of the second peak.

A high-frequency input voltage and a high-frequency input current to a series resonant circuit are detected by a voltage detection unit and a current detection unit, respectively, and plasma input power is detected by a plasma input power detection unit based on the detected high-frequency input voltage and high-frequency input current. By directly detecting the plasma input power in this manner, the plasma input power may be accurately controlled regardless of the state of a plasma-generating gas or an analysis sample. Also, use of a switching circuit including a semiconductor device allows an inexpensive configuration compared with a configuration where a vacuum tube or the like is used.

Provided are a plasma generation apparatus including a measurement device and capable of controlling conditions of plasma properly and stably, and a plasma thruster using the plasma generation apparatus. A plasma generation apparatus including a measurement device of the present invention includes a discharge vessel, a light-emitting monitor, a probe measuring instrument, a control device, and an optical axis driving unit. The discharge vessel ionizes gas which is introduced to an inside thereof so as to generate plasma. The light-emitting monitor measures electron density of the plasma by emission spectra of the plasma. The probe measuring instrument measures the electron density of the plasma by a probe disposed in the discharge vessel.

A plasma source chamber (10) for use in a spectrometer comprises an inner housing (11) for accommodating a plasma source (31) and an outer housing (12) accommodating the inner housing. The outer housing (12) comprises at least one outer air inlet opening (21) in a first wall and at least one outer air outlet opening (22) in a second wall. Walls of the inner housing and walls of the outer housing define a spacing (25) so as to allow a first air flow (1) from the at least one outer air inlet opening (21) to the at least one outer air outlet opening (22) through the spacing (25) between the inner housing and the outer housing. The inner housing (11) comprises at least one inner air inlet opening (23) in a first wall and at least one inner air outlet opening (24) in a second wall to allow a second air flow (2) from the at least one inner air inlet opening to the at least one inner air outlet opening through the inner housing. Thus, an improved cooling of the outer surfaces of the plasma source chamber is achieved.