Abstract: An electron generating apparatus for an ion source for example, which is capable of prolonging service life and facilitating the exchange of its filament has been proposed. The electron generating apparatus includes an electron generating chamber having a discharging gas supply hole and electron extracting hole, a pair of conductive filament support members mounted in the chamber through an insulating plate, and a filament detachably fixed on the filament support members. At least one of the filament support members is provided with an overhang to cover at least part of a region between the lower ends of the filament.

Abstract: A non-invasive apparatus for continuously measuring the cardiac output and cardio-respiratory function includes a gas sampling device which is inserted into the mouth of a human subject. The gas sampling device may be a disposable endotracheal tube or a smaller disposable mouthpiece. Each of these gas sampling devices is provided with a plurality of passages for sampling the lung gases and for continuously sampling the gas pressure on opposite sides of a capillary restriction member. A miniature motor pump mass spectrometer module is mounted on the upper end of the endotracheal tube or mouthpiece. Electronic circuitry connected to the mass spectrometer permits constant visual monitoring of the cardiac output and cardio-respiratory function.

Abstract: An electron beam excitation ion source comprises a housing having an ion generation chamber therein. A discharge gas and an accelerated electrons are introduced into the ion generation chamber, causing the accelerated electrons to collide against the discharge gas to generate a plasma containing ions in the ion generation chamber. The housing includes an ion extraction port through which the ions are extracted from the ion generation chamber outside the housing and an electron reflecting member exposed in the ion generation chamber to reflect the electrons.

Abstract: An ion source for creating an ion beam. The source includes an ionization chamber having one wall that defines a generally elliptical opening for allowing ions to exit the ionization chamber. Use of an elliptical (in section) ion beam has advantages over a rectangular ion beam which allow the integrity of a relatively high current ion beam to be maintained as ions travel to a beam treatment workstation. A dual configuration extraction electrode assembly also provides for a range of extraction energies from a single source.

Abstract: An ion cluster beam can be focused and delivered to a target with a selected energy range by directing the ionized beam through a beam crossover, and furnishing an energy-selecting apertured plate adjacent to the beam crossover so that the center of the beam passes through the aperture. The beam crossover is distributed along the beam axis due to the different energies of the particles in the beam. The apertured plate in the beam path removes from the beam those clusters having energies lower than and/or greater than an acceptable energy range, depending upon its placement and diameter, to provide energy selectivity. The portion of the beam passing through the aperture is imaged upon the target by a lens, and the beam may be deflected by deflector coils to write patterns across the surface of the target.

Abstract: A device for the injection of electrons into an electron tube, having: a superconductive bar, a first end of which enters the tube, and an electrical supply. The bar acts as a cathode. Two anodes, a main anode and a secondary anode are placed in the tube, respectively in the place where the electrons are collected and in the place where the first end of the bar enters. The electrical supply provides for application of two voltages, a main voltage and a secondary voltage. Electrons are accelerated along the bar through the two voltages and acquire a kinetic energy which is at least equal to the energy of extraction from the superconductor, and are thus ejected outside the bar.

Abstract: A large-area electron source which can operate continuously, stably, and indefinitely in a poor vacuum environment. The source includes a glow discharge cathode, appropriately positioned with respect to a target anode, and a fine-mesh grid spaced from the cathode by a distance less than the mean free path length of electrons leaving the cathode, the grid being electrically biased to control the electron beam current over a wide range with only small grid voltage changes. An accelerating voltage applied to the cathode can be varied continuously from as low as a few hundred volts to 30 KeV or greater and the source will continue to operate satisfactorily. Further, the grid is made of a fine mesh wire of sufficiently small dimensions as to not be resolvable in the target plane. A further refinement of the device utilizes scanning coils to achieve additional uniformity of the incident beam at the target plane.

Abstract: A tandem mass spectrometer includes an ion source, a first mass analyzer, a second mass analyzer, and a detector. An electron focusing source is provided between the first mass analyzer and the second mass analyzer in order to provide for dissociation of a parent ion beam into a plurality of daughter ion beams. In a first embodiment, the focused electron source comprises a cylindrical cathode having a concentric cylindrical anode in its interior. Control of the cathode temperature and the potential between the cathode and the anode provides a desired electron flux along the axis of the source. The second embodiment, the desired electron flux is provided by a field emission electrode.

Abstract: A plasma generator 10 which includes an rf driven cathode 40 capable of using reactive gases and having a cathode housing 54. A gas feed system 20 introduces gas into an antechamber 42 defined by the cathode housing 54. An electric field is generated within the antechamber 42 by an antenna 46. A grid 50 mounted within the antechamber 42 defines first R1 and second R2 regions therein, a first region R1 between the antenna 46 and the grid 50, and a second region R2. The grid 50 confines the electric field generated by the antenna 46 to the first region R1 of the antechamber 42 to induce a discharge of electrons from the gas therein. The grid 50 further allows at least a portion of the discharged electrons to migrate to the second region R2 to ionize the gas therein into a cathode plasma 60. In one embodiment, the plasma 60 is then induced to flow into a discharge chamber 70 defined by an anode shell 72.

Abstract: An electron/ion coincidence technique is employed to characterize the absolute mass dependent transmission efficiency of mass spectrometers. The technique is not dependent upon the partial pressure of the sample beam or the ionization cross sections of calibrant gases.

Abstract: Ion detection apparatus has an ionizer provided with an ionizer volume for receiving a specimen to be analyzed. An electron gun is operatively associated with the ionizer for bombarding the specimen with an electron beam and converting the specimen into ions. An analyzer receives the ions from the ionizer volume and includes a detector for detecting the ions. The electron gun has focusing means for varying the size and intensity of the electron beam. The electron gun may have an accelerating anode, a focusing collimator and a second anode. The ionizer means may have an extractor lens and collimating lens as well as a groundplate. The ionizer means may have an electron collecting plate for receiving electrons which pass through the ionizer volume and providing feedback regarding the electron beam.

Abstract: The invention provides a mass spectrometer comprising an ion source provided with an electron emitting source and magnets which are cooperable to produce a collimated electron beam within the ion source; a mass analyzer; first and second electrodes which cooperate to limit the angular divergence of the ion beam which emerges from the source along the ion beam axis; and magnetic field screens disposed between the first and second electrode means, which reduce the field due to the magnets along the ion beam axis. In this way the mass discrimination introduced by the magnets in prior ion sources is reduced and the accuracy of isotropic ratio measurements is improved.

Abstract: An ion thruster for accelerating positively charged ions produced by the collision of free electrons with gas atoms. An ion thruster (10,100) includes a cathode chamber (12, 60, 118) and an ionization chamber (14, 106). The outer surface of an emitter tube (28, 61, 128) is coated with a dielectric material to protect the emitter tube from sputtering erosion. A plurality of bar magnets (20, 22; 108, 110) are arranged in a spaced apart circular array around the cathode chamber with a pole face of each of the magnets tangentially aligned with wall sections (16, 18; 102, 104) of the ionization chamber. The bar magnets thus define a picket fence, wherein the magnetic field between adjacent bar magnets is used to extend the mean path of an electron entering the ionization chamber, improving the probability that it will impact an atom, creating an ion.A grid plate (112) comprises an accelerator grid (204) coated on its inner and outer surfaces with a dielectric coating (206, 208).

Abstract: An in-line reversal electron, high-current ionizer capable of focusing a beam of electrons to a reversal region and executing a reversal of said electrons, such that the electrons possess zero kinetic energy at the point of reversal, may be used to produce both negative and positive ions. A sample gas is introduced at the point of electron reversal for low energy electron-(sample gas) molecule attachment with high efficiency. The attachment process produces negative ions from the sample gas, which includes species present in trace (minute) amounts. These ions are extracted efficiently and directed to a mass analyzer where they may be detected and identified. The generation and detection of positive ions is accomplished in a similar fashion with minimal adjustment to potentials applied to the apparatus.

Abstract: An ion source comprising a discharge chamber that has a gas inlet and an ion exit, two pairs of cathodes that are disposed on the side surfaces of said discharge chamber, two pairs of anodes, each anode being disposed in a space between the adjacent cathodes, and a pair of solenoids that are wrapped around one pair of cathodes so as to be mutually repulsive magnetically, wherein there is no magnetic field in the central axis of the other pair of cathodes around which no solenoids are wrapped.

Abstract: An emitter produces a beam of electrons or ions accelerated at a relatively high accelerating voltage. The beam is sharply focused by a condenser lens at the final stage. An electrostatic field for retarding the beam is produced between the lens at the final stage and a target on which the beam impinges. The retarding field lowers the landing energy of the beam. An auxiliary electrode which is maintained at substantially the same potential as the target is disposed between the lens and the target. A secondary electron detector is mounted between the auxiliary electrode and the target.

Abstract: A method of effecting modifications at the surfaces of materials using low energy ion beams of known quantum state, purity, flux and energy. The ion beam is obtained by bombarding ion-generating molecules with electrons which are also at low energy. The electrons used to bombard the ion generating molecules are separated from the ions thus obtained and the ion beam is directed at the material surface to be modified. Depending on the type of ion generating molecules used, different ions can be obtained for different types of surface modifications such as oxidation and diamond film formation.

Abstract: An ion source of the side extraction type which includes auxiliary electrodes surrounding the cathode at the ends of the anode, and insulators surrounding the auxiliary electrodes and electrically isolating them from the anode. The auxiliary electrodes essentially define the ends of the discharge chamber, leaving the anode confined to the cylindrical surface surrounding the filament. Each insulator is made up of an inner insulator and an outer insulator with an annular space defined between them. The inner and outer insulators are each in the form of a cylinder with a radially extending flange formed at one end, and interfit with the anode and with each other such that cylindrical spaces are defined between the outer flange portion and the anode and between the inner and outer flange portions. These and other features contribute to improve the electrical isolation between the auxiliary electrode and the anode, prolong source life, and improve beam purity.

Abstract: A mass spectrometer (1) suitable for the analysis of the eluent of a liquid or supercritical fluid chromatograph is disclosed. In order to maximize the flow rate of fluid which can be accepted into its ionization chamber (13), aperture closing means (13) are provided between an electron or particle source (27) and an entrance aperture (40) into the ionization chamber through which electrons or particles enter the chamber when required to ionize the sample therein. The aperture closing means are operable to close said aperture when such ionization is not required, thereby increasing the maximum flow rate into the ionization chamber. Sample ionization may then be effected by means of a glow discharge in the chamber or by a liquid ionization process such as thermospray ionization.

Abstract: An apparatus for producing a beam of ionized clusters includes a source that emits a beam of clustered and unclustered atoms through a nozzle and a cold cathode ionizer that ionizes the clusters. The ionizer is positioned in close proximity to the nozzle and the beam as it is emitted from the nozzle. A plasma is formed in the beam adjacent the nozzle when secondary electrons emitted from the cathode are accelerated and injected into the beam, resulting in the ionization of atoms and clusters. The cathode is preferably formed, at least in part, of a material that efficiently emits secondary electrons when impacted by ionized atoms extracted from the plasma to impact against the cathode, and the secondary electrons are injected into the plasma to renew the process. The ionized clusters remain in the beam and proceed to their target.

Abstract: An electron cyclotron resonance ion source for an ion implanter. The source includes an ionization chamber surrounded along its length by an electromagnet. A number of extraction electrodes at an output end of the ionization chamber allow positively charged oxygen ions to pass through apertures in the electrodes. The uniformity of the axially aligned magnetic field in the ionization chamber is extended through the extraction electrode by a magnetically permeable electrode and through use of non-magnetically permeable material to mount others of said electrodes.

Abstract: Method of ionizing a gas within a chamber having a cathode disposed therein, wherein the sputtering effect upon the cathode is substantially reduced to prolong the life of the cathode. The cathode within the chamber is initially activated to emit thermal electrons by applying a voltage thereto. The gas to be ionized is then introduced into the chamber along with an active gas. Ionization of the gas to be ionized is then achieved by subjecting the gas to be ionized to the thermal electrodes emitted by the cathode. The voltage applied to the cathode and the voltage between the cathode and the wall of the chamber are regulated so as to maintain a substantially constant electric arc current flowing from the wall of the chamber to the cathode.

Abstract: An ion source including a plasma chamber for generating a plasma therein, at least three parallel electrodes for drawing out an ion beam from the plasma chamber, the first and second power sources for generating high and low drawing voltages, respectively, is disclosed in which the first power source is connected between the first pair of adjacent electrodes spaced apart from each other a relatively long distance to perform a high voltage operation, the second power source is connected between a second pair of adjacent electrodes spaced apart from each other a relatively short distance to perform a low voltage operation, and one of the high voltage operation and low voltage operation is changed over to the other with the aid of switching elements.

Abstract: The present invention provides an ion source comprising an ion-generating chamber and an anode formed of multi-capillary for sending high-density atoms or molecules to be ionized into the ion-generating chamber in a constant direction.

Abstract: A gas, ionizable to produce a plasma, is introduced into a region defined within an ion source. An anode is disposed near one end of that region, and a cathode is located near the other. A potential is impressed between the anode and the cathode to produce electrons which flow generally in a direction from the cathode toward the anode and bombard the gas to create a plasma. A magnetic field is established within the region in a manner such that the field strength decreases in the direction from the anode to the cathode. The direction of the field is generally between the anode and the cathode. The electrons are produced independently of any ion bombardment of the cathode, the magnet is located outside the region on the other side of the anode and the gas is introduced uniformly across the region.

Abstract: An ion source device comprises a plasma generating vessel for generating plasma therein, a plurality of magnets arranged on an outer periphery of the plasma generating vessel to establish a cusp field in the plasma generating vessel, means for supplying a power to generate the plasma in the plasma generating vessel, and an anode electrode arranged on an inner wall of the plasma generating vessel and adapted to be heated by electrons emitted from the plasma and maintain the heat.

Abstract: An improved ion source for characterization of a surface of a sample including a housing oriented about a central axis, Z; a magnet cooperatively disposed within the housing for producing a magnetic field along the Z axis direction an anode radially disposed within the housing and within the magnetic field of the magnet that defines an annular ionization chamber having an open annular space and further forming a central tubular space about the Z axis; a cathode cooperatively disposed at the anode and within the annular ionization chamber; an extractor grids means cooperatively disposed within the housing so as to form a boundary of the ionization chamber; annular focusing rings disposed on the housing and externally to the extractor grids for focusing ions emerging therefrom; neutralizer filament cooperatively disposed with focusing rings; a central lens cooperatively disposed about the central axis Z in the central tubular space formed by the anode and adapted to accept ions and neutrals emanating from a sam

Abstract: An ionizer for a quadrupole filter mass spectrometer has an ion volume ring which surrounds the filament and ionization chamber for 360.degree.. Heat from the filament is absorbed by the ring which suppresses secondary electron emission and directs electrons to the ionization chamber. The ion volume ring is in heat conducting relationship with accelerating and focusing electrodes to transfer heat to the electrodes to reduce contamination. The ion volume ring is electrically connected and is at the same potential as the filament.

Abstract: A gas chromatography plus mass spectrometer (GC/MS) system includes a gas chromatograph, a mass spectrometer, and a computer interface to both of them. The mass spectrometer includes an ion source with an electron emission filament which can be damaged if on during the time a solvent peak is eluting from the chromatography. The filament is regulated to provide a constant emission rate by feedback which causes a current source to compensate deviations from a desired emission level. When a solvent peak begins to elute, the concomitant sudden cooling of the filament is sensitively reflected in the feedback to the current source. a comparator AC-coupled to the current source input can be used in shutting off the current source when the emission current abruptly drops. A computer controller can reactivate the filament in response to a decrease in ambient pressure or elapse of a predetermined duration so that component peaks following the solvent peak can be analyzed.

Abstract: A compact, quick-igniting, and high-efficiency Penning-discharge type plasma source which comprises a cathode means for thermionically emitting electrons; an electron emission means disposed inside the cathode; anode means defining a discharge space, for accelerating electrons emitted by said cathode means and said emission means into the discharge space; means for supplying gas to be ionized to the discharge space; and heating means for initially heating the emission means. In a preferred embodiment, the anode means is a planar anode. Initial heating of the emission means by the heater causes electrons to be emitted therefrom. These electrons are accelerated by the planar anode to ionize the gas in the discharge space. An axial magnetic field with axial maximum near the exit aperture in the planar anode optimizes ionization and causes most of the plasma production to occur near the exit aperture, thereby enhancing efficiency of the source. Most of the ions produced exit the source before recombination.

Abstract: A high concentration of positive molecular ions of hydrogen or deuterium gas is extracted from a positive ion source having a short path length of extracted ions, relative to the mean free path of the gas molecules, to minimize the production of other ion species by collision between the positive ions and gas molecules. The ion source has arrays of permanent magnets to produce a multi-cusp magnetic field in regions remote from the plasma grid and the electron emitters, for largely confining the plasma to the space therebetween. The ion source has a chamber which is short in length, relative to its transverse dimensions, and the electron emitters are at an even shorter distance from the plasma grid, which contains one or more extraction apertures.

Abstract: The electron gun comprises an ionization chamber, adjacent to a high voltage chamber. In the wall common the both chambers provision is made for an extraction grid. On the opposite side, the ionization chamber comprises an outlet window for the electrons similar in shape to the extraction grid, and accompanied by a fine metallic foil. The high voltage chamber comprises a cathode brought to a high negative voltage. By giving the two grids the shape of similar parallel strips, a masking effect and a focusing effect are obtained at one and the same time which allows the efficiency of the electron gun to be increased.

Abstract: An ion source (10) of the side-extraction hot cathode type in which the inherent drift of electrons toward the positive side of the cathode is minimized by the addition of auxiliary electrodes (31, 32) which surround the cathode (14) at the ends of the anode (12). The electrodes are electrically isolated from the cathode and anode, and various means are provided to apply a potentials to the electrodes, including interconnecting the electrodes, cross-connecting the electrodes to opposite ends of the cathode, and biasing the electrodes at fixed potentials with respect to the cathode, anode or ground.

Abstract: An ion-producing apparatus comprises an electron-producing vessel having an electron-producing chamber, an ion-producing vessel having an ion-producing chamber communicating with the electron-producing chamber, a cathode provided at one end of the electron-producing vessel, an accelerating electrode provided within the ion-producing chamber, for allowing passage of electrons, an anode provided between the cathode and the accelerating electrode, and a power supply circuit for providing a potential difference between the cathode and the anode, thereby to produce electrons in the gap between the cathode and the anode. A vacuum pump is provided for evacuating gas from the ion-producing chamber. A partition is provided within the electron-producing vessel, between the cathode and the anode to divide the electron-producing vessel into a cathode-side chamber and an anode-side chamber, and hinders a gas flow from the cathode-side chamber to the anode-side chamber to apply a pressure difference between both chambers.

Abstract: A vacuum chamber (12) within which an instrument (22) to be calibrated or tested is placed, is fitted with an ion gun (14) having an ion source (48). The source (48) has an electron emitting filament (60) positioned adjacent one end of an ionization chamber (71), with a negatively biased grid (72) located behind the filament (60). Gas is injected into the source (48) by a gas flow regulator (54) in one end (52) of the source (48). The chamber (71) is surrounded by a plurality of independently energizable coils (82, 84, 86, 88, 90), with the last coil (90) being operated at the highest current level, thus producing the highest magnetic flux. This presents a region (160) of magnetic repulsion to the electrons produced by the filament (60) and causes them to be confined between the grid (72) and the region (160), greatly increasing the chances that an ionization collision will occur between the electrons and atoms of injected gas.

Abstract: Plasma generator which is constructed and operated to provide an enhanced probability of collisions between charged and neutral particles in the working chamber together with enhanced energy transfer and uniformity of the plasma. The plasma generator includes a chamber (1) with means to produce electrons (5) and to cause the electrons to rotate and spiral (6,7) to produce ion of gases introduced into the chamber to produce a plasma. The plasma is contained by magnetic mirrors (10,11) at each end of the chamber (2). Axial oscillation of the plasma is produced by a low frequency oscillating potential (9) in the chamber to significantly increased ion electron interaction.

Abstract: An ion beam for use in fabrication and processing of semiconductors, thin films or the like. For making uniform the radial distribution of an ion beam extracted from the ion source, a plasma chamber is formed by extending a plasma producing chamber in the direction in which microwave energy is introduced. The plasma chamber thus formed is provided with second magnetic means for generating a magnetic field of multicusp geometry.

Abstract: A thermal electron source suitable for use in an electron capture detector comprises a source of stable ultra-violet light, an ultra-violet transparent support member (20,31) located in the path of the ultra-violet light (41) and a thin photo-emissive metallic layer (1A, 24, 33) coated over the surface of the support member remote from the source. In one form the source is a cylindrical mercury vapor lamp (1) with the photo-emissive layer coated directly on the lamp. The coated lamp may then be enclosed within a cylindrical anode (8) with a gas flow between them and the electrical current is measured between the anode and cathode. In an alternative arrangement a planar geometrical assembly is provided. Preferably the photo-emissive material is gold and the carrier gas is an argon-methane mixture.

Abstract: In an ion beam source, the plasma is contained near the extraction front by a cup-shaped magnetic field for improved stability and uniformity. The intermediate electrode has a profiled electron beam aperture having a first narrowest section, a second slightly wider section, and the third, known, conical section. The anode electrode or anode insert has a very narrow entrance aperture followed by outwardly flared, longer, section.

Abstract: Apparatus which can be used for producing negative ions in a gaseous or liquid fluid is disclosed, as well as methods of using the apparatus to determine electron attachment parameters, to identify species in the fluid, or to separate selected species from the fluid. The apparatus comprises a photoelectron emitter, including a UV light source, which can be operated in pulsed or continuous modes, and a photocathode; in addition, a radially-spaced, coaxial negative ion collector, including a negative ion receiving plate, at least one of the photocathode and the receiving plate having cylindrical configuration.

Abstract: Apparatus and method for producing a stream (56) of a selected isotope. The apparatus comprises means for producing an atomic beam (26) containing the isotope of interest and other isotopes. Means (48) are provided for producing a magnetic field (28) traversing the path of the atomic beam of an intensity sufficient to broaden the energy domain of the various individual magnetic sublevels of the isotope of interest and having the atomic beam passing therethrough. A laser beam (32) is produced of a frequency and polarization selected to maximize the activation of only individual magnetic sublevels of the isotope of interest within the portion of its broadened energy domain most removed from other isotopes within the stream. The laser beam is directed so as to strike the atomic beam within the magnetic field and traverse the path of the atomic beam whereby only the isotope of interest is activated by the laser beam.

Abstract: An apparatus is disclosed for analyzing trace elements in a gas sample. A unique feedback system is provided for accurately regulating and sensing the pressure supplied to the ion chamber of the device. The feedback system is capable of compensating for a wide range of input gas pressures. The apparatus also includes an improved closed ion source which is resistant to corrosion and aids in the reduction of noise. In addition, a method is disclosed to calibrate the detector for accurately scaling the measurements of trace elements.

Abstract: A liquid metal ion source has a reservoir which holds a source material to-be-ionized in a melted state; an emitter which emits from its tip, ions of the melted source material fed from the reservoir; and an extracting electrode which applies a high electric field to the tip of the emitter, thereby to extract the ions from the tip of the emitter. The liquid metal ion source further comprises tank means for storing the source material to be fed to the reservoir, transfer means for transferring the source material from the tank means to the reservoir, and a vacuum chamber for holding the constituents in a vacuum state.

Abstract: A mass spectrometer of the type wherein a solenoidal magnet produces a magnetic field that includes a region along its geometric central axis. That region is a region of high field intensity and high homogeneity with magnetic flux lines in the region being generally parallel to the magnet central axis. A high vacuum is established in the region and a sample cell is positioned at or within the region in which sample ions are formed, trapped, excited and detected. An ionizing device is positioned outside of the region and off the central axis while an additional ionizing device may be positioned on the central axis. In a preferred embodiment, the off axis ionizing device may be supported for movement relative to the central axis. A preferred ionizing device for the off axis device is an electron gun.

Abstract: Negative ion source making it possible to produce an intense beam of negative ions, particularly of hydrogen and deuterium, as well as negative ions of other species. According to the main feature of this negative ion source, the number and distribution of the permanent magnets forming the magnetic multicusp confinement is chosen in such a way that the confinement time of the primary electrons is between 10.sup.-7 and 10.sup.-6 second and the thermionic electron emitters are located in the multicusp magnetic field between the saddle point of the magnetic field, formed by two adjacent permanent magnets and the center of the plasma in the vicinity of said saddle points. It is advantageously applied to the production of high-energy neutral atom beams used e.g. as an effective means for heating plasmas, produced in magnetic confinement fusion means.

Abstract: A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reeccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200.degree. to 500.degree. for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers.

Abstract: An electron gun is used with a mirror electrostatic field to produce zero or near zero velocity electrons by forming a turning point in their trajectories. A gas capable of attaching zero or near zero velocity is introduced at this turning point, and negative ions are produced by the attachment or dissociative attachment process. Operation may be continuous or pulsed. Ions thus formed are extracted by a simple lens system and suitable biasing of grids.

Abstract: An apparatus is described which makes possible the precise sputter etching and imaging of insulating and other targets, using a finely focused beam of ions produced from a liquid metal ion source. This apparatus produces and controls a submicron beam of ions to precisely sputter etch the target. A beam of electrons directed on the target neutralizes the charge created by the incident ion beam. Imaging of the target surface and ultra-precise control of the etching process is achieved by monitoring the particles that are sputtered from the target surface.

Abstract: An electron cyclotron resonance ion source in which a plasma is confined in a magnetic configuration having a first group of coils located in the plane defined by the tight window of an ultra-high frequency injector and surrounding the latter, supplying the magnetic field creating and confining a plasma as well as a second group of coils supplied in counter-field compared with the first group and surrounding an ion extraction system. Ion extraction takes place in a magnetic field well below that corresponding to the cyclotron resonance. This ion source has numerous applications in the field of thin layer sputtering, microetching, ion implantation, accelerators, etc.

Abstract: An ion source is disclosed in which a crucible for holding an ion source material is provided with an aperture in its bottom wall, an emitter chip is disposed within the crucible in a coaxial manner so that the edge of the emitter chip passes through the aperture, a semi-closed crucible made of a conductive material and having the form of a circular cone is disposed in the vicinity of the tip of the emitter chip so as to be coaxial with the emitter chip and to have the same electric potential as the emitter chip, a filament for emitting an electron beam is disposed in the vicinity of the emitter chip, an ion extracting electrode is disposed at a place which is a little spaced apart from the tip of the emitter chip, and a lid is inserted into the ion source material holding part so as to be placed on the above-mentioned semi-closed crucible, thereby preventing the ion source material from being scattered by evaporation.