Abstract: A mass spectrometer comprises an ion detector, a first amplifier, a second amplifier, and a spectra combiner. The ion detector is configured to generate an analog signal indicative of ions detected by the ion detector. The first amplifier is configured to amplify the analog signal to provide a first amplified signal having a first gain relative to the analog signal. The second amplifier is configured to amplify the analog signal to provide a second amplified signal having a second gain relative to the analog signal, and the first gain is different than the second gain. The spectra combiner is configured to combine first summed digital samples of the first amplified signal with second summed digital samples of the second amplified signal.

Abstract: A first mass spectrum and a second mass spectrum of the same ion sample can be analyzed to determine reaction pairs. These reaction pairs are determined based on a selected neutral difference by shifting the second mass spectrum by the neutral difference relative to the first mass spectrum to provide a shifted mass spectrum. Then, the shifted mass spectrum is compared with the first mass spectrum of the ion sample to determine the reaction pairs based on the neutral difference.

Abstract: A multi-purpose efficient charge particle detector that by switching bias voltages measures either secondary ions, or secondary electrons (SE) from a sample, or secondary electrons that originate from back scattered electrons (SE3), is described. The basic version of the detector structure and two stripped down versions enable its use for the following detection combinations: The major version is for measuring secondary ions, or secondary electrons from the sample, or secondary electrons due to back-scattered electrons that hit parts other than the sample together or without secondary electrons from the sample. Measuring secondary ions or secondary electrons from the sample (no SE3). Measuring secondary electrons from the sample and/or secondary electrons resulting from back-scattered electrons hitting objects other than the sample (no ions).

Abstract: A mass spectrometer is disclosed comprising a segmented linear ion guide or ion trap. Ions are confined radially within the ion guide or ion trap by the application of an AC or RF voltage to the electrodes forming the ion guide or ion trap. A quadratic DC potential is applied along the axial length of the ion guide or ion trap in order to cause trapped ions to perform simple harmonic motion within the ion guide or ion trap. The frequency of the oscillations of the ions is detected using one or more inductive detectors. The mass to charge ratio of the ions can then be determined from the determined frequency of oscillations.

Abstract: A MEMS mass spectrometer having metal walls connected between a lid and base, with the walls defining a plurality of interior chambers including sample gas input chambers, an ionizer chamber, a plurality of ion optics chambers and a ion separation chamber. A detector array at the end of the ion separation chamber includes a plurality of V-shaped detector elements positioned along two parallel lines and arranged to intercept all of the ionized beams produced in the mass spectrometer.

Abstract: A coded mass spectrometer incorporates a spatial or temporal code to reduce the resolution/sensitivity dichotomy inherent in mass spectrometry. The code is used to code one or more portions of a mass spectrometer. Coding patterns, such as Hadamard codes, Walsh codes, and perfect code sequences can be used. The coding can be spatial, for example, by using an aperture mask and/or temporal, for example, by coded injection of ions for analysis.

Abstract: A preparative mass spectrometer system includes an ionizer which converts the mixture into gas phase ions of the molecules in the mixture, and a separator which separates the ions according to their mass to charge ratio or mobility. The separator is a linear ion trap mass analyzer that accumulates the ions based on their mass to charge ratio. A surface is in cooperative relationship with the separator so that the separated molecules are soft landed onto the surface at different locations such that the collected molecules can be stored or further processed/analyzed.

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

Abstract: A method of separating species in a mixture of molecules, particles or atoms and collecting the separated species is described. The method comprises the steps of converting by ionization the species in the mixture to gas phase ions, separating the gas phase ions according to their mass charge ratio and/or mobility and collecting the separated ions. The system includes ionizing means such as electrospray to form the gas phase ions. The gas phase ions are separated by filtering, or in time or in space and soft-landed for collection such as on a surface.

Abstract: In the field of mass spectrometry, a method of obtaining a mass spectrum enriched with fragment ions while retaining the precursor ion. The technique includes varying the collision energy experienced by the precursor ion such that a range of fragmentations occur. Related methods are also disclosed for obtaining MS, MS2, MS3 and MSn spectra which are enriched with fragment ions.

Abstract: A mass spectrometer includes: an ion source for ionizing a specimen to generate ions, an ion transport portion for transporting the ions, a linear ion trap portion for accumulating the transported ions by a potential formed axially, and a control portion of ejecting the ions within a second m/z range different from a first m/z range, from the linear ion trap portion, and substantially at the same timing as the timing of accumulating the ions within the first m/z range from the transport portion into the linear ion trap portion. The ion transportation portion having a mass selection means for selecting the ions in the first m/z range.

Abstract: This invention discloses an ion implantation apparatus with multiple operating modes. It has an ion source and an ion extraction means for extracting a ribbon-shaped ion beam therefrom. The ion implantation apparatus includes a magnetic analyzer for selecting ions with specific mass-to-charge ratio to pass through a mass slit to project onto a substrate. Multipole lenses are provided to control beam uniformity and collimation. The invention further discloses a two-path beamline in which a second path incorporates a deceleration system incorporating energy filtering. The invention discloses methods of ion implantation in which the mode of implantation may be switched from one-dimensional scanning of the target to two-dimensional scanning, and from a simple path to an s-shaped path with deceleration.

Abstract: The present invention relates to an apparatus and method for focusing, separating, and detecting gas-phase ions using the principles of electrohydrodynamic quadrupole fields at high pressures, at or near atmospheric pressure. Ions are entrained in a concentric flow of gas and travel through a high-transmission element into a RF/DC quadrupole, exiting out of the RF/DC quadrupole, and then impacting on an ion detector, such as a faraday plate; or through an aperture or capillary tube with subsequent identification by a mass spectrometer. Ions with stable trajectories pass through the RF/DC quadrupole while ions with unstable trajectories drift off-axis collide with the rods and are lost. Alternatively, detection of ions with unstable trajectories can be accomplished by allowing the ions to pass through the rods and be detected by an off-axis detector.

Abstract: A detection scheme for time-of-flight mass spectrometers is described that extends the dynamic range of spectrometers that use counting techniques while avoiding the problems of crosstalk. It is well known that a multiple anode detector capable of detecting different fractions of the incoming particles may be used to increase the dynamic range of a TOFMS system. However, crosstalk between the anodes limits the amount by which the dynamic range may be increased. The present invention overcomes limitations imposed by crosstalk by using either a secondary amplification stage or by using different primary amplification stages.

Abstract: A charged particle beam detection system that includes a Faraday cup detector array (FCDA) for position-sensitive charged particle beam detection is described. The FCDA is combined with an electronic multiplexing unit (MUX) that allows collecting and integrating the charge deposited in the array, and simultaneously reading out the same. The duty cycle for collecting the ions is greater than 98%. This multiplexing is achieved by collecting the charge with a large number of small and electronically decoupled Faraday cups. Because Faraday cups collect the charge independent of their charge state, each cup is both a collector and an integrator. The ability of the Faraday cup to integrate the charge, in combination with the electronic multiplexing unit, which reads out and empties the cups quickly compared to the charge integration time, provides the almost perfect duty cycle for this position-sensitive charged particle detector. The device measures further absolute ion currents, has a wide dynamic range from 1.

Abstract: Ion mobility spectrometer apparatus may include an ion interface that is operable to hold positive and negative ions and to simultaneously release positive and negative ions through respective positive and negative ion ports. A first drift chamber is operatively associated with the positive ion port of the ion interface and encloses an electric field therein. A first ion detector operatively associated with the first drift chamber detects positive ions from the first drift chamber. A second drift chamber is operatively associated with the negative ion port of the ion interface and encloses an electric field therein. A second ion detector operatively associated with the second drift chamber detects negative ions from said second drift chamber.

Abstract: A high sensitivity glow discharge ion source system for analyzing particles includes an aerodynamic lens having a plurality of constrictions for receiving an aerosol including at least one analyte particle in a carrier gas and focusing the analyte particles into a collimated particle beam. A separator separates the carrier gas from the analyte particle beam, wherein the analyte particle beam or vapors derived from the analyte particle beam are selectively transmitted out of from the separator. A glow discharge ionization source includes a discharge chamber having an entrance orifice for receiving the analyte particle beam or analyte vapors, and a target electrode and discharge electrode therein. An electric field applied between the target electrode and discharge electrode generates an analyte ion stream from the analyte vapors, which is directed out of the discharge chamber through an exit orifice, such as to a mass spectrometer.

Abstract: The present invention is directed to a bipolar ion detector capable of detecting both positive and negative ions in a single configuration. The invention uses either a single microchannel plates or a stack of microchannel plates to convert the ion signal into an amplified electron signal. Circuitry allows the anode to be biased (floated) to a positive high voltage and efficiently couple the signal from the anode out to recording electronics at ground.

Abstract: Aerosol particle analyzer (APA) for measuring an analyte in airborne particle is described. Airborne particles are first given an electrical charge and then drawn in air past an oppositely charged volume of an analysis liquid that exposed to the air at a small hole in a container, such as a capillary, that holds that analysis liquid. Electrostatic forces enhance the rate that the airborne particles collide with the small exposed volume of the analysis liquid in the hole. If the particles that collide with the analysis liquid contain the analyte, an optical property of the analysis liquid, such as the fluorescence, varies according to the amount of the analyte in the particles. This optical property is measured and the amount of analyte in the particles is determined from the measured optical property.

Abstract: An aerosol-into-liquid collector (ALC) for collecting gas-borne particles from a large volume of gas such as air into a small volume of liquid is described. The ALC uses a linear quadrupole to concentrate particles flowing in a gas and to help direct these concentrated particles toward a small volume of collection liquid so that these particles tend to combine with a small volume of collection liquid that can then be drawn from the ACL for further analysis. The particles in the gas are typically given a charge that is opposite to that of the charge imparted to the volume of collection liquid so that electrostatic forces help draw particles from the flowing gas into the small volume of liquid. The linear quadrupole focuses toward it axis particles that have the charge, mass and mobility to be stable in the linear quadrupole.

Abstract: In the field of mass spectrometry, a method of obtaining a mass spectrum enriched with fragment ions while retaining the precursor ion. The technique includes varying the collision energy experienced by the precursor ion such that a range of fragmentations occur. Related methods are also disclosed for obtaining MS, MS2, MS3 and MSn spectra which are enriched with fragment ions.

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

Abstract: Aerosol particle analyzer (APA) for measuring the amount of analyte in airborne particle is described. The APA uses an analysis liquid. In most embodiments, this analysis liquid is chosen so that when it is mixed with the particles, an optical property of the analysis liquid (AL) varies according to the amount of the analyte in the particles. Airborne particles are drawn into the instrument, and detected using optical methods such as light scattering or laser-induced fluorescence. When a particle of interest is detected, a charged droplet of the analysis liquid (CDAL) is ejected so that it collides with the detected particle and moves into a horizontally oriented linear quadrupole that is in an airtight container, except for small orifices to let the CDAL enter and exit.

Abstract: A detection scheme for time-of-flight mass spectrometers is described that extends the dynamic range of spectrometers that use counting techniques while avoiding the problems of crosstalk. It is well known that a multiple anode detector capable of detecting different fractions of the incoming particles may be used to increase the dynamic range of a TOFMS system. However, crosstalk between the anodes limits the amount by which the dynamic range may be increased. The present invention overcomes limitations imposed by crosstalk by using either a secondary amplification stage or by using different primary amplification stages.

Abstract: Aerosol particle analyzer (APA) for measuring the amount of analyte in airborne particle is described. The APA uses an analysis liquid. When this analysis liquid is mixed with the particles, an optical property of the analysis liquid (CDAL) varies according to the amount of the analyte in the particles. A charged droplet of the analysis liquid is levitated. Airborne particles are drawn into the instrument and given a charge that is opposite that of the CDAL, and made to flow near the CDAL so that electrostatic forces greatly increase the probability that the CDAL and charged particles will combine. Then the CDAL is ejected into a horizontally oriented linear quadrupole that is in an airtight container, except for a small orifice to let the CDAL enter. The CDAL is levitated in a high humidity environment so that it evaporates slowly, so that there is time for the reaction between the analyte, if any, and the CDAL can take place, and so that the optical property, typically fluorescence, can be measured.

Abstract: The present invention provides a windowframe magnet having an aligned array of paired bedstead coils in mirror symmetry can bend a high aspect ratio ribbon ion beam through angle of not less than about 45 degrees and not more than about 110 degrees, and can focus it through a resolving slot for mass analysis. The long transverse axis of the beam, which can exceed 50% of the bend radius, is aligned with the generated magnetic field. The array of paired bedstead coils provide tight control of the fringing fields, present intrinsically good field uniformity, and enable a manufacture of much lighter construction than other magnet styles conventionally in use in the ion implantation industry. Within the system of the present invention, the ribbon beam is refocused with low aberration to achieve high resolving power, which is of significant value in the ion implantation industry. System size is further reduced by using a small ion source and a quadrupole lens to collimate the beam after expansion and analysis.

Abstract: An apparatus for an ion trap includes a semiconductor or dielectric wafer with front and back surfaces, a sequence of alternating conductive and dielectric layers formed over said front surface, and a bottom conductive layer. The sequence includes top and middle conductive layers, wherein the middle conductive layer is closer to the wafer than the top conductive layer. The middle conductive layer includes a substantially right cylindrical cavity that crosses a width of the middle conductive layer. The top and bottom conductive layers cap respective first and second ends of the cavity. The top conductive layer includes a hole that forms a first access port to the cavity. The wafer includes via through the width of the wafer. The via provides another access to the cavity via the back surface of the wafer. The wafer is substantially thicker than the sequence of layers.

Abstract: A solid state compact ion gauge includes an electron source, a gate electrode, an electron collector, a gas ionizer, an ion anode, and a detector all formed within a cavity of a semiconductor substrate formed of two halves bonded together and having open sides for receiving a gase sample. A sample of gas having multiple gas constituents flows into the cavity from the side where gas molecules collide with electrons flowing from the source to the collector forming ions. The ions are forced under an electric field to the detector which includes a set of detectors for sensing the constituent ions.

Abstract: The invention describes an ion cyclotron resonance (ICR) mass spectrometer with an ICR trap, the ICR trap having as trapping electrodes two ion reflecting electrode structures operated by RF voltages without any DC voltage. The usual apertured ion trapping electrodes are replaced by multitudes of structural elements, electrically conducting, and repeating spatially in one or two directions of a surface, neighboring structure elements being connected each to different phases of an RF voltage. In the simplest case a grid of parallel wires can be used. The surface of such structures reflects ions of both polarities, if the mass-to-charge ratio of the ions is higher than a threshold.

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

Abstract: A MALDI plate suitable for MS or MS-MS analysis provided with a composite coating that comprises a hydrophobic coating and a thin layer coating of a mixture of a MALDI matrix material and an intercalating agent such as a polymer is disclosed. A MALDI plate produced in accordance with the present teachings is useful for suppression of matrix ions in the low mass region (<1,000 daltons) of a MALDI-MS spectrum.

Abstract: The present invention provides methods and electronic circuits for a chemical analyzer, for example, a mass spectrometer, which provide generated signals that are maintained to a required level of precision. A user may specify the required precision for the signals which operate the spectrometer and may specify the required precision for the mass analysis, either explicitly or by choosing a predefined configuration. The spectrometer will then generate the signals to the required precision despite changes in operating conditions, environmental conditions, component aging and degradation, or other nonfailure effects that otherwise affect analyzer calibration and signal output. The electronic circuits incorporate signal monitoring to maintain closed-loop signal control. The closed-loop control includes a feedback path which may include discrete components and may include software enabling a processor to adjust the generated signals to maintain the required precision of the signals and analysis.

Abstract: A mass spectrometer suitable to measure both positive and negative particles, such as ions for example in a vacuum chamber. This spectrometer is provided with a turnable permanent magnet segment, which provides the gap of a yoke with adequate magnetic flux having the appropriate direction to separate the positive or the negative particles. Changing the polarity adjusts the flight path of the ions. Thus, negatively charged ions and positively charged ions will follow similar flight paths under opposite polarities, permitting the use of a single array of detectors. One or more coils may be used in place of or in addition to the turnable permanent magnet segment in order to provide the appropriate magnetic flux to the gap, and/or facilitate the turning process of the turnable magnet segment. The turnable magnet and/or the coils may be inside or outside the vacuum chamber.

Abstract: An ion mass spectrometer comprising an ionization source for generating ions, a linear trap region for accumulation and dissociation of ions, and a time-of-flight mass spectrometer for mass spectroscopy of ions based on the flying time, and having a collision damping region introduced with a buffer gas for reducing the kinetic energy of ions ejected from the linear trap region and converting the ion packet into continuous beam and provided with plural electrodes for generating multipole electric fields in the inside between the linear trap region and the time-of-flight mass spectrometer, and having an ion transmission control mechanism for allowing or inhibiting incidence of ion from the linear trap region to the collision damping region between the linear trap region and the collision damping region.

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

Abstract: A hollow exciting current pathway in the form of a conductor is arranged outside of an ion deflection casing with a curved contour and having an inlet and an outlet. The conductor 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 an ion beam greater in size can be ion mass separated uniformly.

Abstract: In semiconductor manufacturing equipment having a residual gas analyzing apparatus for analyzing the composition of residual gas in a process chamber of the equipment a heater of the residual gas analyzer is interlocked with a heater of the process chamber. The residual gas analyzer includes an ion detector, and the heater of the residual gas analyzer has a filament and a heating jacket surrounding a portion of the ion detector. A relay connects a power source of the heater for the process chamber to the heater of the residual gas analyzer. Power is supplied to and cut off from the heater of the residual gas analyzer in response to heater on/off signals used for controlling the operation for the heater for the process chamber.

Abstract: The present invention relates to devices and methods for determining the masses of particles by measuring the time between a first event such as a sample (5) being ionized, (or a beam of electromagnetic radiation being scattered by a particle (15) and electromagnetic radiation scattered by said particle being detected by a detection means,) and a second event in which a beam (21) of electromagnetic radiation is scattered by a particle (15) from said ionized sample and electromagnetic radiation (25) from said beam (21) scattered by said particle (15) is detected by a detection means (11).

Abstract: This invention provides a system and method for measuring an energy differential that correlates to quantitative measurement of an amount mass of an applied localized material. Such a system and method remains compatible with other methods of analysis, such as, for example, quantitating the elemental or isotopic content, identifying the material, or using the material in biochemical analysis.

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

Abstract: The invention relates to a compact time-of-flight mass spectrometer which enables very accurate mass determinations. The invention consists of a method of producing a high resolution by means of a long flight path, where the ion beam repeatedly sweeps a figure of eight in two opposed cylindrical capacitors, each of 254.56°, and the linear ion beam paths between the cylindrical capacitors are extended virtually by a change in potential so as to cause a time focusing with respect to an initial energy spread.

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

Abstract: A method and apparatus for the analysis of a narrow range of fragment ions by application of a notched broadband waveform during ion accumulation within a quadrupole collision cell operated as a linear ion trap. The fragment ions are formed via the axial acceleration and collision activated dissociation of mass resolved precursor ions. A narrow band of frequencies is purposefully omitted from the spectrum, so that the secular frequency of a particular fragment ion will fall within this notch of absent frequencies and as a result will not experience resonant excitation and are retained in the linear ion trap. Simultaneously, all other ions are lost either through neutralization when they strike electrodes or through (additional) collision activated dissociation. Accordingly, a particular mass or range of masses, whose secular frequencies fall within the notch of absent frequencies in the notched broadband waveform, may be selectively accumulated during the collision activated dissociation event.

Abstract: There is provided a tandem mass spectrometry that, in a quadrupole ion trap, allows small mass-number product ions to be detected without lowering the sensitivity and the resolution. In the quadrupole ion trap, ions are produced by an ion source. Next, the ions are accumulated within a 3-dimensional quadrupole electric field formed by a pair of endcap electrodes and a ring electrode. Finally, the accumulated ions are isolated and dissociated, then being detected. In this quadrupole ion trap, there are provided a mechanism for introducing a laser light, and a mechanism for generating a supplemental alternating-current electric field at the time of the ion dissociation. Moreover, the direction of the supplemental alternating-current electric field and the introduction direction of the laser light are made identical to each other.

Abstract: The present invention relates to an apparatus and method for focusing, separating, and detecting gas-phase ions using the principles of quadrupole fields, substantially at or near atmospheric pressure. Ions are entrained in a concentric flow of gas and travel through a high-transmission element into a RF/DC quadrupole, through a second high-transmission element, and then impact on an ion detector, such as a faraday plate; or through an aperture with subsequent identification by a mass spectrometer. Ions with stable trajectories pass through the RF/DC quadrupole while ions with unstable trajectories drift off-axis collide with the rods and are lost. Embodiments of this invention are devices and methods for focusing, separating and detecting gas-phase ions without the need for a vacuum chamber when coupled to atmospheric ionization sources.

Abstract: A summed TOFMS having a filter for identifying detector outputs that are likely the result of noise rather than ions striking the ion detector. The TOFMS stores a plurality of data values at locations specified by a register that counts clock pulses. The filter receives the ion measurements from the ion detector and generates an output measurement value corresponding to each ion measurement. The filter sets the output measurement value to a predetermined baseline value if the filter determines that the ion measurement is noise, otherwise the filter sets the output measurement value to the ion measurement. An adder, responsive to the clock signal, forms the sum of the data value specified by the register value and the output measurement value and stores the sum in the memory at the location corresponding to the register value.

Abstract: In a high-sensitivity X-ray detector, an image of the secondary electrons is little shifted and deformed by the astigmatism or the like even when it approaches very close to a specimen set on the stage of an electron microscope. When a beam of charged particles strike a specimen, the specimen emits backscattered charged particles along with X-rays. To prevent such undesired charged particles from entering into the X-ray detecting element of the X-ray detector, a means for generating a first magnetic field is applied. Another means for generating a second magnetic field is provided to cancel the magnetic filed leaked from the first means for generating magnetic field at the position of the specimen.

Abstract: The present invention describes a method of selecting ions in an ion storage device with high resolution in a short time period while suppressing amplitude of ion oscillation immediately after the selection. In a method of selecting ions within a specific range of mass-to-charge ratio by applying an ion-selecting electric field in an ion storage space of an ion storage device, the method according to the present invention is characterized in that the ion-selecting electric field is produced from a waveform whose frequency is substantially scanned, and the waveform is made anti-symmetric by multiplying a weight function whose polarity reverses, or by shifting a phase of the waveform by odd multiple of &pgr;, at around a secular frequency of the ions to be left in the ion storage space. It is preferable that the frequency of the waveforms is scanned in a direction where the frequency decreases.

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