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: A Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) is provided. A preamplifier is installed as nearest to an ion cyclotron resonance (ICR) trap as possible at a detector part in the mass spectrometer, and thermal noise generated at the preamplifier is minimized by means of a cryo-cooling system to increase a signal-to-noise ratio of ion detection signals such that an ultra-low amount of specimen can be detected, which was impossible in the related art.

Abstract: An asymmetric field ion mobility spectrometer for filtering ions via an asymmetric electric field, an ion flow generator propulsing ions to the filter via a propulsion field.

Abstract: Apparatus and method for trapping uncharged multi-pole particles comprises a bound cavity for receiving the particles, and a multiplicity of electrodes coupled to the cavity for producing an electric field in the cavity. In a preferred embodiment, the electrodes are configured to produce in the electric field potential both a multi-pole (e.g., dipole) component that aligns the particles predominantly along an axis of the cavity and a higher order multi-pole (e.g., hexapole) component that forms a trapping region along the axis. In one embodiment, the electrodes and/or the particles are cooled to a cryogenic temperature.

Abstract: An adjustable, low mass-to-charge (m/z) filter is disclosed employing electrospray ionization to block ions associated with unwanted low m/z species from entering the mass spectrometer and contributing their space charge to down-stream ion accumulation steps. The low-mass filter is made by using an adjustable potential energy barrier from the conductance limiting terminal electrode of an electrodynamic ion funnel, which prohibits species with higher ion mobilities from being transmitted. The filter provides a linear voltage adjustment of low-mass filtering from m/z values from about 50 to about 500. Mass filtering above m/z 500 can also be performed; however, higher m/z species are attenuated. The mass filter was evaluated with a liquid chromatography-mass spectrometry analysis of an albumin tryptic digest and resulted in the ability to block low-mass, “background” ions which account for 40-70% of the total ion current from the ESI source during peak elution.

Abstract: In an ion cyclotron resonance mass spectrometer in which ions are trapped axially by applying electrical potentials to a pattern of electrode elements to produce an inhomogeneous alternating radio-frequency electric field with a repulsive effect, an additional electrostatic ion-attracting field is superimposed on the repulsive electric field. The voltage of the ion-attracting field is adjusted to compensate for a cyclotron frequency shift of the ions caused by the ion space charge. The voltage of the ion-attracting field can be adjusted so that the ion cyclotron frequency of all ions becomes independent of the number of ions inside the spectrometer.

Abstract: A variable duty cycle ion source assembly is coupled to a continuous beam mass spectrometer. The duty cycle can be adjusted based on previous scan data or real time sampling of ion intensities during mass analysis. This provides the ability to control the total number of ions formed, mass analyzed and detected for each ion mass of interest. The frequency of the ion source can be sufficiently high (kHz range) so as to maintain accurate peak centroiding. The ion source assembly can be used for both electron ionization (EI) or chemical ionization (CI) modes of operation.

Abstract: An electrode for use in a device such as an ion trap has an axial length extending generally in the direction of a central axis from a first axial end to a second axial end, and an inside surface. The inside surface includes a surface profile that is uniform from the first axial end to the second axial end, or at least is uniform for a uniform section length along the axial direction. The electrode may include an elongated surface feature such as a groove that extends for at least the uniform section length. An aperture may communicate with the groove. The electrode may be axially segmented into regions. Gaps between the regions may be oriented at an angle relative to a plane orthogonal to the central axis. The electrode may be one of several electrodes arranged as an electrode structure coaxially disposed about an elongated interior space.

Abstract: Briefly described, embodiments of the present disclosure include: confining/focusing vortex flow transmission structures, mass spectrometry systems including a confining/focusing vortex flow transmission structure, methods of using the confining/focusing vortex flow transmission structure, methods of using mass spectrometry system, methods of transmitting droplets and ions, methods of evaporating droplets and desolvating ions, and the like.

Abstract: The invention relates to measuring methods and corresponding measuring cells for ion cyclotron resonance mass spectrometers (FTMS). The invention provides measuring methods with measuring cells, the ends of which each incorporate a large number of trapping electrodes, DC voltages of opposite polarities being applied across adjacent electrodes. For orbiting ions this builds up a repelling pseudopotential, which holds the ions in the measuring cell by reflection. This facilitates measurement of the image currents without the disturbing influence of RF voltages.

Abstract: The invention provides an apparatus for producing an image of a global surface of an ion source sample plate that is exterior to an ion source. In general terms, the apparatus contains a sample plate for an ion source, an imaging device (e.g., a CCD or CMOS camera) and an illumination device that is configured to produce a light beam that contacts the sample plate surface to define a grazing angle between the light beam and the sample plate surface. The apparatus may be present at a location that is remote to the ion source.

Abstract: An ion cyclotron spectrometer may include a vacuum chamber that extends at least along a z-axis and means for producing a magnetic field within the vacuum chamber so that a magnetic field vector is generally parallel to the z-axis. The spectrometer may also include means for producing a trapping electric field within the vacuum chamber that includes at least a first section that induces a first magnetron effect that increases a cyclotron frequency of an ion and at least a second section that induces a second magnetron effect that decreases the cyclotron frequency of an ion. The cyclotron frequency changes induced by the first and second magnetron effects substantially cancel one another so that an ion traversing the first and second sections will experience no net change in cyclotron frequency.

Abstract: A method of generating a mass spectrum from an FTMS is disclosed. A first quantity of ions from a source, having a first m/z range, is captured and detected in the FTMS measurement cell to produce a first output. A second quantity of ions, having a second m/z range which at least partially does not overlap with the first m/z range, is then captured and detected so as to produce a second output. The two outputs are then combined using a processor so as to “stitch” together the outputs, which may be FTMS transients or may first be Fourier Transformed into the frequency mass domain, into a composite output from which a composite mass spectrum covering the full range of m/z ratios included by the first and second ranges can be produced.

Abstract: In a time of flight mass spectrometer (TOFMS) having a flight space in which ions fly in a loop orbit formed by a plurality of electric sector fields, the present invention provides a simple structure that creates a spiral path by deflecting the ions in the axial direction of the electric fields at every turn of the ions. In a mode of the present invention, the TOFMS has cylindrical electrodes 11 and 12 for creating electric sector fields E1 and E2, between which a parallel pair of planer magnetic poles 15a and 15b are provided. The planer magnetic poles 15a and 15b create a deflecting magnetic field B1 for shifting the ions in the axial direction (Y-direction) of the electric sector fields. The ions experience a Lorenz force once every turn when they pass through the deflecting magnetic field B1. This construction uses only one pair of magnetic poles facing each other across the ion path P to deflect every ion irrespective of its number of turns.

Abstract: A detector system for detecting trace molecules. The detector includes an ion trap that is coupled to an ionizer and a detector. The system also includes a controller that can generate voltage potentials within the ion trap. The controller can generate a voltage waveform to isolate one or more ions within the ion trap. The controller can then generate a voltage to dissociate the isolated ion(s). The controller can vary the dissociating voltage to dissociate and detect different ions. For example, the controller may vary the amplitude of the voltage to dissociate a target ion. Other techniques are described which generally improve the speed of detecting different target ions.

Abstract: A tandem Fourier transform ion cyclotron resonance mass spectrometer is provided. In the mass spectrometer, the ions selected by a FT-ICR mass analyzer, which can perform an ion selection process and a mass measurement process with a time interval between the processes, are transmitted through an ion guide to a collision cell, which is located a predetermined distance from the FT-ICR mass analyzer, to split into fragment ions. The fragment ions are transmitted to the FT-ICR mass analyzer that measures the mass of the fragment ions. The fragment ions are generated in the collision cell 60 established separately from the FT-ICR mass analyzer 40 according to the mass spectrometer. Accordingly, It can solve various problems (e.g., the radius reduction of cyclotron motion of colliding ions, or the removal of periphery gas after generating the fragment ions) occurred in a tandem mass spectrometer using a conventional tandem-in-time mass analysis method.

Abstract: An electrode structure for manipulating ions includes a main electrode and a compensation electrode. An outer surface of the main electrode includes a curved section that includes an apex. An aperture is generally disposed at the apex and extends along a radial center line from the outer surface through a thickness of the main electrode. The compensation electrode is disposed at the radial center line and at a tangent line tangent to the apex. Another electrode structure includes a plurality of main electrodes defining an interior space, and one or more compensation electrodes disposed in the interior space. RF signals may be applied to the main electrodes and to the compensation electrode.

Abstract: An apparatus for an improved cyclotron for producing radioisotopes especially for use in association with medical imaging. The improved cyclotron is configured without a conventional electromagnetic coil. A plurality of dees and a plurality of permanent magnets are alternately disposed in a circular array, each defining a channel through which ions travel. The vacuum chamber wall defines an opening disposed at the center of the array, the opening being configured to receive an ion source. Positive ions flowing from the ion source are exposed to the magnetic field generated by permanent magnets. The positive ions are repelled as they exit a positively charged dee. Negatively charged dees pull the ions. Each time the particles pass through the gap approaching the dees and as they leave the dee and pass through the magnets, they gain energy, so the orbital radius continuously increases and the particles follow an outwardly spiraling path.

Abstract: The invention provides a mass spectrometry system ion source containing a sample plate and an illumination device that is configured to produce a light beam that contacts the sample plate surface to define a grazing angle between the light beam and the sample plate surface. The ion source may also contain an imaging device, e.g., a CCD or CMOS camera or the like, for viewing the area. In one embodiment, the imaging device may be connected to a display, e.g., a video monitor. Methods and mass spectrometry systems empliying the ion source are also provided.

Abstract: A medical synchrotron which cycles rapidly in order to accelerate particles for delivery in a beam therapy system. The synchrotron generally includes a radiofrequency (RF) cavity for accelerating the particles as a beam and a plurality of combined function magnets arranged in a ring. Each of the combined function magnets performs two functions. The first function of the combined function magnet is to bend the particle beam along an orbital path around the ring. The second function of the combined function magnet is to focus or defocus the particle beam as it travels around the path. The radiofrequency (RF) cavity is a ferrite loaded cavity adapted for high speed frequency swings for rapid cycling acceleration of the particles.

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 coaxial hybrid ion trap that uses two substantially planar opposing plates to generate electrical focusing fields that simultaneously generate at least two different types or shapes of trapping regions, wherein a first trapping region is a quadrupole trapping region disposed coaxially with respect to the opposing plates, and wherein a second trapping region is a toroidal ion trap having a toroidal trapping region that is simultaneously created around the quadrupole trapping region.

Abstract: A mass spectrometer is provided in which ions are favorably introduced into a loop orbit or favorably led out from the loop orbit without affecting the motion of the ions flying along the loop orbit. An ion-introduction orbit 5 is set to correspond to the orbit (ejection orbit portion 4) of ions after being bent by the sector-shaped electric field E1 in the loop orbit 4. When ions are introduced, a voltage applied to the electrode unit 11 is put to zero to release the sector-shaped electric field E1. Then the ions emitted along the ion-introduction orbit 5 fly straight in the electrode unit 11. The direction and position of the ions coming out from the exit end of the electric field is the same as those ions flying along the loop orbit 4. Therefore, there is no need for placing a deflection electrode for introducing/leading-out ions on the loop orbit.

Abstract: An atmospheric pressure ionization mass spectrometry system has an atmospheric pressure ionization chamber for ionizing a sample, an evacuated intermediate evacuation chamber into which generated ions are introduced through a capillary tube, and a vacuum chamber further downstream therefrom into which ions are introduced for mass separation. A partition wall separating the atmospheric pressure ionization chamber from the intermediate evacuation chamber includes a small orifice having a diameter corresponding to an internal channel diameter of the capillary tube. The capillary tube is detachably installed on the partition wall so that an outlet end of the capillary tube abuts on the small orifice. The internal channel of the capillary tube is in communication with the small orifice. The capillary tube can be installed and removed from the system without breaching the vacuum.

Abstract: A time of flight mass spectrometer according to the present invention includes: a) an ion source at which an ion starts flying; b) an energizer for giving a predetermined amount of energy to the ion to let the ion start flying from the ion source; c) an ion guide for forming a time-focusing flight path on which the ion flies once or repeatedly; d) a detector for detecting the ion after flying the flight path; e) an analysis controller for giving different amounts of energy to ions of the same kind using the energizer, and for measuring the values of the flight time of the ions from the ion source to the detector for the amount of energy; and f) a mass calculator for calculating or estimating the mass to charge ratio of the ion based on the difference in the values of the flight time of the ions.

Abstract: The present invention relates to, inter alia, methods and apparatuses for electron transfer dissociation (ETD) that vary the internal energy of precursor ions for ETD. The methods and apparatuses are particularly useful in mass spectrometry.

Abstract: A mass spectrometer having an ion source section capable of creating positive ions and negative ions at high efficiency. The ion source is comprised of an ion source section for creating ions of a sample gas, a mass spectrometric section for conducting mass separation of created ions, linear RF generating multipole electrodes, magnetic fields generation means, a sample gas introduction system, a reaction gas introduction system and an electron source in which the linear RF generating multipole electrodes generate linear RF multipole electric fields. A static magnetic fields is applied in parallel on the center axis where the linear RF multipole electric fields are zero. A sample gas and a reagent gas are introduced into the ion source section. Electrons are injected for creating reaction of the positive ions or negative ions.

Abstract: The invention relates to RF voltage-operated ion guides based on stacked apertured diaphragms. The invention provides ion guides consisting of diaphragm stacks that permit the ion beam to be shaped in cross-section so that it corresponds to the acceptance profile of the subsequent section of the device, therefore yielding optimal ion transmission. For this purpose, at least some of the diaphragms in the diaphragm stacks do not have circular openings, but instead have openings which shape the cross section of the emerging ion beam in the desired manner. It is possible, for instance, to obtain elliptical beam cross sections, divided beams or beams focused to the shape of a fine thread at the output of the diaphragm stacks.

Abstract: An improved rotating electric field ion mass spectrometer (REFIMS) provides for a smooth transition of the input ion beam from zero rotation to the desired level of field rotation. The REFIMS grid shape is changed from a fixed-diameter tunnel to that of a horn. The horn shape has a flare end with a larger entrance width that reduces the grid electric field strength to near zero and causes no abrupt deflection of the beam at the entrance, and tapers along the longitudinal z axis to a narrower width so that the field strength applied to the beam increases gradually until the correct field strength is obtained at its exit end for the desired rotation of the beam. Preferably, the horn shape in cross-section is hyperbolic, and the increase in field strength is approximately linear with distance along the z axis. The horn shaped device can provide a 2D spectral readout in which the ions are imaged on the target plane at radial positions increasing linearly with decreasing atomic mass units (amu).

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 virtual ion trap that uses electric focusing fields instead of machined metal electrodes that normally surround the trapping volume, wherein two opposing surfaces include a plurality of uniquely designed and coated electrodes, and wherein the electrodes can be disposed on the two opposing surfaces using plating techniques that enable much higher tolerances to be met than existing machining techniques.

Abstract: The invention relates to a measuring cell for an ion cyclotron resonance mass spectrometer (FTMS). The invention provides a measuring cell which, on the one hand, consists of two ion-repelling RF grids at the front ends as trapping electrodes and thus produces a pure cyclotron motion of the ions without the usually co-existing magnetron motion and, on the other hand, measures a multiplied cyclotron frequency by means of a plurality of detection electrodes, whereby either a higher mass accuracy or a shorter measuring time can be achieved.

Abstract: Disclosed is apparatus and method for improving the signal by changing the voltage applied to an analyzing trap of a high resolving power Fourier Transform Ion Cyclotron Resonance (FT-ICR) mass spectrometer. More specifically, after the ion activation, a voltage different from that of a trap electrode is applied to an additional electrode in the center of the trap electrode, and the voltage is maintained until the end of a detection cycle. Applying the above method, the stability of the ions confined in a trap is more increased, and therefore, the detected time domain signal is being lengthened. The lengthened time domain signal results in an increase of the frequency or an improvement of the resolving power and the sensitivity of the mass-to-charge domain signal.

Abstract: An improved ion funnel design is disclosed that decreases the axial RF (parasite) fields at the ion funnel exit. This is achieved by addition of one or more compensation electrodes after the conductance limit electrode. Various RF voltage profiles may be applied to the various electrodes minimizing the parasite axial potential wells. The smallest RF aperture that serves as the conductance limiting electrode is further reduced over standard designs. Overall, the ion funnel improves transmission ranges of both low m/z and high m/z ions, reducing RF activation of ions and decreasing the gas load to subsequent differential pumping stages.

Abstract: This invention relates to a measuring cell for an Ion Cyclotron Resonance (ICR) spectrometer. The present invention provides a measurement cell for an FTMS spectrometer, comprising an excitation electrode arrangement positioned about a longitudinal axis which extends in a direction generally parallel to the field direction of an applied homogeneous magnetic field; and a trapping electrode arrangement, also positioned about the said longitudinal axis, for trapping ions longitudinally in the cell within a trapping region defined by the trapping electrode arrangement; wherein at least a part of the excitation electrode arrangement extends axially outwardly of the trapping region defined by the trapping electrode arrangement.

Abstract: An ion spectrometer apparatus is disclosed having an ion source, an ion mobility spectrometer device such as a FAIMS cell, and a capillary for transporting ions from the ion source to the entrance of the FAIMS cell. The capillary is heated to promote evaporation of solvent from incompletely desolvated droplets entering the capillary inlet, thereby preventing or minimizing operational problems associated with the presence of wet material in the FAIMS cell. The FAIMS cell may be used to selectively transmit ions to a mass analyzer.

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: The invention provides, in various embodiments, systems and methods relating to controlling ion behavior in an ion-based analysis system.

Abstract: An ion cyclotron resonance cell has at least one trapping electrode comprised of electrically isolated sections that are used for the detection of an induced ion image signal. Such an arrangement increases the sensitivity of image signal detection without a significant increase in the amplitude of parasitic harmonics. When a multielectrode detection arrangement is used, the resolving power of an analyzer incorporating such a cyclotron resonance cell multiplies without a corresponding sensitivity loss.

Abstract: Apparatus and method for trapping uncharged multi-pole particles comprises a bound cavity for receiving the particles, and a multiplicity of electrodes coupled to the cavity for producing an electric field in the cavity. In a preferred embodiment, the electrodes are configured to produce in the electric field potential both a multi-pole (e.g., dipole) component that aligns the particles predominantly along an axis of the cavity and a higher order multi-pole (e.g., hexapole) component that forms a trapping region along the axis. In one embodiment, the electrodes and/or the particles are cooled to a cryogenic temperature.

Abstract: In the mass spectrometer of the present invention, first the length of flight time of a known ion is measured at every turn of the loop orbit. Ideally, the length of flight time at every turn is equal to one calculated based on the speed of the ion and the path length of the loop orbit, but an actual length of flight time deviates from it in a reproducible fashion. Thus, in the present invention, the deviation information is stored in the correction memory at every turn. In measuring an unknown ion, the unknown ion is made to fly the loop orbit a predetermined number of times. Then the flight time of the unknown ion that has flown the loop orbit a predetermined number of turns is measured, and the deviations of the flight time at the turns are corrected using the correction data stored in the correction memory. The mass to charge ratio of the unknown ion is calculated based on the corrected flight time.

Abstract: A virtual ion trap that uses electric focusing fields instead of machined metal electrodes that normally surround the trapping volume, wherein two opposing surfaces include a plurality of uniquely designed and coated electrodes, and wherein the electrodes can be disposed on the two opposing surfaces using plating techniques that enable much higher tolerances to be met than existing machining techniques.

Abstract: Disclosed is a high field asymmetric waveform ion mobility spectrometer (FAIMS) having a side-to-side electrode geometry. The FAIMS includes an inner electrode (102) having a length and an outer surface that is curved in a direction transverse to the length. The FAIMS also includes an outer electrode (104) having a length, a channel extending therethrough along at least a portion of the length, and a curved inner surface, a portion of the length of the outer electrode overlapping a portion of the length of the inner electrode so as to provide an analyzer region therebetween. The outer electrode has an ion inlet (114) for introducing ions from a source of ions into the analyzer region and an ion outlet (112) for extracting ions from the analyzer region, the ion inlet and the ion outlet being disposed on opposing sides of the outer electrode.

Abstract: Certain exemplary embodiments provide a method for automatically optimizing an FTMS. The method can comprise a plurality of potential activities, some of which can be automatically, repeatedly, and/or nestedly performed, and some of which follow. A composite amplitude relating to an FTMS spectral output signal for each of a plurality of FTMS samples can be obtained, each of the samples having an substantially similar number of molecules. The FTMS variable can be changed repeatedly and the composite amplitude re-obtained until a value of an optimization parameter substantially converges, the optimization parameter a function of the composite amplitude.

Abstract: The invention, in various embodiments, is directed to a solid-state flow generator and related systems, methods and applications.

Abstract: An improved FT-ICR Mass Spectrometer has an ion source 10 which generates ions that are transmitted through a series of multipoles 20 to an ion trap 30. Ions are ejected from the trap 30, through a series of lens and multipolar ion guide stages 40–90, and into a measurement cell 100 via an exit/gate lens 110. The measurement cell is mounted in a vacuum chamber 240 and this assembly is slideably moveable into a bore of a superconducting magnet 400 which provides the magnetic filed to cause cyclotron motion of the generated ions in the cell 100. By minimising the distance between the source 10 and cell 100, and by careful alignment of the ion optics, the ions can travel at high energies right up to the front of the measurement cell 100. The cell 100 extends in the longitudinal direction of the magnet bore and is coaxial with that. The ratio of the sectional area of the magnet bore to the sectional area of the cell volume is small (less than 3).

Abstract: In the mass spectrometer of the present invention, a flight space is provided before the mass analyzer, and the flight space includes a loop orbit on which ions fly repeatedly. While ions fly on the loop orbit repeatedly, ion selecting electrodes placed on the loop orbit selects object ions having a specific mass to charge ratio in such a manner that, for a limited time period when the object ions are flying through the ion selecting electrodes, an appropriate voltage is applied to the ion selecting electrodes to make them continue to fly on the loop orbit, but otherwise to make or let other ions deflect from the loop orbit. If ions having various mass to charge ratios are introduced in the loop orbit almost at the same time, the object ions having the same mass to charge ratio continue to fly on the loop orbit in a band, but ions having mass to charge ratios different from that are separated from the object ions while flying on the loop orbit repeatedly.

Abstract: Ion separation in a FAIMS analyzer is affected by the presence of neutral species and solvent vapor. A diffuser element, which is fabricated from a porous material, is disposed within a curtain gas chamber adjacent to the FAIMS ion inlet, such that a flow of a curtain gas is blocked from flowing directly out through a curtain gas orifice. The porous material creates a pressure drop across the diffuser and results in the flow of curtain gas being provided out of the curtain gas orifice, along a direction that is approximately perpendicular to a plane containing the curtain gas orifice. The perpendicular gas flow opposes ions traveling toward the curtain gas orifice from an ionization source, thereby desolvating the ions. Providing a perpendicular curtain gas flow for desolvating ions reduces the ion losses that are normally associated with the curtain gas flow deflecting some of the ions away from the curtain gas orifice and toward a curtain plate electrode.

Abstract: An aperture design for a linear ion trap is provided in which the aperture is optimized to minimize possible axial field inhomogeneities whilst preserving the structural integrity of the quadrupole rods. In general, the invention provides a linear ion trap for trapping and subsequently ejecting ions. The linear ion trap comprises a plurality of rods which define an interior trapping volume which has an axis extending longitudinally. One or more of the rods includes an aperture which extends both radially through the rod and longitudinally along the rod. The aperture being configured such that the ions can pass from the interior trapping volume through the aperture to a region outside the interior trapping volume. At least one recess is disposed adjacent the aperture, extending longitudinally along the rod and facing the interior trapping volume, the recess not extending radially through the rod.

Abstract: An ion detector having a planar electrically conducting entrance plate, a converter assembly including a planar electrically conducting converter plate and a converter member for providing free electrons upon impact of ions, a planar electrically conducting exit plate having an exit window, a magnet assembly, and an electron detection assembly. The planes of the converter plate and the entrance plate are parallel and electrically biasable in order to provide a homogeneous electric field. The magnet assembly provides a homogenous magnetic field between the converter plate and the exit plate, the magnetic field extending parallel to the plane of the converter plate. The ratio between the electric and the magnetic field is such that the electrons emitted from the converter plate travel to the exit window and are detected by the electron detection assembly.