Abstract: A mass spectrometer includes an ion source, an extraction device, a TOF mass analyzer, an ion trap mass analyzer, and an ion guiding optical element which guides at least one of extracted ions from the ion source and extracted ion fragments into the TOF mass analyzer in a normal mode of operation and into the IT mass analyzer in a tandem mode of operation. The apparatus operates by producing ions from a sample, extracting the ions from the ion source, selecting between the TOF mass analyzer and the IT mass analyzer, directing extracted ions to the selected mass analyzer, mass-separating the directed ions and fragments of the directed ions according to a mass-to-charge ratio, detecting mass-separated ions with the selected mass analyzer, and producing at least one of a normal mass spectrum and a tandem mass spectrum.

Abstract: A magnetic sector for charged particle beam transport that includes a magnetic field profile that achieves a linear dispersion from a collimated beam of charged particles proportional to their mass-energy-to-charge ratio. In one embodiment, the field profile necessary for the linear dispersion is obtained by the use of shaped, highly permeable poles powered by permanent magnets or electromagnetic coils.

Abstract: An apparatus for the separation of oppositely charged ions comprises a body including an inlet fluidly coupled to a first outlet and a second outlet. A flow director including a discharge is disposed in the body between the inlet and the first and second outlets. The flow director is configured to fluidly couple the inlet and the first and second outlets. The flow director discharge is proximate to the first and second outlets. A magnetic field is orthogonal to the flow director discharge and the magnetic field is located between the flow director and the first and second outlets. The magnetic field is configured to separate the oppositely charged ions.

Abstract: A hollow exciting current pathway in the form of conductor means is arranged outside of an ion deflection casing with a curved contour and having an inlet and an outlet. The conductor means is composed of a widthwise spiral formation of conductors running through the inlet and outlet and along the curved contour with a result that a magnetic field which is uniform widthwise is formed in the ion deflection casing. An ion beam is introduced through between the conductors at the inlet into the hollow exciting current pathway. By the action of the magnetic field through the hollow exciting current pathway, the ion beam is bent depending upon mass of ions; the ion beam with desired mass is taken out through between the conductors at the outlet with a result that the ion beam greater in size can be ion mass separated uniformly.

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: Apparatus and method for manipulating particles on a micro- or nano-scale. An embodiment of the present invention includes a magnetic micro-manipulation technique that utilizes micro-coils and soft magnetic microscopic wires for localized manipulation of particles. Another embodiment of the present invention uses magneto-static interaction between two magnetic microscopic wires to mechanically manipulate particles. Yet another embodiment of the present invention combines a magnetic particle with a magnetic manipulator or other device for generating magnetic fields to operate as a micro-fluidic micro-motor. Other embodiments of the present invention employ a magnetic separation system employing porous membranes partially filled with magnetic wires.

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: Incorporating the use of a permanent magnet within a GCIB apparatus to separate undesirable monomer ions from a gas cluster ion beam to facilitate improved processing of workpieces. In an alternate embodiment, the effect of the permanent magnet may be controlled by the use of an electrical coil. The above system eliminates problems related to power consumption and heat generation.

Abstract: A circular cycloidal mass spectrometer has an outer electrode of generally circular configuration and an inner electrode having a generally circular outer periphery with an annulus for the flow of ions defined therebetween. The electrodes are structured to create an electric field therebetween. A magnetic field generator is structured to create a magnetic field oriented generally perpendicular to said electric field. An ion beam source for injecting ions into the annulus for travel therearound is provided, and an ion exit for discharge of the ions traveling in said annulus is provided with an ion collector being disposed adjacent to the ion exit. The circular cycloidal mass spectrometer may be structured to provide, under the influence of the electric field and magnetic field, a path of travel for the ion beams, which is similar to either epicycloidal or hypocycloidal curves. If desired, elliptical shapes or other suitable shapes providing a nonlinear path of ion travel may be employed.

Abstract: When ions are introduced from outside into the ion trap space, a static electric field having equi-voltage surfaces concave to the entrance hole is formed in the ion trap space. For ions obliquely entering the ion trap space, such a static electric field makes the ions cross the equi-voltage surfaces at almost perpendicular angles. Owing to such configuration, ions are effectively decelerated, and enough time can be secured until ions of larger mass-to-charge ratios assuredly enter the ion trap space.

Abstract: A method of separating ions according to mass in a mass spectrometer includes establishing a stream of ions traveling in a generally cycloidal path in an electric field and a magnetic field, subsequently causing the electric field to terminate for a predetermined period of time while maintaining the magnetic field thereby causing the electrons to travel in a generally circular path for a predetermined time period and subsequently reestablishing the electric field to cause further travel in a cycloidal path and providing a detector for receipt of some of the ions. A suitably programmed microprocessor is employed to control operation of the mass spectrometer and to receive electrical signals responsive to ions impacting on the detector to thereby provide information regarding the ions. Corresponding apparatus is provided.

Abstract: A system for joining at least two beams of charged particles that includes directing a first beam along a first axis into a field. A second beam is directed along a second axis into the field. The first and second beams are turned, by interaction between the field and the first and second beams, into a third beam directed along a third axis.

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: 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: 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: A system for joining at least two beams of charged particles that includes directing a first beam along a first axis into a field. A second beam is directed along a second axis into the field. The first and second beams are turned, by interaction between the field and the first and second beams, into a third beam directed along a third axis.

Abstract: Methods and apparatus are provided for scanning a charged particle beam. The apparatus includes scan elements and a scan signal generator for generating scan signals for scanning the charged particle beam in a scan pattern having a scan origin. In one embodiment, the apparatus includes a position controller for positioning the scan elements based on a parameter of the charged particle beam, such as energy. The scan elements may be positioned to achieve a fixed position of the scan origin for different beam energies. In another embodiment, the apparatus includes first and second sets of scan elements and a scan signal controller for controlling the scan signals supplied to the sets of scan elements based on a parameter of the charged particle beam, such as energy.

Abstract: A “triggerless” arc initiation method and apparatus is based on simply switching the arc supply voltage to the electrodes (anode and cathode). Neither a mechanical trigger electrode nor a high voltage flashover from a trigger electrode is required. A conducting path between the anode and cathode is provided, which allows a hot spot to form at a location where the path connects to the cathode. While the conductive path is eroded by the cathode spot action, plasma deposition ensures the ongoing repair of the conducting path. Arc initiation is achieved by simply applying the relatively low voltage of the arc power supply, e.g. 500 V-1 kV, with the insulator between the anode and cathode coated with a conducting layer and the current at the layer-cathode interface concentrated at one or a few contact points. The local power density at these contact points is sufficient for plasma production and thus arc initiation.

Abstract: Cathodic arc plasmas are contaminated with macroparticles. A variety of magnetic plasma filters has been used with various success in removing the macroparticles from the plasma. An open-architecture, bent solenoid filter, with additional field coils at the filter entrance and exit, improves macroparticle filtering. In particular, a double-bent filter that is twisted out of plane forms a very compact and efficient filter. The coil turns further have a flat cross-section to promote macroparticle reflection out of the filter volume. An output conditioning system formed of an expander coil, a straightener coil, and a homogenizer, may be used with the magnetic filter for expanding the filtered plasma beam to cover a larger area of the target. A cathodic arc plasma deposition system using this filter can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

Abstract: The invention relates to a Wien filter provided with electrodes for generating an electric field, and magnetic poles for generating a magnetic field, said electrodes and magnetic poles being positioned around and having a finite length along a filter axis, and being positioned around the filter axis such that electric and magnetic forces induced by the respective fields and exerted on an electrically charged particle moving substantially along the fileter axis at a certain velocity, take substantially an opposite direction to one another and are directed substantially perpendicular to the particle's direction of movement through the filter, said filter having along its axis two ends determined by the finite length of the electrodes and magnetic poles, and said ends both being terminated by a closing plate which is positioned substantially transversely to the filter axis and is provided with an aperture around the filter axis to allow the particle to enter into an exit from the filter.

Abstract: A dynamic focus coil produces different selected ampere-turns while consuming constant power and therefore maintaining constant temperature. The focus coil comprises a set of coils that all consume the same power. A selected subset of coils (e.g. two or three) are energized at any given time, the subset being selected to produce the desired focus adjustment. Illustratively, the coils all have the same resistance and are driven by current having the same magnitude and selectable polarity. An alternative embodiment contains a “coarse” set of coils having selected values of ampere turns and a “fine” set of coils having values of ampere turns that fill in between the values of the coarse set.

Abstract: Temperature compensation for a magnetic sector used in mass spectrometry. A high temperature dependant magnetic sector is used. This magnetic sector is compensated by a magnetic shunt that has opposite temperature characteristics to those of the magnet.

Abstract: An electromagnet comprises a pair of magnetic pole 1a and 1b, a return yoke 3, exciting coils 4 and 5, etc. In an interior portion of a magnetic pole, plural spacers 2a-2g are provided putting side by side in a horizontal direction. Each of the spaces 2a-2g is an air layer and a longitudinal cross-section is a substantially rectangular shape and the space has a lengthily extending slit shape in a vertical direction against a paper face in FIG. 1. The plural spaces are mainly arranged toward a right side from a beam orbit center O and an interval formed between adjacent spaces is narrower toward the right side. The electromagnet having a simple magnetic pole structure and a wide effective magnetic field area in a case where a maximum magnetic field strength is increased can be secured.

Abstract: A method for measuring the end point and for monitoring the real time kinetics of a bioaffinity reaction in biological fluids and suspensions, employing microparticles as bioaffinity binding solid phase, biospecific reagent labelled with a fluorescent label and a fluorescence detection system which is based on two-photon fluorescence excitation, contacting the analyte, the labelled reagent and the solid phase simultaneously, focusing a two-photon exciting laser beam into the reaction suspension and measuring the fluorescence signal emitted by the microparticles from one particle at a time when they randomly float through the focal volume of the laser beam. In this method the signal is monitored kinetically to obtain information about the analyte concentration before the reaction approaches the highest point of the response. Since the growth rate of the signal intensity is directly proportional to the analyte concentration, the analyte concentration can be predicted in the initial phase of the reaction.

Abstract: The accelerator is a cyclic type accelerator having deflection electromagnets and four-pole electromagnets for making a charged particle beam circulate, a multi-pole electromagnet for generating a stability limit of resonance of betatron oscillation for the production of the charged particle beam, and a high frequency source for applying a high frequency electromagnetic field to the beam to move the beam to the outside of the stability limit, thus exciting resonance in the betatron oscillation. The high frequency source generates a sum signal of a plurality of AC signals of which the instantaneous frequencies change with respect to time, and of which the average values of the instantaneous frequencies with respect to time are different, and applies the sum signal via electrodes to the beam.

Abstract: A homogeneous biospecific assay method for an analyte in solution or in a biological suspension, in which a biospecific reagent competitively binding an analyte and a ligand labeled with a fluorescent molecule, is reacted with and bound to a solid phase, and in which the free labeled ligand is extracted is excited with two-photon excitation by focusing a laser beam suitable for two-photon excitation into the sample volume; and the concentration of the analyte is calculated based on the photon emission contributed by the free labeled ligand.

Abstract: Depending on the RF driving voltage amplitude value and the frequency of each frequency component of wideband auxiliary AC voltages, the wideband auxiliary AC voltage comprising plural different frequency components is optimized so that undesired ions having mass-to-charge ratios within the required range will be resonantly ejected from the ion trap electrodes.

Abstract: An ion beam generator includes an ion beam source for generating an ion beam, an acceleration/deceleration column for selectably accelerating or decelerating ions in the ion beam to desired energies, a source filter positioned between the ion beam source and the acceleration/deceleration column for removing first undesired species from the ion beam, and a mass analyzer positioned downstream of the acceleration/deceleration column for removing second undesired species from the ion beam. The ion beam generator supplies an energetic ion beam having a low level of energy and mass contaminants. The ion beam generator may be utilized in an ion implanter.

Abstract: An electromagnet comprises a pair of magnetic pole 1a and 1b, a return yoke 3, exciting coils 4 and 5, etc. In an interior portion of a magnetic pole, plural spacers 2a-2g are provided putting side by side in a horizontal direction. Each of the spaces 2a-2g is an air layer and a longitudinal cross-section is a substantially rectangular shape and the space has a lengthily extending slit shape in a vertical direction against a paper face in FIG. 1. The plural spaces are mainly arranged toward a right side from a beam orbit center O and an interval formed between adjacent spaces is narrower toward the right side. The electromagnet having a simple magnetic pole structure and a wide effective magnetic field area in a case where a maximum magnetic field strength is increased can be secured.

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: An electromagnet comprises a pair of magnetic pole 1a and 1b, a return yoke 3, exciting coils 4 and 5, etc. In an interior portion of a magnetic pole, plural spacers 2a-2g are provided putting side by side in a horizontal direction. Each of the spaces 2a-2g is an air layer and a longitudinal cross-section is a substantially rectangular shape and the space has a lengthily extending slit shape in a vertical direction against a paper face in FIG. 1. The plural spaces are mainly arranged toward a right side from a beam orbit center O and an interval formed between adjacent spaces is narrower toward the right side. The electromagnet having a simple magnetic pole structure and a wide effective magnetic field area in a case where a maximum magnetic field strength is increased can be secured.

Abstract: Improvements to reduce the size of a GCMS while improving its performance. A first improvement adjusts the magnet for radii of travel. Another feature removes a portion of the magnet to compensate for the fringe field. Yet another improvement shaves portions off of the yoke near where they meet the pole pieces.

Abstract: A system for separating certain ions from an ion beam in a mass spectrometer. A magnetic or electrostatic field is applied at an angle to the ion beam, causing the ions to disperse according to their mass to charge ratio. The ions are dispersed enough to allow certain ions to be blocked and removed from the beam using a physical stop. A subsequent plurality of fields is then applied to reform the beam and adjust its direction and dispersion.

Abstract: This invention provides methods and apparatus for continuously and efficiently separating the elements in a complex substance such as radioactive waste with a large volume plasma processor. One principal methods utilizes plasma confinement by toroidal magnetic fields with a poloidal divertor magnetic field and converts the plasma from a process plasma to a product plasma at a rapid rate permitting injection of a series of pellets, droplets or streams while the toroidal current in the plasma is maintained. A second principle method involves reducing the radiation losses in the separation process by eliminating the toroidal section and directly converting the feedstock material to a product plasma in an elongated evacuated container surrounded by magnetic field generating coils which produce magnetic fields that are parallel to the long axis of the evacuated container,The apparatus is a large volume plasma processor with multiple containment vessels.

Abstract: A low energy ion implanter having an ion source for emitting ions and an implantation chamber spaced from the ion source by an ion beam path through which ions move from the source to the implantation chamber. A mass analyzing magnet positioned along the beam path between the source and the implantation chamber deflects ions through controlled arcuate paths to filter ions from the beam while allowing certain other ions to enter the ion implantation chamber. The magnet includes multiple magnet pole pieces constructed from a ferromagnetic material and having inwardly facing pole surfaces that bound at least a portion of a ion deflection region. One or more current carrying coils set up dipole magnetic fields in the deflection region near the pole pieces. Additional coils help set up a quadrapole field in deflection region.

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 magnetic field type mass spectrometer having an ion source, an ion accelerator, a mass separation magnet forming an analyzing part which changes the trajectory of ions by a magnetic field of the mass separation magnet, and a current detector, wherein the mass separation magnet is installed so that ions move along a trajectory which turns several times in the analyzing part, and repelling electrodes are installed at turning points of the ions, whereby ions generated from the ion source are caused to move along a trajectory which turns several times in the analyzing part. Mass separation is carried out along each trajectory, which provides high resolution.

Abstract: This invention provides methods and apparatus for ionizing all the elements in a complex substance such as radioactive waste and for separation of some of the elements from the other elements. One principal methods utilizes plasma confinement by toroidal magnetic fields as a gate to regulate when and where specific elements are collected. While the plasma is confined, some of the species are removed by repeatedly cycling all of the species between the plasma and the deposition stages lining the walls, whereby some species preferentially accumulate on the deposition stages. The other species are then diverted into an additional containment vessel for collection or additional separations. The apparatus is a large volume plasma processor with multiple containment vessels. The invention provides for the characterization of waste material, and for its separation all within one serf contained vacuum environment. Other applications include remediation of chemical toxic wastes and chemical and germ warfare weapons.

Abstract: A low energy ion implanter having an ion source for emitting ions and an implantation chamber spaced from the ion source by an ion beam path through which ions move from the source to the implantation chamber. A mass analyzing magnet positioned along the beam path between the source and the implantation chamber deflects ions through controlled arcuate paths to filter ions from the beam while allowing certain other ions to enter the ion implantation chamber. The magnet includes multiple magnet pole pieces constructed from a ferromagnetic material and having inwardly facing pole surfaces that bound at least a portion of a ion deflection region. One or more current carrying coils set up dipole magnetic fields in the deflection region near the pole pieces. Additional coils help set up a quadrapole field in deflection region.

Abstract: A mass recombinator comprises a source of negative ions to be analyzed. These negative ions are accelerated to roughly the same moderate kinetic energy and electrostatically focused to a substantially parallel beam which enters the magnetic field of a dipole magnet at an angle of incidence. The field of the dipole magnet is designed to deflect a substantially parallel beam of negative ions having the same energy and entering at a specified angle of incidence in such a manner that it describes a loop of approximately 264.6 degrees, forming a mass spectrum at a position inside the magnet after deflection of approximately 132.3 degrees. The beam exits the field as a parallel beam substantially where it entered, independent of the mass of the ions.

Abstract: A multiple charged-particle detector system includes a plurality of charged-particle detector assemblies (10-12) which are each made up of a first arm (19-22) and a second arm (24-27) extending at an angle to each other. Charged particles (4-7) enter an aperture (14-18) at the entrance of the first arm (19-22) of each detector assembly (10-12) and strike a dynode (30-33) positioned at the intersection of the two arms causing electrons to be emitted by the dynode (30-33). Some of the electrons pass into the second arms (24-27) of the detector assemblies (10-12) and are detected by a continuous-dynode electron multiplier (35-38). The first arms (19-22) are narrower than the detectors (35-38), and the detector assemblies (10-12) are arranged in such a way that the minimum separation at which charged-particle beams (4-7) can be detected is determined by the widths of the said first arms (19-22) of the detector assemblies (10-12), and not by the widths of the detectors (35-38) themselves.

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: Compact and economical apparatus for use in accelerator mass spectrometry for mass selection and attenuation of each isotope by a predetermined fraction that is necessary to permit isotope sequencing through the accelerator stage, by a rotating shutter whose attenuation characteristics are defined by its mechanical shape.

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 magnetic sector for a non-scanning mass spectrometer includes a high permeability yoke with opposing faces to which are attached high energy product magnets and shaped pole pieces separated by a gap so that a high magnetic flux exists in the gap. The high magnetic flux in the gap enables very small surface areas of the pole pices faces forming the gap so that the overall magetic sector volume and weight are reduced.

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.

Abstract: The partial pressure gauge consists of a combination of a magnetically confined cold-cathode discharge for the ionization of the residual gas in a vacuum system (ion source) and the magnetic separation of the ion masses (mass spectrometer). A suitable inhomogenous magnetic field configuration is instrumental in producing such a discharge that the energy spread of the ions is sufficiently small, which in turn guarantees the resolution required for mass separation in partial pressure measurements (for purposes of leak detection). The ions are accelerated solely within the electric field of the discharge. The special shape of the cold-cathode discharge influences the electric field in such a manner that the energy of the emitted ions is low and remains virtually independent of the potential applied to sustain the discharge. Due to the low ion energy a moderate magnetic field suffices for the mass separation.

Abstract: A quadrupole mass spectrometer (QMS) system having an ion source, quadrupole mass filter, and ion collector/recorder system. A weak, transverse magnetic field and an electron collector are disposed between the quadrupole and ion collector. When operated in negative ion mode, the ion source produces a beam of primarily negatively-charged particles from a sample, including electrons as well as ions. The beam passes through the quadrupole and enters the magnetic field, where the electrons are deflected away from the beam path to the electron collector. The negative ions pass undeflected to the ion collector where they are detected and recorded as a mass spectrum.