Abstract: 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.

Abstract: Analytical instrument systems, components, and methods for stabilizing discharge formation are described. A spark gap device includes a first planar coil, defining an axis normal to a coil plane and defining a first aperture substantially centered about the axis. The spark gap device includes a second planar coil, offset from the first planar coil along the axis and substantially parallel with the coil plane, the second planar coil defining a second aperture substantially centered about the axis. The spark gap device also includes a conductive element disposed in the first aperture and substantially aligned with the axis.

Abstract: A method for compositional analysis includes providing a sample having a surface, moving an ablation point to a plurality of positions on the surface along a fractal path, pulsing an energy source to provide an electromagnetic energy beam to ablate material at the ablation point, collecting an emission spectrum in response to pulsing the energy source, and analyzing the emission spectrum to determine a composition at the surface.

Abstract: A spark stand for an optical emission spectrometer, comprising: a spark chamber; and at least one auxiliary gas conduit for providing an auxiliary gas flow into the spark chamber, wherein the at least one auxiliary gas conduit is configured to provide the auxiliary gas flow into the spark chamber for a period after spark operation but not during spark operation in which analysis of a sample takes place. The auxiliary gas flow into the spark chamber improves flushing of dust from the spark chamber after spark operation.

Abstract: A system and method for spectrometry of a sample in a plasma is described. The system includes a split ring resonator, an electrode, and a delivery system. The split ring resonator has a discharge gap, and the electrode is arranged in proximity to, but spaced apart from, the discharge gap such that. When a sufficient power is supplied to a plasma generated in the discharge gap, the plasma extends towards and couples with the electrode, so that the plasma is established in a region between the discharge gap and the electrode. The delivery system is for introduction of a sample into the plasma established in the region between the discharge gap and the electrode. The system is configured to direct an output from the plasma to a spectrometer for analysis.

Abstract: A multipass cell (300) comprising: a first reflector arrangement (305A, 305B); and a second reflector arrangement (307), the first (305A, 305B) and second (307) reflector arrangements defining an optical cavity (315) therebetween and the cell; wherein the first reflector arrangement (305A, 305B) is configured such that light incident on the first reflector arrangement (305A, 305B) is at least partially retroreflected towards the second reflector arrangement (307), wherein the second reflector (307) arrangement comprises a concave surface that is reflective, wherein at least one of the first (305A, 305B) and second (307) reflector arrangements comprises an aperture (306) for allowing light to enter and/or exit the optical cavity (315).

Abstract: Analytical instrument systems, components, and methods for stabilizing discharge formation are described. A spark gap device includes a first planar coil, defining an axis normal to a coil plane and defining a first aperture substantially centered about the axis. The spark gap device includes a second planar coil, offset from the first planar coil along the axis and substantially parallel with the coil plane, the second planar coil defining a second aperture substantially centered about the axis. The spark gap device also includes a conductive element disposed in the first aperture and substantially aligned with the axis.

Abstract: 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.

Abstract: A method for compositional analysis, in particular laser-induced breakdown spectroscopy (LIBS), includes providing a sample having a surface, moving an ablation point to a plurality of positions on the surface along an arc path defined by a plurality of arcs, wherein the plurality of arcs extend from an edge of the area to another edge of the area, wherein the arc path follows adjacent arcs of the plurality of arcs, pulsing an energy source to provide an electromagnetic energy beam to ablate material at the ablation point, collecting an emission spectrum in response to pulsing the energy source, and analyzing the emission spectrum to determine a composition at the surface.

Abstract: A method for controlling the flow of gas through a spectrometer, comprising: flowing a gas through a volume of the spectrometer, the volume being a volume through which light from a sample passes along a first path to reach a first detector and the gas being transparent to the light in a spectral region analysed by the spectrometer; transmitting light from a light source along a second path through the gas to a second detector; detecting an intensity of the light from the light source at the second detector at one or more wavelengths of the light; comparing the detected intensity of the light to a respective setpoint corresponding to a desired transmittance of the gas in the volume of the spectrometer and generating at least one error signal based on the comparison; and adjusting a flow rate of the gas through the volume of the spectrometer based on the error signal, in particular to minimise the difference between the detected intensity and setpoint.

Abstract: Disclosed herein are various systems and methods for optical emission spectroscopy. In some examples a substrate can be formed from conductive layers separated by a dielectric layer, the substrate having at least one recess therein, and the recess having a aperture therethrough. A chamber then encloses the area over the recess, the chamber including chamber walls, a gas inlet and a gas outlet to allow a gas to fill the chamber. An arc is then created across the substrate using the conductive layers. The arc may form a plasma using the gas inside the chamber. The plasma then ablates a surface of a specimen generating photons that can then be analyzed by a spectrometer.

Abstract: A method for compositional analysis includes providing a sample having a surface, moving an ablation point to a plurality of positions on the surface along a fractal path, pulsing an energy source to provide an electromagnetic energy beam to ablate material at the ablation point, collecting an emission spectrum in response to pulsing the energy source, and analyzing the emission spectrum to determine a composition at the surface.

Abstract: A double-pulse laser system for generating first and second laser pulses, comprising a multipass cell (300) arranged to delay the second laser pulse with respect to the first laser pulse, wherein the multipass cell comprises first (305A, 305B) and second (307) reflector arrangements defining an optical cavity (315) in which the delayed second laser pulse is reflected back and forth multiple times between the first (305A, 305B) and second (307) reflector arrangements to provide a temporal delay between the first and second pulses of 1 ns or greater.

Abstract: A multipass cell (300) comprising: a first reflector arrangement (305A, 305B); and a second reflector arrangement (307), the first (305A, 305B) and second (307) reflector arrangements defining an optical cavity (315) therebetween and the cell; wherein the first reflector arrangement (305A, 305B) is configured such that light incident on the first reflector arrangement (305A, 305B) is at least partially retroreflected towards the second reflector arrangement (307), wherein the second reflector (307) arrangement comprises a concave surface that is reflective, wherein at least one of the first (305A, 305B) and second (307) reflector arrangements comprises an aperture (306) for allowing light to enter and/or exit the optical cavity (315).

Abstract: A method for controlling the flow of gas through a spectrometer, comprising: flowing a gas through a volume of the spectrometer, the volume being a volume through which light from a sample passes along a first path to reach a first detector and the gas being transparent to the light in a spectral region analysed by the spectrometer; transmitting light from a light source along a second path through the gas to a second detector; detecting an intensity of the light from the light source at the second detector at one or more wavelengths of the light; comparing the detected intensity of the light to a respective setpoint corresponding to a desired transmittance of the gas in the volume of the spectrometer and generating at least one error signal based on the comparison; and adjusting a flow rate of the gas through the volume of the spectrometer based on the error signal, in particular to minimise the difference between the detected intensity and setpoint.

Abstract: A spark stand for an optical emission spectrometer, comprising: a spark chamber; a gas inlet for flowing gas into the spark chamber; a gas outlet for carrying gas from the spark chamber; wherein one or more internal surfaces of the spark chamber, gas inlet and/or gas outlet comprise an anti-adhesion material. The anti-adhesion material can enable reduced adhesion of ablated material, such as metallic dusts for example, onto the surfaces within the spark stand.