Abstract: The capability of an existing AMS system is expanded to provide capability for identification of .sup.36 Cl atoms to the exclusion of .sup.36 S atoms by adding to such a system a booster accelerator having an ionization detector in its high-voltage terminal capable of measuring dE/dx as a function of penetration depth. The voltage of the direct-voltage accelerators employed need not exceed voltages of the order of 3 million volts, even though the ions detected have energies in excess of 36 million electron volts.

Abstract: The invention typically provides a double focusing mass spectrometer comprising an ion source (55), an ion momentum analyzer (56), a multichannel detector (58) and a multielectrode electrostatic ion-energy analyzer (57), wherein the energy dispersing field is generated by arrays of electrodes disposed in groups above and below the ion beam. By appropriate selection of the potentials applied to the electrodes, the focusing properties of the analyzer can be changed, allowing different extents of the mass spectrum to be accurately focused on the face of the detector (58) as it is tilted by the actuator (61) at different angles to the ion beam (64) emerging from the analyzer (57). This enables the spectrometer to simultaneously record either a small part of a mass spectrum at high resolution or a larger part at a lower resolution. Alternative arrangements of the detector which allow a similar result to be obtained are also disclosed.

Abstract: An electrostatic analyzer (1) for dispersing a beam of charged particles (10) according to their energy comprises two groups (2, 3) of spaced-apart linear electrodes (4, 8, 9, 20) respectively disposed above and below the charged particle beam. The potentials of the electrodes (4, 8, 9, 20) in each group progressively increase from one to the next, thereby providing an electrostatic field in a central plane (7) between the groups which is capable of deflecting the charged particles along different curved trajectories (11, 12) according to their energies. Various mass spectrometers incorporating such an analyzer are also disclosed.

Abstract: Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and .sup.3 He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions.

Abstract: An ion source for producing wide, large area type ion beams with a mass-separation device. Four, five six or so electrode plates with ion holes at the same positions are installed at the outlet of the ion source. Second or third one of the electrodes has Wien filters at the ion holes. The Wien filter has permanent magnets and electrodes for producing a magnetic field and an electric field perpendicular to the axial direction of the ion holes. Ion beams which have not been accelerated so fast are separated by mass by the Wien filter. Low kinetic energy of ions alleviates the strength of the magnetic field and the electric field. Wide, large area type ion beams without impurities are obtained.

Abstract: The disclosed mass spectrometer has, positioned between an input slit and an output slit, crossed by particles emitted by a sample, an optical coupling system placed between two respectively electrostatic and magnetic sectors. The optical coupling system comprises at least two lenses with slits oriented respectively along a first direction in which the path of the ions is incurvated by the electrostatic and magnetic sectors and along a direction perpendicular to the plane of the path. The position of the two lenses on the optical axis of the spectrometer is determined to obtain a compensation for the chromatic dispersions throughout the axis downline from the spectrometer, a stigmatic image of the input slit in the output plane of the spectrometer and a stigmatic image downline from the spectrometer.

Abstract: A mass spectrometer comprising ion source means (1) for producing ions characteristic of a sample to be analysed; ion detector means (14) for receiving at least some of said ions; magnetic sector analyzing means (18) and electrostatic analyzing means (8) disposed in any order between said ion source means (1) and said ion detector means (14); wherein said magnetic sector analyzing means (18) comprises means for dispersing ions according to their mass-to-charge ratios and for transmitting ions whose mass-to-charge ratios lie within a predetermined range and have a first kinetic energy; said electrostatic analyzing means (8) comprises means for generating an electrostatic field for deflecting ions having different kinetic energies around different curved trajectories such that ions having a second kinetic energy, lower than said first kinetic energy, are deflected around a central curved trajectory (15) and transmitted through said electrostatic analyzing means (8), and the strength of said electrostatic field

Abstract: An arrangement is described for extracting charged particles which have been emitted from a sample due to the impact of a primary ion beam. The arrangement comprises an electrode arrangement effective to produce an electric potential which is non-linear along a chosen direction of travel of the particles. A system of einzel lenses is effective to match the trajectories of the particles passing from the electrode means to the analyser of a mass spectrometer.

Abstract: A method of mass spectrometry and a mass spectrometer for the analysis of a sample, the mass spectrometer comprising means for producing ions from the sample and a magnetic sector for analyzing the ions, wherein the magnetic field of the magnetic sector is generated by passage of a magnet current controlled by a digital control signal representative of a sequence of integers generated by a computer. According to the invention, means are provided for generating the magnet current in exponential relation to the sequence of integers. In contrast to prior spectrometers, the invention provides peak switching and mass selection across the mass range with a constant number of integer steps per mass peak, thereby facilitating the digital selection of any particular mass peak, particularly those at low mass.

Abstract: A portable mass spectrometer is described having one or more electrostatic focusing sectors and a magnetic focusing sector, all of which are positioned inside a vacuum chamber, and all of which may be adjusted via adjustment means accessible from outside the vacuum chamber. Mounting of the magnetic sector entirely within the vacuum chamber permits smaller magnets to be used, thus permitting reductions in both weight and bulk.

Abstract: The invention relates to a variable dispersion double-focusing mass spectrometer comprising at least a magnetic sector analyzer (4) preceding an electrostatic analyzer (6), which analyzers cooperate to form a direction and velocity focused image on a multichannel detector (34) locatable in a focal plane of the electrostatic analyzer (6). The geometrical parameters of the electrostatic analyzer are selected so that the magnification of the electrostatic analyzer is substantially zero, which makes it possible to use a variable radius electrostatic analyzer to vary the extent of the mass spectrum imaged on the detector (34) while still maintaining double focusing. A variable radius electrostatic analyzer suitable for use in the invention is also described.

Abstract: A time-of-flight analyzer, such as a secondary ion surface analyzer, and method are disclosed wherein a beam of charged particles is created, magnified, directed along a path to a detector, detected and the time of flight measured. An emission lens is positioned on the path to produce the magnification and an additional lens can be provided along the path to produce variable magnification. A field aperture along the path limits the size of the image and a contrast diaphragm limits the lateral ion velocity. Two or more, preferably three, particle steering analyzers are sequentially positioned along the path from the emission lens to the detector with each of the three analyzers steering the particles through substantially 90 degrees.

Abstract: An energy selecting filter comprising a structure of four hemispheres to be transpassed successively by a beam of charged particles to be filtered. The structure is symmetrically with respect to a plane of symmetry in which the energy selecting element, such as slit or a knife-edge is introduced. In a charged particle beam apparatus such as a high resolution electron microscope the energy spread introduced by a source can adjustable be reduced to below for example 0,1 eV without introducing any beam deviation at the cost of only a small lengthening of the apparatus.

Abstract: A magnetic mass spectrometer having a one or two-dimensional ion detector for simultaneously detecting all ions focused and separated by the magnetic field. An electrostatic or magnetic octupole lens producing an octupole field is disposed in the ion path between the magnetic field and the detector.

Abstract: There is disclosed a mass spectrometer which is equipped with a simultaneous detection-type ion detector including a microchannel plate but provides improved sensitivity. The spectrometer has an ion source, a mass analyzer for dispersing and focusing the ions introduced from the source according to their mass-to-charge ratios, three electrodes each taking the form of a flat plate, as well as the detector. The electrodes are disposed on the ion path between the mass analyzer and the detector. The electrodes produce a focusing action not in the direction in which the ions are dispersed according to their mass-to-charge ratios but in the direction perpendicular to that direction. The electrodes are spaced from each other in the direction in which the ions travel. Each electrode is provided with a rectangular hole to pass the ions. The dimension of this hole taken in the direction in which the ions are dispersed is sufficiently longer than the dimension taken in the direction perpendicular to that direction.

Abstract: There is disclosed a double-focusing mass spectrometer in which ions are generated from a sample in a microwave-induced or inductively-coupled plasma (3). Ions are sampled from the plasma (3) through an aperture in a sampling cone (19) and pass through a skimmer cone (28) and several electrostatic lenses (30,33) to the entrance slit of the mass analyzer. The sampling cone (19) and skimmer cone (28) are maintained by a power supply (40) at a potential approximately equal to the accelerating potential required by the mass analyzer. It is found that the plasma potential may be maintained at such a value that a substantial proportion of the ions generated in the plasma (3) have energies lying within the energy passband of the mass analyzer, so that a high sensitivity, high resolution mass spectrometer especially suitable for the elemental analysis of solid or liquid samples is provided.

Abstract: In isotope mass spectrometry, there is the problem that in the case of very great frequency differences, the less frequent masses are swamped by the more frequent masses in the measurement result or that the corresponding measurement result is falsified. A correction device is proposed, which comprises a quadrupole mass filter with a voltage supply device which is controlled by the ion separation system and is designed in such a manner that the supply voltages of the quadrupole mass filter and thus its characteristic with respect to the mass quantity to be allowed through are switched over synchronously with the varying mass deflection setting of the ion separation system.

Abstract: The invention comprises of four magnet system for dispersing and recombining precisely several isotopes for injection into a tandem accelerator. The precise horizontal focusing of the ions is achieved magnetically using curved boundaries of the magnets which have normal entrance and exit boundaries for the central trajectories. The precise vertical focusing is achieved mainly by the electric slot lenses in the first version, with small adjustments of the focusing of the isotopes, other than the central trajectory isotope, by curved boundaries of the magnet. It is the use of the electric slot lenses, or a similar electric device with one dimensional focusing, which in part decouples the focusing action in the vertical plane from the horizontal plane, that permits the use of four fold magnetic symmetry and boundary curvature to accomplish true recombination of the isotopes in a practical and compact device.

Abstract: A method of detecting the amount of C-14 in a sample, comprising the following steps:ionizing the sample to form a negative-ion beam; deflecting said beam in a magnetic field and directing the deflected beam through a first acceptance aperture to remove all negative ions except mass-14 particles; accelerating said mass-14 negative ions to an energy E of the order of 10 MeV by a high voltage electrostatic field; stripping three electrons from a majority of said negative ions to form doubly-charged positive ions; deflecting said doubly-charged positive ions in an electrostatic deflecting field through 180.degree. and directing the deflected beam through a second acceptance aperture to remove particles in other than the 2.sup.

Abstract: A double focusing mass spectrometer is used as the second mass analyzer of a Mass Spectrometry/Mass Spectrometry Instrument comprising a uniform electric field and a magnetic sector. Fragment ions produced from precursor ions of a certain ionic species are introduced into a uniform electric field. The fragment ions travel along parabolic orbits and are separated according to their respective energy levels. The separated fragment ions are introduced into a magnetic sector and are dispersed according to their mass by the magnetic sector. A two-dimensional ion detector is disposed along a focal plane of the magnetic sector in order to simultaneously detect the fragment ions and to obtain a spectrum of the fragment ions.

Abstract: There is disclosed a direct imaging type SIMS (secondary ion mass spectrometry) instrument having a mass analyzer comprising superimposed fields. The superimposed fields consist of a toroidal electric field and a uniform magnetic field substantially perpendicular to the electric field. In an imaging mode, and ion image of the region of a sample which is irradiated with a primary beam is focused onto a two-dimensional ion detector by the mass analyzer having the superimposed fields. In TOF (time-of-flight) mass spectrometric mode, the intensity of the magnetic field of the superimposed fields is reduced down to zero to use only the electric field. Pulsed secondary ions from the surface of the sample are passed through the electric field and are separated according to mass with the lapse of time on the principle of TOF mass spectrometry.

Abstract: The invention relates to a double focusing mass spectrometer with a combination of an electric and of a magnetic field for directional and velocity focusing. In order to provide a compact and constructionally simple arrangement, it is proposed that a common magnet is used for the Wien filter (10) and the sector magnet (11). Preferably, this double focusing mass spectrometer is used in an MS/MS arrangement.

Abstract: There is disclosed a direct imaging type SIMS (secondary ion mass spectrometry) instrument having a mass analyzer comprising superimposed fields. The superimposed fields consist of a toroidal electric field and a uniform magnetic field substantially perpendicular to the electric field. In said electric field, the central orbit of the ion beam is located in an equipotential plane. The mass analyzer causes an image of the region on the sample bombarded with a primary beam to be focused onto a two-dimensional detector to form a mass-filtered ion image. The SIMS instrument can operate in a mode where only the intensity of the magnetic field of the mass analyzer is set equal to zero. In this mode, only ions having a selected energy within a certain energy bandwidth produce an image, that is, an energy-filtered ion image is formed.

Abstract: A double-focusing mass spectrometer comprising a Wien filter and a homogeneous magnetic field. Daughter ions produced from parent ions of a certain ionic species differ in mass but have velocities substantially equal to that of the parent ions. The Wien filter is set up such that the velocities of the daughter ions satisfy the Wien condition. Thus, the daughter ions originated from the specified parent ions pass through the filter and are dispersed according to mass by the homogeneous magnetic field and focused into a focal plane. A two-dimensional ion detector is disposed along this focal plane in order to simultaneously detect said daughter ions and to obtain a spectrum of the daughter ions.

Abstract: An apparatus is provided for use in determining the components of an inputted gas mixture. The apparatus includes a single piece body or framework preferably made of a high insulating material, such as ceramic. The body includes a number of cut-outs for receiving or incorporating hardware used in generating ions, controlling their movement, and directing them to an ion collector plate. One of the cut-outs formed in the insulating body receives an ion source assembly. Another of the cutouts is a passageway with metallized material coated along the walls thereof for use in generating an electric field. A third cut-out receives and is associated with a magnet assembly used in directing ion movement towards the collector plate. The single body and cut-out construction reduces the number of individual parts, improves the assembly of such parts and reduces adjustment time associated with such parts.

Abstract: A compact double-focussing mass spectrometer comprises, in the order named long an ion beam path, an einzel lens for focussing ions entering through an entrance slit into an exit slit and for effecting angle focussing, further a magnetic deflection field and an electric sector field each having a deflection angle of 30 degrees and opposite directions of deflection and in combination effecting energy focussing. Since the deflection angles of the magnetic and electric fields are relatively small and have opposite directions, the net ion beam path is essentially straight, and therefore the mass spectrometer can be implemented by a compact structure.

Abstract: An ion implantation apparatus which is suited for manufacturing semiconductor devices and which is particularly suited for implanting double charged ions into the wafers 22. Ions of a predetermined mass only are selected by a mass-separating electromagnet 14 from an ion beam 12 that is emitted from an ion source 10, and are implanted into the wafer 22 via a slit 16. Between the slit 16 and the mass-separating electromagnet, there are provided field electrodes 24 having a direction of deflection which is the same as that of the mass-separating electromagnet 14 to separate ions having different energy levels, and deflection magnets 26 having a direction of deflection at right angles with the direction of deflection of the mass-separating electromagnet. The slit 16 is arranged so that undeflected neutral particles and low energy ions deflected by the field electrodes 24 will pass through the slit while high energy ions will be deflected the proper amount to pass through the slit.

Abstract: A surface analyzer for analyzing physical properties of the surface of a sample by means of PELS (Proton energy loss spectroscopy) in which accelerated ion beams such as proton beams impinge on the sample in the vertical direction to the surface of the sample and ion beams scattered from the sample are decelerated and then detected by an analyzer to analyze the energy loss of the ion beams. The surface analyzer comprises an ion beam source for generating ion beams, deflecting means for deflecting the ion beams from the ion beam source, irradiating the surface of the sample with the ion beams from the ion beam source in the vertical direction to the surface of the sample, and deflecting scattered ion beams from the sample, accelerating and decelerating means for accelerating the ion beams before the ion beams impinge on the sample and decelerating the scattered ion beams, and analyzing means for detecting the scattered beams and analyzing energy loss of the ion beams.

Abstract: In a mass analyzer, an acceleration voltage is applied to an ionization chamber in which a voltage to be applied to repeller electrodes to repel ions is generated with reference to the acceleration voltage and a repeller voltage source is linked with a controller by use of a photocoupler or the like such that the repeller voltage is adjusted with the repeller voltage source electrically insulated from the controller. The repeller voltage can be easily and automatically adjusted by use of a low-voltage control signal so as to obtain a sensitivity developing the maximum value of the quantity of detected ions and hence a qualitative or quantitative analysis of a sample can be achieved with a high sensitivity. The controller processes digital signals and appropriate parameters are stored in a memory. Each parameter is changed with the center of change set to an appropriate parameter previously used and consequently the automatic control is simplified.

Abstract: A Wien filter for use in charged particle beam systems is disclosed, having two opposed resistive magnetic pole pieces separated from a set of excitation coils by an electrically insulating material. Two opposed electric pole pieces are positioned in orthogonal relationship to and in physical contact with the magnetic pole pieces to form a physical aperture through which the charged particles will pass. The resistivity of the magnetic pole pieces is such that sufficient current will flow through them between the electric pole pieces to establish a uniform electric field over the entire physical aperture.

Abstract: A lens arrangement (30) for the focusing of a beam of electrically charged particles (24) in the beam path of imaging systems, more particularly in mass spectrometers (10), is indicated, the lens arrangement (30) being connected to an electrical voltage supply. The lens arrangement (30) is situated at the location or in the vicinity of the intermediate image (29) produced by the imaging system, and consists of a plurality of plates (32 to 35) disposed in succession, with aligned transmission apertures (38 to 41), the plates being connected to adjustable electrical voltages.

Abstract: There is provided a mass spectrometer having at least three analyser sectors of the electrostatic or magnetic types, at least one sector being of the electrostatic type and at least one further sector being of the magnetic type. The spectrometer includes a focusing sector array having at least three analyzer sectors, the sectors of the array being dimensioned and positioned so as to cooperate to form a velocity- and direction- focused image. The sectors of the array are dimensioned and positioned as to form no velocity focused image within the array. One sector of said array is disposed adjacent to and between two sectors of the other type.

Abstract: When AC voltages in-phase to each other are superposed on the DC voltages applied to a pair of opposing electrodes of a quadrupole lens, the waveform of the intensity of the ion beam is disturbed only if the central orbit of ions is deviated from the center of the quadrupole lens. In view of this, adjustment of the central orbit of ions is facilitated with the help of variations in the waveform of the intensity of the ion beam while superposing the AC voltages in-phase to each other on the DC voltages applied thereto.

Abstract: Mass spectrometer having an ion source, acceleration means able to impart to the ions an energy essentially dependent on their electric charge, means for producing in a sector a magnetic field orthogonal to the plane of the trajectory of the ions in order to inwardly curve said trajectory and means for detecting the ions. At the inlet of the magnetic sector are provided electrostatic means able to modify the tangential velocity of the ions and consequently their energy, in such a way that ions with different masses can, at different times, follow the same inwardly curved trajectory in the magnetic sector.

Abstract: Detection of unknown daughter ions using a mass spectrometer in which two mass spectrometric units are coupled together. The spectrometric unit in the front stage has either an electric field or superimposed fields. The spectrometric unit in the rear stage has superimposed fields. The voltage Vdx.sub.2 necessary to produce the electric field in the front stage and the voltage Vdx.sub.1 necessary to produce the electric field of the superimposed fields in the rear stage when daughter ions having known mass and energy are detected are found. Further, the voltage Vdx.sub.2 ' necessary to produce the electric field in the front stage and the voltage Vdx.sub.1 ' necessary to produce the electric field of the superimposed fields in the rear stage when unknown ions are detected are found. Both the mass and the energy of the unknown ions can be determined from these four voltages.

Abstract: A mass spectrograph combining one or more magnetic deflections with the action of electrostatic fields, characterized by the fact that the system is circularly symmetrical; by the fact that the ions are injected radially from a source constituted by a heated circular filament and a pair of small ring-shaped magnets which confine the ionizing electrons to the interior or exterior periphery of the analyzer system per se; by the fact that the first pair of deflection magnets of the analyzer system is ring shaped; and by the fact that the selective action of the other fields, in particular the electrostatic fields, is due to the prior dispersion obtained by the first magnetic induction.

Abstract: Between the electrostatic sector (SE 23) and the magnetic sector (SM 30) of a mass spectrometer, there is provided a quadrupole (QP 26) which applies parallel beams to the magnetic sector whose inclination depends on the energy dispersion of the particles. A slotted lens (LF 27) corrects the divergence of the quadrupole in the perpendicular plane. A suitable relationship between the angle of the inlet face of the magnetic sector (SM 30) and the deflection angle provided thereby ensures that the second order aperture aberrations of the magnetic sector are corrected. The chromatic aberrations may be corrected by means of a hexapole (HP 25) centered on the focus of the quadrupole (QP 26). Another hexapole (HP 22) placed upstream from the electrostatic sector (SE 23) level with a constriction in vertical section of the particle beam serves to correct second order aperture aberrations related to the electrostatic sector (SE 23).

Abstract: A process of obtaining spectra of daughter ions which are produced by collision of sample ions with neutral molecules for dissociating the sample ions in a collision chamber disposed in an ion path to thereby provide a structural analysis of organic compounds. To carry out this process, a mass spectrometer is used which has mass spectrometric units located before and after the collision chamber. The spectrometric unit located behind the chamber has superimposed magnetic field B and electric field E perpendicular to the magnetic field. Daughter ions having a mass m.sub.x produced from parent ions having a mass m.sub.0 inside the chamber are detected and measured by sweeping the voltage Vd.sub.x for producing the electric field or the intensity B.sub.x of the magnetic field singly or sweeping both in an interrelated manner so as to satisfy the relation ##EQU1## where V.sub.00 is the voltage for producing the electric field used to detect the parent ions having infinitely large masses, B.sub.

Abstract: A mass spectrometer has a uniform magnetic field and an electric field. Further, the spectrometer is equipped with three spaced electrostatic quadrupole lenses. The deflection angle .phi..sub.m of the beam in the magnetic field, the radius r.sub.m of the circle described by the beam in the magnetic field, the deflection angle .phi..sub.e of the beam in the electric field, and the radius r.sub.e of the circle described by the beam in the electric field are so set as to satisfy the following relations:82.degree..ltoreq..phi..sub.e .ltoreq.88.degree.;39.degree..ltoreq..phi..sub.m .ltoreq.41.degree.0.715.ltoreq.r.sub.e /r.sub.m .ltoreq.0.755.The spectrometer can measure masses over a wide range even if it is built as a small-sized instrument. Thus, the instrument is able to measure molecular ions of large masses.

Abstract: A mass spectrometer and process for using same comprises an ion source, a first field, a second field and a field-free region between the first and second fields. Parent ions are mass-selected by said first field and daughter ions are formed in the field-free region by ion dissociation or ion fragmentation. The daughter ions are dispersed by the second field. Superimposed electric and magnetic fields are used as the second field, the intensity of said magnetic field being changed from a first stage to a second stage and the intensity of said electric field being swept under both stages. Both energy and mass of the daughter ions can be measured by this mass spectrometer.

Abstract: In a mass spectrometer of the magnetic field type for analyzing the mass of ions by causing an ion beam to pass through a narrow slit and then through a deflecting magnetic field to be detected by an ion detector where the intensity of the deflecting magnetic field is varied, plural electrostatic quadrupole lenses are provided between the source slit and the deflecting magnetic field so as to give a converging property to an ion beam passing in a direction vertical to the median plane thereof and to give a diverging property to an ion beam passing in the direction of the radius thereof. This minimizes the gap spacing between the magnetic pole pieces which form the deflecting magnetic field, thereby improving sensitivity and detection as well as accuracy and measurement.

Abstract: An ion mass spectrometer is described which detects and indicates the characteristics of ions received over a wide angle, and which indicates the mass to charge ratio, the energy, and the direction of each detected ion. The spectrometer includes a magnetic analyzer (18) having a sector magnet (24) that passes ions received over a wide angle, and an electrostatic analyzer (30) positioned to receive ions passing through the magnetic analyzer. The electrostatic analyzer includes a two dimensional ion sensor (32) at one wall of the analyzer chamber, that senses not only the lengthwise position of the detected ion to indicate its mass to charge ratio, but that also detects the ion position along the width of the chamber to indicate the direction in which the ion was travelling.

Abstract: A mass spectrometer comprising an ion source for producing an ion beam, an ion optical system having an entrance and an exit slit, and an ion detector. The ion optical system comprises a series combination of an energy dispersing unit and a mass dispersing unit. The energy dispersing unit comprises a toroidal electrical field having a deflection angle of 85.degree. to 95.degree. while the mass dispersing unit comprises a homogeneous magnetic field having a deflection angle of 85.degree. to 95.degree. and an entrance end face made concave as viewed from the entrance side of the ion beam when the apparatus is operated as a double focussing mass spectrometer of the reverse geometry type and an exit end face inclined 6.degree. to 14.degree. to the negative side from a position perpendicular to the axis of the ion optical system.

Abstract: A double focusing mass spectrometer having a diverging electrostatic field, a converging electrostatic field and a converging magnetic field. The two electrostatic fields are connected with each other without substantial free space therebetween. The ion beam passes through the electrostatic fields coming to an intermediate focus point adjacent to the ion exit boundary of said converging electrostatic field. The beam then passes through the magnetic field to satisfy the double focusing condition in combination with the electrostatic field. Very small image magnification and aberration free focusing are obtained by this mass spectrometer.

Abstract: The invention provides an improved apparatus for the detection of polar vapors in a gas which avoids the need for liquid reagents and requires little maintenance. In its simplest form the apparatus comprises a body member defining a passage through which a gas stream may be caused to pass; an ionizing source for ionizing the gas stream; and a collector electrode positioned in the passage downstream of the ionizing source for collecting ions carried by the gas stream. Improved performance can be obtained by the provision of means for selectively removing uncombined gas ions from the gas stream between the ionizing source and the collector electrode while permitting ion clusters formed on polar molecules to remain therein.

Abstract: In improved mass spectrometers of the double focussing zero second-order aberration type with first-order spectrograph properties, parameters are related by specific equations as a result of which the five aberration coefficients B.sub.1, B.sub.2, B.sub.11, B.sub.12 and B.sub.22 can all be simultaneously zero.

Abstract: A linked scan type mass spectrometer wherein the mass number of a metastable ion originating from a precursor ion is measured by scanning the magnetic and electric fields at a constant ratio between the two fields. Calculation is performed on a first electrical signal representative of the mass number of the precursor ion, a second electrical signal corresponding to a value of the electric field at which the mass number of the precursor ion is detected, and a third electrical signal corresponding to a value of the electric field at which the metastable ion is detected during scanning of the electric field and magnetic field, to thereby determine the mass number of the metastable ion. The third electrical signal is obtained by measuring a value of the magnetic field which contributes to the dispersion of ions. Means is provided for correcting the measured value of the magnetic field, thereby determining the mass number of the metastable ion with high accuracy.

Abstract: A tandem quadrupole-based mass spectrometer including a highly efficient intermediate fragmentation stage. The disclosed fragmentation stage employs collision-induced dissociation (CID), in an electrodynamic focus device, which may be a quadrupole operated in a broad band filter mode. The disclosed CID process occurs at low energy (e.g., less than 1 keV, but preferably 2 eV to 100 eV), and is quite different from the high energy (e.g, greater than 1 keV, and typically 3 keV to 10 keV) CID process in prior tandem instruments such as mass-analyzed ion kinetic energy spectrometry (MIKES) systems. The efficiency of the present CID fragmentation is as high as 65%.

Abstract: The invention relates to a mass spectrometer for rapid scanning. A magnetic sector focuses a collimated beam containing the various ion species in a focal plane. The focused beams reach this focal plane at an angle of 45.degree.. The beams emerging from this focal plane are refocused in an electrostatic deflector having parallel plates. One of these plates is provided with a slit through which the beams are received. Scanning is brought about by varying the voltage applied to the electrostatic deflector.

Abstract: The separated ion source combines an ion source and a magnetic mass separator within a single magnetic field geometry. The preferred ion source has a low voltage Penning discharge configuration and produces a charged particle beam in the form of a ribbon with a rectangular cross section.