Abstract: Disclosed is an apparatus for separating ions including a plurality of first electrode portions, each first electrode portion of the plurality of first electrode portions having a first length and an outer surface that is at least partially curved in a direction transverse to the first length. The apparatus also includes a plurality of second electrode portions arranged in an alternating sequence with the plurality of first electrode portions, each second electrode portion of the plurality of second electrode portions having a second length and an outer surface that is curved in a direction transverse to the second length, a space between the outer surface of a first electrode portion and the outer surface of an adjacent second electrode portion defining a portion of an analytical gap for separating ions.

Abstract: A MALDI mass spectrometer includes a radiation source, such as a gas or solid state laser, that emits a beam of radiation (typically in the UV or IR wavelengths) directed along the central axis of a linear ion trap in which analyte ions and matrix cluster ions are confined. The radiation beam has a wavelength that is strongly absorbed by the matrix cluster ions. The absorption of radiation by the matrix cluster ions produces dissociation of the matrix cluster ion into fragments having mass-to-charge ratios that lie below a mass-to-charge ratio range of interest. Thus, chemical noise associated with matrix cluster ions is reduced or eliminated.

Abstract: A mass filter apparatus for filtering a beam of ions is described. The apparatus comprises an ion beam source and first and second mass filter stages in series to receive the ion beam. A vacuum system maintains the first and second filter stages at substantially the same operating pressure, below 10?3 torr. The first mass filter stage transmits only ions having a sub-range of mass-to-charge ratios including a selected mass-to-charge ratio. The second filter transmits only ions of the selected mass-to-charge ratio. The second mass filter can achieve high accuracy detection without being subjected to problems such as build-up of material on quadrupole rods, resulting in a distorted electric field close to the rods. The first mass filter acts as a coarse filter, typically transmitting 1% of ions received from the ion source. Thus, the detection accuracy and lifetime of mass spectrometers embodying this invention are greatly improved.

Abstract: A beam modulation device gate is constructed from a silicon material, such as a silicon layer on an silicon on insulator wafer. The device further comprises a set of electrical contacts on the layer. The layer defines a set of electrically conducting silicon material fingers forming an array, wherein each of at least some of the fingers is connected electrically to one of the electrical contacts. The gate may be used in a mass or ion mobility spectrometer. Where the gate is constructed from a silicon on insulator wafer, an insulator layer supports the silicon layer and a handle layer supports the insulator layer. When predetermined electrical potentials are applied to the electrical contacts, at least some of the fingers will be substantially at said predetermined electrical potentials to modulate a beam of charged particles that passes through said array of fingers.

Abstract: A mass spectrometer is provided for identifying mass and velocity distributions in a continuous ion beam is configured with a circular dispersive system creating a rotating electromagnetic field, which is capable of deflecting the ion beam from an initial direction, and a circular position-sensitive detector intercepting the deflected ion beam and providing information from which the ion mass-per-charge ratio is determined

Abstract: A CMOS time-of-flight “TOF” system-on-a-chip “SoC” for precise time interval measurement with low power consumption and high counting rate has been developed. The analog and digital TOF chip may include two Constant Fraction Discriminators “CFDs” and a Time-to-Digital Converter “TDC”. The CFDs can interface to start and stop anodes through two preamplifiers and perform signal processing for time walk compensation (110). The TDC digitizes the time difference with reference to an off-chip precise external clock (114). One TOF output is an 11-bit digital word and a valid event trigger output indicating a valid event on the 11-bit output bus (116).

Abstract: A mass spectrometer includes a magnetic sector configured to separate a plurality of ion beams, and an electrostatic sector configured to receive the plurality of ion beams from the magnetic sector and increase separation between the ion beams, the electrostatic sector being used as a dispersive element following magnetic separation of the plurality of ion beams. Other apparatus and methods are provided.

Abstract: Multiply charged ions are trapped and accumulated in a spatially limited region before being injected into an ion trap mass spectrometer such as a Fourier transform ion cyclotron resonance mass spectrometer (FTICR MS). In the ion trap electron capture dissociation (ECD) and vibrational excitation dissociation are sequentially applied on ions of the same ion ensemble. The first dissociation process does not fragment all primary ions. Following the detection of the dissociation products, the primary ions that remain undissociated undergo the vibrational excitation and again, a part of them dissociate, and the fragments are detected. Thus, the same ion ensemble is used for two fragmentation processes. During these processes, further ions generated in the external ion source are accumulated in the spatially limited region for subsequent analyses.

Abstract: In a TOF-MS according to the present invention, ions fly a round orbit or a reciprocal path once or more than once to be separated by their mass to charge ratios before they are detected by a detector, The detector is movable at least in two positions, where the effective distances from the exit of the round orbit or the reciprocal path to the detector are different. The length of time of flight of ions in each position of detector is measured, and the mass to charge ratio of an ion is calculated based on the difference of the lengths of time of flight in at least two positions. Similarly, the ion source may be movable at least in two positions, and a similar method can be used to calculate or estimate the mass to charge ratio of ions.

Abstract: A mass sensor, in an exemplary embodiment, includes a housing that includes a first plate, a second plate, and a center portion positioned between the first and second plates. The mass analyzer also includes an ionizer a double focusing mass spectrometer, and an ion detector. The ionizer, the double focusing mass spectrometer, and the ion detector are located in a cavity in the housing. The double focusing mass spectrometer includes an electric sector energy analyzer that includes a first element located on an inside surface of the first plate, and a second element located on an inside surface of the second plate. The first and second elements are substantially concentric and congruent and have a circular arc shape. Each first and second element include a first boundary electrode, a second boundary electrode, and a continuous resistive material extending between the first and second boundary electrodes.

Abstract: A spectrometer assembly comprising an ion detector array and a printed circuit board, wherein the ion detector array is attached on the printed circuit board, and the printed circuit board is secured on the same base plate that a magnetic section is secured. This configuration presents many advantages including, but not limited to, sturdy and convenient electrical connections between the assembly and following processing units, as well as mounting accuracy of the ion detector array in miscellaneous devices, and especially in front of magnetic sectors of spectrometers of the Mattauch and Herzog type. This invention pertains any types of ion detector arrays, with special emphasis to Strip Charge Detector Arrays, Faraday Cup Detector Arrays, and even more importantly to Shift Register Based Direct Ion Detection Chips.

Abstract: A negative ion source placed inside a negatively-charged high voltage electrode emits a beam which is accelerated to moderate energy, approximately 35,000 electron volts, and filtered by a momentum analyzer i.e. an analyzing bending magnet, to remove unwanted ions. Reference ions such as carbon-12 are deflected and measured in an off-axis Faraday cup. Ions of interest, such as carbon ions of mass 14, are accelerated through 300 kV to ground potential and passed through a gas stripper where the ions undergo charge exchange and molecular destruction. The desired isotope, carbon-14 along with fragments of the interfering molecular ions, emerge from the stripper into a momentum analyzer which removes undesirable isotope ions. The ions are further filtered by passing through an electrostatic spherical analyzer to remove ions which have undergone charge exchange. The ions remaining after the spherical analyzer are transmitted to a detector and counted.

Abstract: In one embodiment, a miniaturized structure and associated method function as a mass spectrometer or analyzer and may, with modification, function as an ion generator. The miniaturized structure has a pair of generally planar parallel spaced electrodes which have projecting walls cooperating to define an ion generating chamber and an exit aperture. By controlling the electric field which is oriented perpendicular to an applied magnetic field, the ion beam may be separated into a plurality beams based upon mass to charge ratio with a predetermined mass to charge ratio emerging from the exit of the apparatus and when the apparatus is functioning as a mass spectrometer or analyzer impinges on an ion collector which responsively transmits information to a cooperating processor. Where it is desired to have it function as an ionizer the ion collector disposed adjacent the ion exit is eliminated.

Abstract: A mass spectrometer having an ion optics system in a first vacuum region, which diverts ions travelling in a first direction from a source, characterized by an initial pressure, through an angle such that neutral particles and photons from the source continue in the first direction and are removed. The diverted ion beam is then directed into a quadrupole mass analyzer arrangement in a second vacuum region, which comprises a set of fringe electrodes followed by a linear mass analyzer and then an ion detector. The first vacuum region is characterized by a pressure intermediate the initial pressure and a second vacuum region pressure. The set of quadrupole fringe electrodes are configured to divert the ion beam prior to passage of the ion beam into the linear quadrupole mass analyzer and to shield the linear quadrupole mass analyzer entrance from a substantial portion of the trajectory of the ion beam in the first vacuum region.

Abstract: A mass spectrometer is described in which the ions are submitted to the action of a uniform adjustable electrical field {right arrow over (E)}1, within a set of plane parallel electrodes a1, . . . , ai, . . . an fitted with properly located slits for the ions transmission, and to the action of a uniform magnetic induction {right arrow over (B)}1. A reference system x,y is considered in a plane perpendicular to {right arrow over (B)}1, the axis x and y being respectively perpendicular and parallel to {right arrow over (E)}1, and the origin of the reference system being fixed at an average starting point of the ions. The crossed fields {right arrow over (E)}1,{right arrow over (B)}1, act together in an area where y<d and the magnetic induction {right arrow over (B)}1 acts alone in a further area where y>d, d being a distance separating the average starting point of the ions from the electrode &agr;n.

Abstract: A negative ion source placed inside a negatively-charged high voltage terminal emits a beam which is accelerated to moderate energy, approximately 35,000 electron volts, and filtered by a momentum analyzer i.e. an analyzing bending magnet, to remove unwanted ions. Reference ions such as carbon-12 are deflected and measured in an off-axis Faraday cup. Ions of interest, such as carbon ions of mass 14, are accelerated through 300 kV to ground potential and passed through a gas stripper where the ions undergo charge exchange and molecular destruction. The desired isotope, carbon-14 along with fragments of the interfering molecular ions, emerge from the stripper into a momentum analyzer which removes undesirable isotope ions. The ions are further filtered by passing through an electrostatic spherical analyzer to remove ions which have undergone charge exchange. The ions remaining after the spherical analyzer are transmitted to a detector and counted.

Abstract: Method and apparatus for modulating the direction and magnitude of the Casimir force between two bodies. In accordance with the illustrative embodiment, a repulsive Casimir force is generated by placing two bodies in near-proximity to one another. For one of the bodies, dielectric properties predominate; for the other, magnetic properties predominate. The arrangement further includes a device that alters the dielectric or magnetic properties of the bodies. By altering the dielectric or magnetic properties, the repulsive Casimir force can be made to decrease, then vanish, then reappear as an attractive force. Modulating the Casimir force in such a manner can be used to control stiction in MEMS devices and to accelerate particles, among many other applications.

Abstract: A new detection scheme for time-of-flight mass spectrometers is disclosed. This detection scheme allows extending the dynamic range of spectrometers operating with a counting, technique (TDC). The extended dynamic range is achieved by constructing a multiple anode detector wherein the individual anodes detect different fractions of the incoming particles. Different anode fractions are achieved by varying the size, physical location, and electrical/magnetic fields of the various anodes. An anode with a small anode fraction avoids saturation and allows an ion detector to render an accurate count of ions even for abundant species.

Abstract: A charged particle filter provides a curved through path and has both magnetic poles for applying a magnetic field normal to the plane of curvature of the path and electrodes for applying a radial electric field. The filter is used as an energy filter downstream of an accelerator in an ion implanter. The filter can be set to provide a range of energy dispersions, to operate as an achromatic bend, or to reject lower charge state ions.

Abstract: The present invention provides an instrument and methods for the preparative separation of components of mixtures using mass spectrometric methods. Nondestructive ionization methods are employed to generate ionized components of a mixture, the ionized components are spatially separated by mass and the mass-separated ion components are trapped. The ion source and mass spectrometric techniques employed allow the generation of large ion currents of ion components, on the order of nanoamps, which facilitate rapid accumulation of nanomole quantities of mass-separated components in relatively short times (minutes to hours).

Abstract: A charged particle beam method and apparatus use a primary electron beam to irradiate a specimen so as to induce the specimen to emit secondary and backscattered electrons carrying information about topographic and material structure of the specimen, respectively. The specimen may be an article to be inspected. The electrons emitted by the specimen are deflected in the electric field of an electron mirror and detected using an electron detector of the apparatus. The electron mirror permits the detection of the secondary electrons traveling close to the optical axis of the apparatus and corrects the aberrations of the secondary electrons. In addition, the electron mirror accelerates the electrons improving the detection efficiency of the electron detector and enhancing the time-of-flight dispersion characteristics of the secondary electron collection. A second electron mirror can be provided to further control the direction of the electron's landing on the surface of the electron detector.

Abstract: A mass spectrometer of the present invention is based on the use of quadrupole lenses with angular gradient of the electrostatic field. The device consists of an ion source connected to an ion mass separation chamber that contains a plurality of sequentially arranged electrostatic quadrupole lenses which generate a helical electrostatic field for sending ions along helical trajectories in a direct and return stroke. Scattering of positions of points of return is reduced by means of electrostatic mirrors located at the end of the direct stroke, while ions of different masses perform their return strokes along helical trajectories different from those of the direct strokes due to the use of a magnetic and/or electrostatic mirrors. An ion-electron emitting screen is installed on the path of ions in the reverse stroke, and positions of collision of the ions with the ion-electron emitting screen over time and space are detected with the use of micro-channel plate detectors.

Abstract: The analysis of isotopomers is conveniently performed using a double focusing high mass resolution magnetic mass spectrometer comprising an electric field and a magnetic field by a constant accelerating voltage slightly less than the accelerating voltage corresponding to the masses of the ions comprising the majority of a sample to be analyzed, and scanning part of an ion accelerating voltage so that it varies within a range effectively corresponding to the masses of the ions of isotopomers of the ions comprising the majority of the sample to be analyzed.

Abstract: A method and apparatus for accelerating and a decelerating particles based on particle surface interactions. In particular, in some embodiments, particles traveling away from a surface are made to travel at either a higher or lower speed than that with which they approached the surface. This change in velocity is effected by prompting the particles to undergo atomic transitions during their interaction with the surface.

Abstract: A mass sensor includes a magnet assembly and a mass analyzer. The mass analyzer includes a ceramic housing formed from two end plates and a center portion. The mass analyzer further includes a thermionic electron emitter ionizer, a double focusing mass spectrometer having superimposed orthogonal magnetic and electric fields, and a microchannel plate ion detector located in the housing cavity. The double focusing mass spectrometer includes an electric sector energy analyzer having a film resistor deposited on an inside surface of each end plate. The film resistors are substantially concentric and congruent and have a circular arc shape. Boundary electrodes are positioned adjacent each curved edge of each film resistor. The mass sensor includes a non-evaporable getter mounted inside the housing cavity and external electrical contacts arranged to form a multi-layer printed circuit card that is installable in a circuit card edge connector.

Abstract: An ion injecting apparatus has an ion source, a mass-analyzing magnet, an accelerating/decelerating element, and deflecting elements. The mass analyzing magnet mass-analyzes an ion beam extracted from the ion source. The accelerating/de-celerating element accelerates and decelerates the ion beam at a post-stage. The deflecting elements are arranged between the mass analyzing magnet and the accelerating/decelerating element. Each direction angle of the deflecting element is determined such that a final beam trajectory in the predetermined area before being introduced into a wafer substrate is matched to each other in both an operating mode and a non-operating mode of the deflecting elements.

Abstract: A combinatorial chemistry system allows for the dual processing of different molecules coated on a library of beads. The system includes beads coated with different molecules on each bead, a bead holder, screening equipment and characterization equipment. Molecules on the beads are both screened and characterized simultaneously.

Abstract: A mass spectrometer is described in which the ions are submitted to the action of a uniform adjustable electrical field {right arrow over (E)}1, within a set of plane parallel electrodes a1, . . . , ai, . . . an fitted with properly located slits for the ions transmission, and to the action of a uniform magnetic induction {right arrow over (B)}1. A reference system x,y is considered in a plane perpendicular to {right arrow over (B)}1, the axis x and y being respectively perpendicular and parallel to {right arrow over (E)}1, and the origin of the reference system being fixed at an average starting point of the ions. The crossed fields {right arrow over (E)}1,{right arrow over (B)}1, act together in an area where y<d and the magnetic induction {right arrow over (B)}1 acts alone in a further area where y>d, d being a distance separating the average starting point of the ions from the electrode &agr;n. The selection slit S1 is located at coordinates x=2.

Abstract: An ion-deflecting device is located between a mass spectrometer and a detector, and undesired signal sources are prevented from reaching the detector during the ion-trapping period by switching the voltage applied to the detector between the ion-trapping period and the mass-analyzing period. A first voltage is applied to the detector during an ion-trapping period while a second voltage is applied to the detector during a mass-analyzing period. An ion-deflecting device deflects ions such that they do not reach the detector during an ion-trapping period while they do reach the detector during a mass-analyzing period. This way, the life of the detector is increased.

Abstract: A method of monitoring particle beam current in an ion implanter in which the ion beam is analyzed to separate it into a separate sub-beam for each ion charge state. At least one sub-beam, having a charge state different from the desired charge state, is intercepted, and the current of the intercepted sub-beam is measured. This current is useful as an estimate of the current of the desired sub-beam which is used for the implantation.

Abstract: An apparatus and method for providing a low energy, high current ion beam for ion implantation applications are disclosed. The apparatus includes a mass analysis magnet mounted in a passageway along the path of an ion beam, a power source adapted to provide an electric field in the passageway, and a magnetic device adapted to provide a multi-cusped magnetic field in the passageway, which may include a plurality of magnets mounted along at least a portion of the passageway. The power source and the magnets may cooperatively interact to provide an electron cyclotron resonance (ECR) condition along at least a portion of the passageway. The multi-cusped magnetic field may be superimposed on the dipole field at a specified field strength in a region of the mass analyzer passageway to interact with an electric field of a known RF or microwave frequency for a given low energy ion beam.

Abstract: An electron energy analyzer integrated with a low-pass energy filter. The electron energy analyzer includes a separation region disposed inside a coil creating a magnetic field parallel to an axis of the separation region. The magnetic field is terminated at both ends of the separation region and shunted by a magnetic yoke around the outside of the coil. Electrons entering the separation region at a polar angle with respect to the axis accumulate an azimuthal angle dependent on the energy of the electron. Thereby, the direction the electron is traveling when it exits the separation angle depends upon its energy. According to the invention, a low-pass reflector is positioned at the input side of the analyzer, for example, a grounded grid in back of which is positioned a negatively biased absorption electrode. Electrons having energy exceeding the electrode bias are absorbed. Electrons having energy less than the electrode bias are reflected and exit the reflector with the same energy as before.

Abstract: A double-focusing mass spectrometer apparatus includes a first cylindrical sector electrode defined at a first radial distance from a axis with the first cylindrical sector electrode having an upper and lower edge and a second cylindrical sector electrode surface defined at a second radial distance from the axis with the second cylindrical sector electrode having an upper and lower edge corresponding to the upper and lower edge of the first cylindrical sector electrode. An ion path is defined between the first and second cylindrical sector electrodes. A first magnet pole and a second magnet pole are positioned proximate the upper and lower edges of the first and second cylindrical sector electrodes, respectively, for providing a magnetic field in the ion path. A first and second array of electrodes, e.g.

Abstract: A mass sensor includes a magnet assembly and a mass analyzer. The mass analyzer includes a ceramic housing formed from two end plates and a center portion. The mass analyzer further includes a thermionic electron emitter ionizer, a double focusing mass spectrometer having superimposed orthogonal magnetic and electric fields, and a microchannel plate ion detector located in the housing cavity. The double focusing mass spectrometer includes an electric sector energy analyzer having a film resistor deposited on an inside surface of each end plate. The film resistors are substantially concentric and congruent and have a circular arc shape. Boundary electrodes are positioned adjacent each curved edge of each film resistor. The mass sensor includes a non-evaporable getter mounted inside the housing cavity and external electrical contacts arranged to form a multi-layer printed circuit card that is installable in a circuit card edge connector.

Abstract: The invention comprises a mass spectrometer 1 and a method of mass spectrometry that is especially useful for the measurement of the isotopic composition of hydrogen in the presence of a helium carrier gas. Interference to the accurate measurement of the small HD+ peak at mass-to-charge ratio 3 by the much larger He+ peak at mass-to-charge ratio 4 is reduced by provision of an energy filter 35 in the ion detector assembly used to collect HD+ ions. This prevents ions of He+ which have lost energy through scattering, etc giving rise to a signal from the HD+ detector and distorting the deuterium hydrogen isotopic ratio measurement. Such a mass spectrometer 1 is typically used in conjunction with a continuous flow inlet system 4 based on an elemental analyzer that converts hydrogen present in a sample to gaseous hydrogen in a flow of helium carrier gas.

Abstract: A nuclear waste remediation system includes, in-line, an ionizer, an accelerator, an optional cooler and a separator. A pair of co-planar spaced-apart conductors extend the entire length of the system to establish a magnetic field which is perpendicular to the lengthwise dimension of the system. In the ionizer, the conductors are surrounded by casings which hold opposite alternating voltages that ionize a neutral gas. In turn, the ionized gas vaporizes nuclear waste to create a multi-species plasma. In the accelerator, cooler and separator, the conductors are surrounded by casings which carry the same dc current to thereby create an electric field which crosses with the magnetic field.

Abstract: A mass spectrometer is disclosed which yields fast, full-scan spectra over a wide mass-to-charge ratio range. The instrument contains an ion source which generates nearly monoenergetically-pulsed ion packets which spatially focus at a predetermined distance along the drift path of the ions, a mass filter/analyzer which linearly disperses or deflects the ions in the ion-packets by mass-to-charge ratio by applying a traverse, quadratically time-varying and increasing electric field over the entire length of the deflection region of the mass filter/analyzer, and a spatial mass detector. A method of analyzing the mass-to-charge ratio of ions is also disclosed.

Abstract: A small radii mass spectrometer that utilizes high energy density permanent magnets of greater than 10E7 GOe for focusing an ion trajectory. The ion optical path employs focusing of the parallel component of the beam emitted by the source such that the momentum selected beam is focused in 90.degree. geometry at or near the exit pole face. The width of the beam at the focal point is independent of the size of the beam exiting the ion source in first order but has a second order aberration term dependent on the source width and radius of curvature. The dominant terms in determining the collected beam width are the angular divergence of the source (which can be reduced by defining slit) and the energy spread of the ion beam. A second magnet may be used in tandem with the first magnet to cancel the second order aberration term and reduces the background created by ions scattering with residual gas molecules in the vacuum chamber.

Abstract: A mass spectrometer is provided having a plurality of analyzers and including at least one magnetic sector analyzer and, typically, an orthogonal-acceleration time-of-flight mass analyzer. Bypass means are provided so that by switching of the direction of the ion beam, the magnetic sector analyzer may be bypassed and the time-of-flight analyzer used either to analyse the beam of ions from the source or daughter ions produced by fragmentation of that beam.

Abstract: A mass spectrometer and methods for mass spectrometry which are useful in characterizing a plasma. This mass spectrometer for determining type and quantity of ions present in a plasma is simple, compact, and inexpensive. It accomplishes mass analysis in a single step, rather than the usual two-step process comprised of ion extraction followed by mass filtering. Ions are captured by a measuring element placed in a plasma and accelerated by a known applied voltage. Captured ions are bent into near-circular orbits by a magnetic field such that they strike a collector, producing an electric current. Ion orbits vary with applied voltage and proton mass ratio of the ions, so that ion species may be identified. Current flow provides an indication of quantity of ions striking the collector.

Abstract: This invention relates to the detection of the radioisiotope carbon-14 using Accelerator Mass Spectrometry (AMS). This invention has particular relevance to the fields of attomole level (10.sup.-18 molar) tracking of chemicals in biomedicine and the environment, the testing of new classes of medical drugs, the whereabouts of chemotherapy agents within cancer patients, the elimination of the need to store and dispose of low-level carbon-14 nuclear waste and neutron exposure monitoring around nuclear reactors.

Abstract: Purely electrical or magnetic deflection systems are usually utilized in the probe-shaping part of modern electron beam tomographs in order to remove the gas ions generated in the evacuated drift tube by electron impact from the beam. The known deflection systems, however, cause an offset of the electron beam, so that this enters extra-axially into the lens element following the deflection system. In the apparatus for removing ions from an electron beam disclosed herein, a deflection unit (Wien filter) generates an E.times.B field oriented perpendicular to the beam axis that exerts strong shearing forces only on the positively charged gas ions, but does not influence the electrons. The deflection unit is essentially composed of two tube electrodes lying at a constant potential, of an electrostatic octopole deflector, and two saddle coil pairs annularly surrounding the octopole deflector. The apparatus is useful for fast electron beam tomographs, including x-ray scanners.

Abstract: A generally circular mass spectrometer and ion filters used therein have hyperbolic pole pieces which can be machined by diamond turning. In a quadrature assembly, two pole segments can be identical and provide the outer arcuate pole surfaces, and two segments can be identical and provide the inner arcuate pole surfaces opposite from the outer pole surfaces. A support plate has an arcuate outer surface which engages alignment surfaces of the pole segments, the alignment surfaces and outer support surfaces being machined by turning. In a quadrapole, one outer pole piece and one inner pole piece are mounted on each support surface of the plate with the alignment surfaces in abutment with the support plate outer surface for accurate alignment. An outer pole segment on one support surface is electrically connected to an inner pole segment on the opposing support surface. Each support segment has a plurality of spokes for mounting to the support plate.

Abstract: A mass spectrometer includes an inductive coupled plasma source whose flame is near ground potential, an interface, a flight tube, and an analyzer that includes magnetic and electric sectors, and an ion detector, which detector is operated at high voltage for ion acceleration. The magnetic sector includes a magnet and pole pieces that are insulated electrically relative to the flight tube. The pressure within the interface preferably does not exceed 10.sup.-3 mbar. By varying the magnetic field and the acceleration potential, identification of a specified mass over defined time intervals is carried out. The disclosed mass spectrometer provides improved coupling between the plasma ion source and a double-focussing analyzer, while advantageously providing a low voltage regime for the plasma source.

Abstract: An apparatus employs two spaced apart dipole magnets. An ion beam containing carbon of mass 2, 13 and 14 is focused by an Einzel lens and is directed into a first dipole magnet. The first magnet causes the beam to bend approximately 70 degrees, which separates the mass 12, 13 and 14 ions while at the same time focusing them in the X direction or deflection plane. The ions exit the first dipole magnet and pass through a blanking plate which can selectively remove one or two of the beams of mass 12, 13 and 14 ions. After leaving the first bending magnet, the mass 12 and 14 beams pass through a steering device so the trajectories of the mass 12 and 14 ions are deflected a few degrees to bring them parallel to the mass 13 ion beam. The parallel ion beams next pass through an electrostatic slot lens which focuses the beams in the direction out of the bending plane. After passing through the slot lens, the mass 12 and 14 beams are deflected in like amount to the deflection at the first steering device.

Abstract: An electron energy analyzer uses identical sectors, typically though not necessarily ninety degree segments of a toroid, disposed in complementary relationship with an aperture therebetween to provide a mapping of the image at the entrance plane to the exit plane while permitting the desired energy analysis to be performed.

Abstract: This probe, which is to be placed in a uniform magnetic field, comprises an ion acceleration zone, a circular sector (6) polarized so as to create in the zone an accelerating electric field, an ion collector (8), a conducting grid (36) at the entrance to the zone for fixing the potential at said entrance, the distance between said grid and the sector being adequate to ensure that the ions drift into the zone from their incidence position on the grid. The sector has an entrance slit (38) displaced with respect to said incidence position in order that the electric field is uniform in the acceleration zone.

Abstract: In a mass spectrometer, an aperture defining a beam path to a particle detector (4) is defined by a fixed aperture (5) and a cover (6) mounted on respective carriage assemblies (50,49) running along a beam 46. When a shaft (36) drives carriage (50), a rod (22) on carriage (49) is engaged by an end of a slot (21) of carriage (50), so that both carriages can be moved to a desired aperture location. After reaching this position, carriage (50) may be moved in the opposite direction, within a range defined by the length of the slot (22), without causing movement of carriage (49), to vary the amount by which member (6) covers member (5) and to thereby define a desired aperture width. A plurality of carriages can be coupled to one another in this manner to form a chain of apertures whose positions and widths may be varied independently using a single drive shaft (36). The fixed aperture (5) and cover ( 6) may be replaced by a pair of opposed aperture-edge defining members in the same plane.

Abstract: An isotopic-ratio mass spectrometer comprises an r.f.

Abstract: A portable analytical grade mass spectrometer system contained in a single enclosure is disclosed for use in analyzing atmospheric, water, soil, drugs, explosives and other substances and includes a gas chromatograph and a mass analyzer assembly enclosed within a vacuum housing, a vacuum pump, and an on-board computer such that an operator, by means of an attached keyboard, can input data and information, and input a sample to be analyzed, and thereby operate the miniaturized mass spectrometer system.