Abstract: This invention relates to a mass spectrometer including a reaction cell and to a method of using such a mass spectrometer. In particular, although not exclusively, this invention relates to a tandem mass spectrometer and to tandem mass spectrometry. The invention provides a method of mass spectrometry using a mass spectrometer having a longitudinal axis, comprising guiding ions to travel along the longitudinal axis of the mass spectrometer in a forwards direction to pass through an intermediate ion store and then to enter a reaction cell, to process the ions within the reaction cell, to eject the processed ions to travel back along the longitudinal axis to enter the intermediate ion store once more, and to eject one or more pulses of the processed ions in an off-axis direction to a mass analyser.

Abstract: An electrostatic trap such as an orbitrap is disclosed, with an electrode structure. An electrostatic trapping field of the form U?(r, ?, z) is generated to trap ions within the trap so that they undergo isochronous oscillations. The trapping field U?(r, ?, z) is the result of a perturbation W to an ideal field U(r, ?, z) which, for example, is hyperlogarithmic in the case of an orbitrap. The perturbation W may be introduced in various ways, such as by distorting the geometry of the trap so that it no longer follows an equipotential of the ideal field U(r, ?, z), or by adding a distortion field (either electric or magnetic). The magnitude of the perturbation is such that at least some of the trapped ions have an absolute phase spread of more than zero but less than 2 ? radians over an ion detection period Tm.

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: An electrode for influencing ion motion in mass spectrometers, having a dielectric substrate and a conducting layer on portions of the substrate, wherein peripheral borders, edges or convex shapes of the conducting layer adjoin free regions of the substrate. According to the invention, a dielectric layer is provided on transitions from the conducting layer to the adjoining free regions of the substrate such that at least some of the peripheral borders, edges or convex shapes of the conducting layer are covered.

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: A method of changing the kinetic energy of ions is provided, comprising: trapping ions in a trapping region of an ion trap; and directing a beam of gas through the trapping region, so as to change the kinetic energy of the trapped ions thereby. Also provided is a method of separating ions, the method comprising: causing ions to enter a trapping region of an ion trap along a first axis of the trapping region; directing a beam of gas along the first axis and applying an electric potential in the direction of the first axis so as to cause separation of the ions based on their ion mobility. An ion trap and a mass spectrometer for performing the methods are also provided.

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: This invention relates to a method of trapping ions and to an ion trapping assembly. In particular, the present invention has application in gas-assisted trapping of ions in an ion trap prior to a mass analysis of the ions in a mass spectrometer. The invention provides a method of trapping ions in a target ion trap of an ion trapping assembly that comprises a series of volumes arranged such that ions can traverse from one volume to the next, the volumes including the target ion trap, whereby ions are allowed to pass repeatedly through the volumes such that they also pass into and out from the target ion trap without being trapped. Potentials may be used to reflect the ions from respective ends of the ion trapping assembly. Optionally, a potential well and/or gas-assisted cooling may be used to cause the ions to settle in the target ion trap.

Abstract: This invention relates to a method of trapping ions and to an ion trapping assembly. In particular, the present invention has application in gas-assisted trapping of ions in an ion trap prior to a mass analysis of the ions in a mass spectrometer. The invention provides a method of trapping ions in a target ion trap of an ion trapping assembly that comprises a series of volumes arranged such that ions can traverse from one volume to the next, the volumes including the target ion trap, whereby ions are allowed to pass repeatedly through the volumes such that they also pass into and out from the target ion trap without being trapped. Potentials may be used to reflect the ions from respective ends of the ion trapping assembly. Optionally, a potential well and/or gas-assisted cooling may be used to cause the ions to settle in the target ion trap.

Abstract: An electrode for influencing ion motion in mass spectrometers, having a dielectric substrate and a conducting layer on portions of the substrate, wherein peripheral borders, edges or convex shapes of the conducting layer adjoin free regions of the substrate. According to the invention, a dielectric layer is provided on transitions from the conducting layer to the adjoining free regions of the substrate such that at least some of the peripheral borders, edges or convex shapes of the conducting layer are covered.

Abstract: This invention relates to a mass spectrometer including a reaction cell and to a method of using such a mass spectrometer. In particular, although not exclusively, this invention relates to a tandem mass spectrometer and to tandem mass spectrometry. The invention provides a method of mass spectrometry using a mass spectrometer having a longitudinal axis, comprising guiding ions to travel along the longitudinal axis of the mass spectrometer in a forwards direction to pass through an intermediate ion store and then to enter a reaction cell, to process the ions within the reaction cell, to eject the processed ions to travel back along the longitudinal axis to enter the intermediate ion store once more, and to eject one or more pulses of the processed ions in an off-axis direction to a mass analyser.

Abstract: An electrostatic trap such as an orbitrap is disclosed, with an electrode structure. An electrostatic trapping field of the form U?(r, ?, z) is generated to trap ions within the trap so that they undergo isochronous oscillations. The trapping field U?(r, ?, z) is the result of a perturbation W to an ideal field U(r, ?, z) which, for example, is hyperlogarithmic in the case of an orbitrap. The perturbation W may be introduced in various ways, such as by distorting the geometry of the trap so that it no longer follows an equipotential of the ideal field U(r, ?, z), or by adding a distortion field (either electric or magnetic). The magnitude of the perturbation is such that at least some of the trapped ions have an absolute phase spread of more than zero but less than 2 ? radians over an ion detection period Tm.

Abstract: This invention relates to a mass spectrometer including a reaction cell and to a method of using such a mass spectrometer. In particular, although not exclusively, this invention relates to a tandem mass spectrometer and to tandem mass spectrometry. The invention provides a method of mass spectrometry using a mass spectrometer having a longitudinal axis, comprising guiding ions to travel along the longitudinal axis of the mass spectrometer in a forwards direction to pass through an intermediate ion store and then to enter a reaction cell, to process the ions within the reaction cell, to eject the processed ions to travel back along the longitudinal axis to enter the intermediate ion store once more, and to eject one or more pulses of the processed ions in an off-axis direction to a mass analyser.

Abstract: An electrostatic trap such as an orbitrap is disclosed, with an electrode structure. An electrostatic trapping field of the form U?(r,?,z) is generated to trap ions within the trap so that they undergo isochronous oscillations. The trapping field U?(r, ?,z) is the result of a perturbation W to an ideal field U(r, ?,z) which, for example, is hyperlogarithmic in the case of an orbitrap. The perturbation W may be introduced in various ways, such as by distorting the geometry of the trap so that it no longer follows an equipotential of the ideal field U(r, ?,z), or by adding a distortion field (either electric or magnetic). The magnitude of the perturbation is such that at least some of the trapped ions have an absolute phase spread of more than zero but less than about 2? radians over an ion detection period Tm.

Abstract: The present invention relates to a method and apparatus for ion fragmentation by electron capture. The present invention provides a method of generating fragment ions by electron capture, comprising; directing ions to be fragmented into a fragmentation chamber of a mass spectrometer into a fragmentation chamber of a mass spectrometer arrangement; trapping at least some of the ions to be fragmented in at least one direction of the fragmentation chamber by using a magnetic field, the ions being trapped within a volume V; generating an electron beam using an electron source located away from the volume V; irradiating the trapped ions in the volume V with the electrons generated by the electron source in the presence of the said magnetic field, so as to cause dissociation; and ejecting the resultant fragment ions from the fragmentation chamber for subsequent analysis at a different location away from the fragmentation chamber.

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: 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. Such ion storage devices are often used to store ions prior to ejection to a subsequent mass analyzer. The RF field is usually collapsed prior to ion ejection. The present invention provides a RF power supply comprising: 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 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: An electrostatic trap such as an orbitrap is disclosed, with an electrode structure. An electrostatic trapping field of the form U?(r,?,z) is generated to trap ions within the trap so that they undergo isochronous oscillations. The trapping field U?(r, ?,z) is the result of a perturbation W to an ideal field U(r, ?,z) which, for example, is hyperlogarithmic in the case of an orbitrap. The perturbation W may be introduced in various ways, such as by distorting the geometry of the trap so that it no longer follows an equipotential of the ideal field U(r, ?,z), or by adding a distortion field (either electric or magnetic). The magnitude of the perturbation is such that at least some of the trapped ions have an absolute phase spread of more than zero but less than about 2? radians over an ion detection period Tm.

Abstract: This invention relates to a mass spectrometer including a reaction cell and to a method of using such a mass spectrometer. In particular, although not exclusively, this invention relates to a tandem mass spectrometer and to tandem mass spectrometry. The invention provides a method of mass spectrometry using a mass spectrometer having a longitudinal axis, comprising guiding ions to travel along the longitudinal axis of the mass spectrometer in a forwards direction to pass through an intermediate ion store and then to enter a reaction cell, to process the ions within the reaction cell, to eject the processed ions to travel back along the longitudinal axis to enter the intermediate ion store once more, and to eject one or more pulses of the processed ions in an off-axis direction to a mass analyser.

Abstract: This invention relates to a method of trapping ions and to an ion trapping assembly. In particular, the present invention has application in gas-assisted trapping of ions in an ion trap prior to a mass analysis of the ions in a mass spectrometer. The invention provides a method of trapping ions in a target ion trap of an ion trapping assembly that comprises a series of volumes arranged such that ions can traverse from one volume to the next, the volumes including the target ion trap, whereby ions are allowed to pass repeatedly through the volumes such that they also pass into and out from the target ion trap without being trapped. Potentials may be used to reflect the ions from respective ends of the ion trapping assembly. Optionally, a potential well and/or gas-assisted cooling may be used to cause the ions to settle in the target ion trap.