Abstract: An ion transfer arrangement for transporting ions between higher and lower pressure regions of the mass spectrometer comprises an ion transfer conduit 60. The conduit 60 has an inlet opening towards a relatively high pressure chamber 40 and an outlet 70 opening towards a relatively low pressure chamber. The conduit 60 also has at least one side wall surrounding an ion transfer channel 115. The side wall includes a plurality of apertures 140 formed in the longitudinal direction of the side wall so as to permit a flow of gas from within the ion transfer channel 115 to a lower pressure region outside of the side wall of the conduit 60.

Abstract: Methods and analysers useful for time of flight mass spectrometry are provided.

Abstract: The invention relates to a vacuum pump or vacuum apparatus having a vacuum pump for the evacuation of one or a plurality of volumes, the vacuum pump having a plurality of pressure stages and at least two suction inlets. According to the invention, an outer suction inlet for a first pressure stage spatially encompasses an inner suction inlet for a second pressure stage such that the inner suction inlet seals only against pressure within the outer suction inlet, not against external pressure.

Abstract: A system and method of mass spectrometry is provided. Ions from an ion source are stored in a first ion storage device and in a second ion storage device. Ions are ejected from the first ion storage device to a first mass analysis device during a first ejection time period, for analysis during a first analysis time period. Ions are ejected from the second ion storage device to a second mass analysis device during a second ejection time period. The ion storage devices are connected in series such that an ion transport aperture of the first ion storage device is in communication with an ion transport aperture of the second ion storage device. The first analysis time period and the second ejection time period at least partly overlap.

Abstract: A method of reflecting ions in a multireflection time of flight mass spectrometer is disclosed. The method includes guiding ions toward an ion mirror having multiple electrodes, and applying a voltage to the ion mirror electrodes to create an electric field that causes the mean trajectory of the ions to intersect a plane of symmetry of the ion mirror and to exit the ion mirror, wherein the ion are spatially focussed by the mirror to a first location and temporally focused to a second location different from the first location. Apparatus for carrying out the method is also disclosed.

Abstract: A method of operating a gas-filled collision cell in a mass spectrometer is provided. The collision cell has a longitudinal axis. Ions are caused to enter the collision cell. A trapping field is generated within the collision cell so as to trap the ions within a trapping volume of the collision cell, the trapping volume being defined by the trapping field and extending along the longitudinal axis. Trapped ions are processed in the collision cell and a DC potential gradient is provided, using an electrode arrangement, resulting in a non-zero electric field at all points along the axial length of the trapping volume so as to cause processed ions to exit the collision cell. The electric field along the axial length of the trapping volume has a standard deviation that is no greater than its mean value.

Abstract: The present invention provides a radio frequency (RF) power supply in a mass spectrometer. The power supply provides an RF signal to electrodes of a storage device to create a trapping field. The RF field is usually collapsed prior to ion ejection. In an illustrative embodiment the RF power supply includes a RF signal supply; a coil arranged to receive the signal provided by the RF signal supply and to provide an output RF signal for supply to electrodes of an ion storage device; and a shunt including a switch operative to switch between a first open position and a second closed position in which the shunt shorts the coil output.

Abstract: Mass analysers and methods of ion detection for a mass analyser are provided. An electrostatic field generator provides an electrostatic field causing ion packets to oscillate along a direction. A pulse transient signal is detected over a time duration that is significantly shorter than a period of the ion oscillation or using pulse detection electrodes having a width that is significantly smaller than a span of ion harmonic motion. A harmonic transient signal is also detected. Ion intensity with respect to mass-to-charge ratio is then identified based on the pulse transient signal and the harmonic transient signal.

Abstract: The invention provides a data acquisition system and method for detecting ions in a mass spectrometer, comprising: a detection system for detecting ions comprising two or more detectors for outputting two or more detection signals in separate channels in response to ions arriving at the detection system; and a data processing system for receiving and processing the detection signals in separate channels of the data processing system and for merging the processed detection signals to construct a mass spectrum; wherein the processing in separate channels comprises removing noise from the detection signals by applying a threshold to the detection signals. The detection signals are preferably produced in response to the same ions, the signals being shifted in time relative to each other. The invention is suitable for a TOF mass spectrometer.

Abstract: A detection system and a method for detecting ions which have been separated in a time-of-flight (TOF) mass analyser, comprising an amplifying arrangement for converting ions into packets of secondary particles and amplifying the packets of secondary particles, wherein the amplifying arrangement is arranged so that each packet of secondary particles produces at least a first output and a second output separated in time and so that during the delay between producing the first and second output the first output produced by a packet of secondary particles is used for modulating the second output produced by the same packet. An increased dynamic range of detection and protection of the detection system against intense ion pulses is thereby provided.

Abstract: An ion trap comprises substantially elongate electrodes 10, 20 some of which are curved along their axis of elongation and which define a trapping volume between them. The sectional area of this trapping volume towards the extremities of the trap in the direction of elongation is different to the sectional area away from its extremities (eg towards the middle of the trap). In a preferred embodiment, the trap has a plurality of elongate electrodes, wherein opposed electrodes have different radii of curvature so that the trap splays towards its extremities. Thereby, a wider mass range of ions can be trapped and ejected, a higher space charge capacity (for a given trap length) is provided, and sharper ion beam focussing on ejection is possible.

Abstract: A method of separating ions according to their time of flight is provided comprising: a. providing an analyser comprising two opposing ion mirrors, each mirror comprising inner and outer field-defining electrode systems elongated along an analyser axis with the outer field-defining electrode system surrounding the inner field-defining electrode system and creating therebetween an analyser volume; b. injecting ions into the analyser volume or creating ions within the analyser volume so that they separate according to their time of flight as they travel along a main flight path whilst undergoing a plurality of axial oscillations in the direction of the analyser axis and a plurality of radial oscillations whilst orbiting about one or more inner field-defining electrodes; c. the plurality of axial oscillations and plurality of radial oscillations causing the separated ions to intercept an exit port after a predetermined number of orbits.

Abstract: A method of selecting ions of interest from a beam of ions using an analyser, the method comprising: (i) providing an analyser comprising two opposing ion mirrors each mirror comprising inner and outer field-defining electrode systems elongated along an analyser axis z, each system comprising one or more electrodes, the outer system surrounding the inner; (ii) causing the beam of ions to fly through the analyser along a main flight path in the presence of an analyser field so as to undergo within the analyser at least one full oscillation in the direction of the analyser axis whilst orbiting about or oscillating between one or more electrodes of the inner field defining electrode system; (iii) providing one or more sets of electrodes adjacent the main flight path; (iv) constraining the arcuate divergence from the main flight path of ions of interest by applying one set of voltages to one or more of the sets of electrodes adjacent the main flight path when the ions of interest are in the vicinity of at least o

Abstract: A vacuum pump for the evacuation of one or a plurality of volumes is described. The vacuum pump has a plurality of pressure stages and at least two suction inlets. An outer suction inlet for a first pressure stage spatially encompasses an inner suction inlet for a second pressure stage such that the inner suction inlet seals only against pressure within the outer suction inlet, not against external pressure.

Abstract: This invention relates to mass spectrometry that includes ion trapping in at least one of the stages of mass analysis. In particular, although not exclusively, this invention relates to tandem mass spectrometry where precursor ions and fragment ions are analysed. A method of mass spectrometry is provided comprising the sequential steps of: accumulating in an ion store a sample of one type of ions to be analysed; accumulating in the ion store a sample of another type of ions to be analysed; and mass analysing the combined samples of the ions; wherein the method comprises accumulating the sample of the one type of ions and/or the sample of another type of ions to achieve a target number of ions based on the results of a previous measurement of the respective type of ions.

Abstract: A method of increasing ion throughput within an accumulator, an energy lift and a pulsed ion extractor, operated in that order upon a batch of ions, comprising the steps of: firstly loading a batch of ions into the accumulator; secondly changing the electrical potential of the energy lift to raise the energy of the batch of ions contained therein; and thirdly ejecting the batch of ions from the pulsed ion extractor; and wherein: the energy lift is a separate device from the accumulator and the pulsed ion extractor, and whilst changing the electrical potential in the second step a fresh batch of ions is loaded into the accumulator and/or a previous batch of ions is prepared for ejection in the pulsed ion extractor; or the energy lift is incorporated into the pulsed ion extractor and whilst changing the electrical potential in the second step a fresh batch of ions is loaded into the accumulator; or the energy lift is incorporated into the accumulator and whilst changing the electrical potential in the second st

Abstract: A method of mass spectrometry having steps of, in a first cycle: storing sample ions in a first ion storage device, the first ion storage device having an exit aperture and a spatially separate ion transport aperture; ejecting the stored ions out of the exit aperture; transporting the ejected ions into an ion selection device which is spatially separated from the said first ion storage device; carrying out ion selection within the spatially separated ion selection device; returning at least some of the ions ejected from the first ion storage device, or their derivatives, back from the spatially separate ion selection device to the first ion storage device, following the step of ion selection; receiving the said returned ions through the ion transport aperture of the first ion storage device; and storing the received ions in the first ion storage device.

Abstract: A system and method of mass spectrometry is provided. Ions from an ion source are stored in a first ion storage device and in a second ion storage device. Ions are ejected from the first ion storage device to a first mass analysis device during a first ejection time period, for analysis during a first analysis time period. Ions are ejected from the second ion storage device to a second mass analysis device during a second ejection time period. The ion storage devices are connected in series such that an ion transport aperture of the first ion storage device is in communication with an ion transport aperture of the second ion storage device. The first analysis time period and the second ejection time period at least partly overlap.

Abstract: There is provided of an on mobility spectrometer for separating ions according to their on mobility comprising, in various aspects: a drift tube having therein a drift space and in the drift space at least two on separation paths of different lengths: a straight drift tube having therein a helical ion separation path; a helical on separation path surrounding an axially extending inner electrode assembly; and a drift tube for separating ions according to their ion mobility wherein a rotating arcuate electric field is applied in operation to separate ions having an ion mobility such that their rotational velocity in the drift tube is matched to the rotational velocity of the rotating arcuate electric field. Various methods for separating ions according to their on mobility are also provided.

Abstract: A method of reflecting ions in a multireflection time of flight mass spectrometer is disclosed. The method includes guiding ions toward an ion mirror having multiple electrodes, and applying a voltage to the ion mirror electrodes to create an electric field that causes the mean trajectory of the ions to intersect a plane of symmetry of the ion mirror and to exit the ion mirror, wherein the ion are spatially focussed by the mirror to a first location and temporally focused to a second location different from the first location. Apparatus for carrying out the method is also disclosed.