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 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: 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: 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: 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: 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: 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: 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.