Abstract: A DCP spectrometer emission source for creating a conical high temperature plasma through which an aerosol suspended sample is able to penetrate which generally includes at least three D.C. powered electrodes, a base structure for circumferentially spacing the electrodes about a central axis, and an introduction conduit associated with the central axis for injecting the aerosol sample stream into the conical shaped plasma created by the electrodes. The base structure circumferentially spaces the electrodes about the central axis such that the longitudinal axes of the electrodes converge radially toward the central axis at an acute angle to the central axis. Each of the electrodes has an electrode member and a conduit for conveying an ionizable gas passed the electrode members. The electrode members are also connected to a source of D.C. electrical power such that two of the electrode members have the same polarity and the third electrode member has the opposite polarity.

Abstract: A radio frequency excitor apparatus and method produce an inductively coupled plasma to heat an analytic sample. The apparatus includes a radio frequency generator mechanism for producing electrical power of selected radio frequency. The generator mechanism has a power output tuning mechanism comprised of at least one output tuning inductor for determining the generator radio frequency. A separate plasma load circuit is coupled to the generator mechanism and is comprised of a work coil and a series connected, impedance matching capacitor. The work coil is adapted to produce an inductively coupled plasma and the capacitor is adapted to substantially balance the combined inductive reactances of the work coil and plasma. A control mechanism for controlling the power input into the plasma load circuit stabilizes the plasma.

Abstract: Improvements on a DC plasma jet generator for emission spectrochemical analysis wherein two anode blocks and one cathode block are positioned in an inverted Y shape, and each of the anode blocks has a cylinder, a piston, an an anode received by a recess in the end of the piston. Each anode can be secured in the recess at the end of the piston in the corresponding anode block by magnetic force. Each of the anode and cathode blocks is pivotable so that the associated electrode attached to each block can be fixed upright with the free end thereof directed upward. This means that the electrodes can be replaced easily as well as speedily by remote control using manipulators.

Abstract: A device for monitoring the arc of a plasma burner employs a photo-sensitive device to receive light from the plasma arc via at least one narrow band filter, the wavelength range of the filter being centered on the spectral response characteristic of a material in the burner or the plasma nozzle. A monitoring circuit detects when the output of the photo-sensitive device increases, indicating fault conditions in the arc.

Abstract: A fluorescence spectrometer for multielement analysis including a source for atomizing a dispersed sample along an axis and a plurality of energizers and detectors preferably arranged in pairs about the source, with each of the pairs designed for analyzing one element. Preferably, the source is an inductively coupled plasma. Means is provided for each of the pairs to view a different segment of the source along its axis, depending on the element to be analyzed. Preferably, such means includes: a source movable along its axis; fiber optics interposed between the energizers and the source and between the source and the detectors; and a movable optical element interposed between the energizers and the source and between the source and the detectors. The spectrometer further features a polychromator for use in lieu of matched optical filters in the detectors and demountable hollow cathode lamps as energizers.

Abstract: A heat shield for a sample introduction tube for a plasma jet device is disclosed, comprising a hollow cylindrical member disposed around the sample introduction tube, the hollow cylindrical member is provided with a reflective exterior and heat dissipating fins.

Abstract: A glass fiber, strand or a product made of glass fibers is made to pass through a chamber irradiated with high-frequency radiation, so that, if the electrically conductive matters are contained, a high-frequency electric discharge occurs in the chamber accompanied by generation of light. The presence of the electrically conductive matters is made known by detecting this light by a photosensor.

Abstract: A high frequency induction coupled plasma torch is disclosed. The torch is comprised of a multi-pipe structure and is used for forming a plasma flame by high frequency power induction. The torch is comprised of a plurality of pipes which are coaxially arranged within each other. Each of the pipes has one or more flanged openings positioned on its surface whereby it is interconnected to the adjacent pipe. By means of the flanged openings any given pipe may be interconnected with any number of outer pipes. The torch can be economically produced and maintained.

Abstract: A concentric micro-nebulizer and method for introducing liquid samples into a plasma established in a plasma torch including a first tube connected to a source of plasma gas. The concentric micro-nebulizer has inner and outer concentric tubes extending upwardly within the torch for connection to a source of nebulizer gas and to a source of liquid solvent and to a source of sample liquid. The inner tube is connected to the source of liquid solvent and to the source of sample liquid and the outer tube is connected to the source of nebulizer gas. The outer tube has an orifice positioned slightly below the plasma when it is established, with the inner and outer tubes forming an annulus therebetween with the annular spacing between the tubes at said orifice being less than about 0.05 mm. The dead volume of the inner tube is less than about 5 microliters.

Abstract: A fluorescence spectrometer for multielement analysis including a source for atomizing a dispersed sample along an axis and a plurality of energizers and detectors preferably arranged in pairs about the source, with each of the pairs designed for analyzing one element. Preferably, the source is an inductively coupled plasma. Means is provided for each of the pairs to view a different segment of the source along its axis, depending on the element to be analyzed. Preferably, such means includes: a source movable along its axis; fiber optics interposed between the energizers and the source and between the source and the detectors; and a movable optical element interposed between the energizers and the source and between the source and the detectors. The spectrometer further features a polychromator for use in lieu of matched optical filters in the detectors and demountable hollow cathode lamps as energizers.

Abstract: A plasma monitor which measures the distribution of particular chemical species (atom, molecule, ion) in plasma generated inside an instrument making use of the plasma. Laser light having a particular wavelength is radiated to the particular chemical species so as to let it generate fluorescence. The fluorescence is picked up for each of a plurality of zones divided in the radiating direction of the laser light and the construction of the chemical species in each zone is determined on the basis of the intensity of the fluorescence in each zone in order to determine the concentration distribution of the particular chemical species contained in the plasma. The operative condition within the sealed vessel can be grasped more accurately by measuring the distribution of the concentration of the chemical species which is closely related with the condition of deposition or etching.

Abstract: A spectroanalytical system includes induction coupled plasma apparatus for exciting sample material to an atomic state for analysis, a source of transport gas, a sample chamber for receiving a sample to be analyzed, and heating means for vaporizing a sample to be analyzed in the chamber and forming particles of the sample of sufficiently small size to form an aerosol. The sample chamber is connected in a flow path between the source of transport gas and the plasma apparatus. A supplemental chamber surrounds the sample chamber, and gas is flowed to the supplemental chamber at a higher rate than the gas flow to the sample chamber. A flow restriction between the sample and supplemental chambers normally permits flow of gas from the supplemental chamber into the sample chamber but also provides pressure relief upon rapid heating for sample vaporization that is effective to minimize pressure transients in the aerosol stream that depress the output signal of the plasma apparatus.

Abstract: A plasma burner or torch for emission spectrometry comprises an induction coil for generating a plasma, an outer jacket, an inner jacket coaxial therewith, a sleeve inside the inner jacket and coaxial therewith, a capillary tube inside the sleeve and oriented along the axis of symmetry, a cooling gas feed line, a plasma gas feed line, and an aerosol gas feed line. The distance of the sleeve from the inner jacket of the plasma burner is advantageously smaller than the distance between the sleeve and the capillary tube. The sleeve preferably consists essentially of quartz. In such a plasma torch, the rate of consumption of the plasma gas as well as of the cooling gas is reduced, while the detection power of the device for elements such as boron, iron, magnesium, phosphorous and zinc is comparable to conventional standard burners.

Abstract: A plasma monitoring method and a plasma monitor in a dry process which utilizes a plasma. Among a large number of chemical species which constitute the plasma, one or two specified chemical species suited to grasp the situation of the dry process has/have its/their plasma light/lights detected so as to obtain the three-dimensional distribution of the densities of the single specified chemical species or the ratios of the two specified chemical species in the plasma.

Abstract: An apparatus and method for analyzing a sample of an inorganic or organic material, wherein the sample is in a discharge tube within a plasma cavity interfaced to an analytical device and a high frequency-sustained radiation-induced excitation plasma is initiated and sustained in the plasma cavity, which plasma is capable of causing the sample to pyrolyze and emit radiation, which emitted radiation or resulting atomic and molecular constituents may be analyzed,the improvement comprising:means for fixing or immobilizing the sample at a position spaced apart from the plasma, andmeans for elongating the plasma so as to cause it to encompass the sample.

Abstract: A spectroanalytical method includes the steps of exciting material to spectroemissive levels, dispersing radiation from the excited sample material into a spectrum, positionally locating a reference constituent of the excited material in the spectrum, the reference constituent having a known wavelength offset from an element of interest in the sample material to be analyzed, and then shifting the known wavelength offset by an essentially hysteresis free mechanism and making an analytical measurement at that wavelength offset position of radiation produced by a spectrum from sample material that has been excited to spectroemissive levels.

Abstract: A chromatographic system that utilizes one detection system for gas chromatographic and micro-liquid chromatographic determinations. The detection system is a direct-current, atmospheric-pressure, helium plasma emission spectrometer. The detector utilizes a non-transparent plasma source unit which contains the plasma region and two side-arms which receive effluents from the micro-liquid chromatograph and the gas chromatograph. The dual nature of this chromatographic system offers: (1) extreme flexibility in the samples to be examined; (2) extremely low sensitivity; (3) element selectivity; (4) long-term stability; (5) direct correlation of data from the liquid and gas samples; (6) simpler operation than with individual liquid and gas chromatographs, each with different detection systems; and (7) cheaper than a commercial liquid chromatograph and a gas chromatograph.

Abstract: Disclosed is a novel apparatus for the production of a sustained inductively coupled non-argon plasma discharge in flowing gas in a 13-25 mm (analytical size) containment tube at atmospheric pressure. The apparatus is developed for elemental analysis of injected aerosol or powdered samples, and particularly for air monitoring applications.

Abstract: In a direct current plasma emission spectrometer for use in combination with a micro-column liquid chromatograph, an improved plasma source unit. The plasma source unit includes a quartz capillary tube having an inlet means, outlet off gas means and a pair of spaced electrodes defining a plasma region in the tube. The inlet means is connected to and adapted to receive eluant of the liquid chromatograph along with a stream of plasma-forming gas. There is an opening through the wall of the capillary tube penetrating into the plasma region. A soft glass capillary light pipe is disposed at the opening, is connected to the spectrometer, and is adapted to transmit light passing from the plasma region to the spectrometer. There is also a source of electromotive force connected to the electrodes sufficient to initiate and sustain a plasma in the plasma region of the tube.

Abstract: A scanning monochromator system comprises a housing, structure defining entrance and exit apertures, and a radiation dispersing component in the housing arranged to disperse radiation passing through the entrance aperture into a spectrum for transmission towards the exit aperture. The dispersing element is directly coupled to an electromagnetic drive transducer with the assembly of a rotary component of the drive transducer and the dispersing component being mounted for rotation as a unit about a stationary axis that is perpendicular to the optical axis of the system so that a selected portion of the radiation dispersed by the dispersing component is passed through the exit aperture. The drive transducer is arranged to move a selected portion of dispersed radiation at the exit aperture over a wavelength range of at least 3000 angstroms with a reproducible accuracy of better than 0.03 angstroms in less than one second.

Abstract: A sample transport and manipulation system and method for exciting a quantitatively uniform sample for spectrometric analysis over an extended period of time is disclosed. A uniform sample transport medium such as a filament is transported at a uniform rate through an excitation situs which is coincident with the optical input situs of the spectrometer. Means for uniformly depositing a liquid sample over the medium are included to complete the establishment of a system in which the spectrometer is presented with a quantitatively uniform excited sample on a continuous basis.

Abstract: Circuitry for the generation and synchronous detection of optical pulsed signals contaminated by additive background noise characterized by a high signal-to-noise ratio. The circuitry comprises a source for generating optical pulsed signals, a detector for generating detector signals in response to the optical pulsed signals, and a signal processor for processing the detector signals in synchronism with the optical pulsed signals. The signal processor for processing the detector signals includes a high pass filter, an integrator and at least one switch synchronized with the optical pulsed signals for driving the integrator. The circuitry is preferably under computer control.

Abstract: A fluorescence spectrometer for multielement analysis including a source for atomizing a dispersed sample along an axis and a plurality of energizers and detectors preferably arranged in pairs about the source, with each of the pairs designed for analyzing one element. Preferably, the source is an inductively coupled plasma.Means is provided for each of the pairs to view a different segment of the source along its axis, depending on the element to be analyzed. Preferably, such means includes: a source movable along its axis; fiber optics interposed between the energizers and the source and between the source and the detectors; and a movable optical element interposed between the energizers and the source and between the source and the detectors.The spectrometer further features a polychromator for use in lieu of matched optical filters in the detectors and demountable hollow cathode lamps as energizers.

Abstract: An optical coupling device for providing an oxygen-free optical path between a plasma torch and a monochromator includes a hollow body having means associated therewith for the venting thereof.

Abstract: An apparatus and method for controlling a plasma etching reaction. The plasma reaction is controlled by monitoring the output voltage of an optical detector which is responsive to emissions emanating from the reaction. As the output of the detector changes indicating that the first portion of the etching process has been completed, the average power density supplied to the reaction is reduced by switching the applied power from a continuous wave to a pulsed mode. The reaction is allowed to continue to completion in the reduced power mode.

Abstract: Method of concentrating a low-concentration element in a solution and removing other, high-concentration elements, using an ion exchange resin specific to the element to be concentrated.The resin is disposed in a mini-column less than 3 mm in diameter into which the solution is made to pass, the elution of the element from the resin is carried out by using a very small volume of elution liquid.The invention applies to quantitative analysis by emission spectrum in an inductive plasma, and in this case the whole of the small volume of elution liquid, previously nebulized, is simultaneously supplied to the plasma.

Abstract: There is disclosed herein a novel spectral background corrector system which, by employing light refracting techniques, causes wavelength scanning or modulation which allows substantial elimination of spectral background.

Abstract: A method and apparatus for mineral, in particular hydrocarbon exploration in which determination is made of whether substances indicative of a deposit are present in the atmosphere in the form of charges, molecules or clumps of molecules. Intaken air is purged of particles and only small naturally charged molecules or clumps are transferred to, for instance, an inert gas for spectroscopic examination.

Abstract: High frequency inductive generator for the inductive coil of a plasma generator constituted by a head for inflow of gas into an inductive coil. The high frequency generator has a quarter wave anode resonant line oscillator circuit and a coupling circuit connected to the inductive coil. The quarter wave anode circuit is controlled from a single oscillator tube. One of the lines is connected to the anode of the tube, while the other is coupled exteriorly by capacitive coupling.The invention is used for analysis by emission spectrometry.

Abstract: A method for determination of pyrite and sidermite content in core samples is disclosed wherein the method involves a two-step digestion of the minerals in hydrochloric and nitric acids and analysis of the solutions using an inductively coupled plasma atomic emission spectrometer.

Abstract: A highly accurate, rapid scanning monochromator type of spectroanalysis system employs a source of the plasma emission type, a filtering monochromator, and a resolving monochromator. Each monochromator has a dispersing element and the two dispersing elements are arranged to be moved simultaneously but at different rates such that the spectral order of radiation from the source as dispersed by the first dispersing element is different from the spectral order of radiation dispersed by the second dispersing element, together with selectively operable control means for moving the two dispersing elements simultaneously and at the same rate.

Abstract: A VUV plasma atomic emission apparatus system and method is distinguished by the features of a plasma purge chamber about the plasma generated by the system, a chromator in optical communication and closed gaseous communication with said plasma, preferably through a common port in said plasma purge chamber, purge gas supply means for purging said chromator and ultimately said plasma purge chamber through said common port, vent means preferably operable by draft to continuously exhaust gases from said plasma purge chamber, and focusing means between the plasma and chromator for focusing light from an excited sample introduced into or near said plasma onto said chromator. The continuous gas purging feature establishes a steady state gaseous environment of minimum absorption characteristics to the specific wavelengths of interest, thus expanding the energy band that may be reliably detected (i.e.

Abstract: A method and apparatus for analysis of atomic species which comprises directly forming metastable energy level nitrogen by processing a stream of nitrogen containing gas through a dielectric field wherein essentially no excited species above the 6th vibrational level of the B.sup.3 .pi..sub.g energy state nor nitrogen atoms nor ions are formed, admixing said excited nitrogen with a gas stream suspected of containing said atomic species to be analyzed whereby the energy level of said species is raised sufficiently to enable a fluorescent emission as the energy level of said excited species decays to its lower energy state, detecting and analyzing the spectrum of said flluroescent radiation to determine the identity and concentration of said element.

Abstract: An induction plasma system includes a plasma chamber, a high frequency electrical coil that surrounds the chamber, and an oscillator for energizing the coil to establish a plasma maintaining condition in the chamber. The oscillator tank circuit includes the coil, and is tuned so that it is essentially at resonance when a plasma condition is established in the chamber. Ignition means is arranged for initiating a plasma condition, and is constructed such that insertion of the ignition means into the chamber in the absence of a plasma condition shifts the impedance condition in the chamber to essentially the same tuned condition that exists when a plasma condition is established in the plasma chamber, but without need to adjust any component of the tank circuit.

Abstract: An inductively coupled plasma atomic fluorescence spectrometer (ICP-AFS) for multielement analysis of unknown samples. The ICP-AFS spectrometer comprises a plasma stream atomizing a dispersed sample and directed along a central axis, a plurality of optical stations surrounding the central axis, each including an energizing illuminator and a fluorescence detector focused at the same region of the plasma stream, and a readout system for identifying the unknown samples. Preferably, the plasma stream is controlled by inductive coupling, the energizing illuminator is a modified hollow cathode lamp, the fluorescence detector includes an interference filter, and the readout system incorporates multiplexing and intermittent modulation of the energizing illuminators.

Abstract: An inductively coupled plasma torch (ICP) provides an efficient means for ermally degrading many organic molecules and exciting the resulting atomic species into optical emission. Spectrometric analysis produces reliable data for qualitative and quantiative simultaneous, multi-element analyses. To determine the empirical formula of a molecular compound, a gas chronometer is used to separate a mixture and atomic emission monitored continuously by a multi-channel spectrometer over the period of time required for the rise and fall of the elution. The plural channels provide parallel outputs defining intensity relationships or ratios of the excited elements. Instantaneous sampling repetitively made during the elution period provides a large number of discrete ratios that are averaged to provide the desired empirical formula. Molecular formulas then are derivable.

Abstract: End point detection in developing photoresist is accomplished by monitoring the output of a photodetector and sensing a plateau in the output.

Abstract: Long-term stability for an emission type plasma spectrometer is provided by automatically adjusting the output of a power supply which is being utilized to create the plasma. The automatic adjustment is based on a feedback signal which is derived by monitoring an atomic line of a carrier gas.

Abstract: In a system for analyzing the elemental or molecular composition of a sample where the sample components are excited through collision with an active metastable gaseous species, the excited sample components emitting a characteristic wavelength of light which may be detected, the system including a microwave cavity through which the gaseous species flows and a microwave source coupled to the cavity, the microwave discharge exciting the gaseous species, there is disclosed an improved gas and sample introduction system wherein a liquid sample and a water soluble compound are mixed with a diluent and aspirated into the flow, upstream of the microwave cavity, onto a heated filament, the compound being capable of releasing nitrogen or some other suitable gas molecules at high temperature and low pressure whereupon formation of nitrogen and vaporization of the sample occur simultaneously.

Abstract: A sample stream of liquid representative of the environment such as sea water or lake water or drilling mud is subjected to the passage therethrough of an inert carrier gas to entrain chemical components and particulate matter which is then removed from the sample stream for analysis of the chemical components and particulate matter.

Abstract: In a system for analyzing the elemental or molecular composition of a sample wherein the sample components are excited through collision with an active metastable gaseous species, the excited sample components emitting a characteristic wavelength of light which may be detected, the system including a microwave cavity through which the gaseous species flows and a microwave source coupled to the cavity, the microwave discharge exciting the gaseous species, there is disclosed an improved liquid sample introduction system which causes complete vaporization and disassociation of the sample. The sample is preferably aspirated directly into the microwave discharge within which the active gas is generated. A novel sample and gas injection probe is also disclosed.

Abstract: A method of detecting the presence of a coating of gaseous molecules on the surface of solid particulate material comprising the steps of entrapping the particulate material in a chemically inert carrier gas, heating the said material to release the gaseous molecules adsorbed on the particles, separating the particles from the carrier gas and the previously adsorbed gas molecules, passing the gases to a plasma, and spectroscopically analyzing the light emitted therefrom to detect the presence of the previously adsorbed gas.

Abstract: A spectral source comprises a lamp containing an anode and a cathode in an inert gas. The anode and cathode are different in shape and connected to a high-frequency power source to produce a high-frequency discharge between the anode and cathode to cause both sputtering of the cathode and excitation of a radiation having the spectrum according to the material sputtered from the cathode. The application of solely high-frequency power prevents adherence of the sputtered material to the interior walls of the lamp bulb thereby allowing a reduction of the dimensions of the lamp bulb, prolongating the life time of the lamp and increasing the stability and intensity of the radiation. A magnetic field may be applied to the radiation for Zeeman modulation. Due to the relatively small dimensions of the lamp bulb, relatively small and inexpensive magnets may be used.

Abstract: This invention provides different length glass fibers for providing a broad range of optical time delays for short incident chromatic light pulses for the selective spatial and frequency analysis of the light with a single light detector. To this end, the frequencies of the incident light are orientated and matched with the different length fibers by dispersing the separate frequencies in space according to the respective fiber locations and lengths at the input terminal of the glass fibers. This makes the different length fibers useful in the field of plasma physics. To this end the short light pulses can be scattered by a plasma and then passed through the fibers for analyzing and diagnosing the plasma while it varies rapidly with time.

Abstract: Trace impurities in flowing gases may be detected and measured by a dynamic atomic molecular emission spectrograph utilizing as its energy source the energy transfer reactions of metastable species, atomic or molecular, with the impurities in the flowing gas. An electronically metastable species which maintains a stable afterglow is formed and mixed with the flowing gas in a region downstream from and separate from the region in which the metastable species is formed. Impurity levels are determined quantitatively by the measurement of line and/or band intensity as a function of concentration employing emission spectroscopic techniques.

Abstract: A plasma jet device which comprises first and second anode electrodes spaced apart and positioned such that their axes, if extended, would intersect at an angle, and a third cathode electrode positioned offset from the plane formed by the extended axes of the first and second electrodes, the plasma jet device forming an ionized column of gas having the shape of an inverted Y and providing a stabilized excitation zone.

Abstract: A method of separating chemical coatings from particles is disclosed which may be used in the aerial prospecting for minerals or the determination of the chemical constituents of a dried liquid coating.The coating is volatized and ionized by passing the particle and its coating into a plasma. Separation is achieved by passing the particle through and beyond the plasma. The coating constituents may be spectroscopically analyzed by passing the coating constituents directly into a second plasma and viewing the light emitted therefrom.