A Fourier Transform electrostatic linear ion trap (ELIT) is disclosed with an electron multiplier detector comprising one of a microchannel plate and a channel electron multiplier. An (ELIT) is provided comprising a central axis along which ions travel; an image current detector disposed at least partially around the central axis of the ELIT; and an electron multiplier detector arranged in an opening of the image current detector, the electron multiplier detector being operable to receive ions deflected from the central axis. The electron multiplier detector may have a front surface that is perpendicular to the central axis of the ELIT. The electron multiplier detector may comprise two separate elements at non-normal angles to the central axis of the ELIT. The image current detector may comprise a cylinder with the opening on one side in which the electron multiplier detector is arranged, a U-shape, or a half-tube detector.

Improved multi-pass time-of-flight mass spectrometers MPTOF, either multi-reflecting (MR) or multi-turn (MT) TOF are proposed with elongated pulsed converters—either orthogonal accelerator or radially ejecting ion trap. The converter 35 is displaced from the MPTOF s-surface of isochronous ion motion in the orthogonal Y-direction. Long ion packets 38 are pulsed deflected in the transverse Y-direction and brought onto said isochronous trajectory s-surface, this way bypassing said converter. Ion packets are isochronously focused in the drift Z-direction within or immediately after the accelerator, either by isochronous trans-axial lens/wedge 68 or Fresnel lens. The accelerator is improved by the ion beam confinement within an RF quadrupolar field or within spatially alternated DC quadrupolar field. The accelerator improves the duty cycle and/or space charge capacity of MPTOF by an order of magnitude.

There is provided a method of decoding a first data set obtained from a time of flight (ToF) mass analyser operating according to an encoded frequency pulsing (EFP) scheme. The method comprises generating a mock data set based on a model set of ions taking account of the EFP pattern and the flight time distribution of the ions. The model set of ions is then iteratively updated using the first data set to determine a second, decoded data set.

A time-of-flight mass spectrometer (TOF MS) comprises a mass analyzer, an ion pushing device, a filtering device, a multi-pass reflector, a detector, and a decoder. The ion pushing device is arranged to push ions into the mass analyzer. The filtering device is arranged to filter a portion of the ions based on a mass range of the ions. The multi-pass reflector is arranged to selectively reflect the ions for further passes through the mass analyzer. The detector is arranged to receive the ions. The decoder is arranged to reconstruct a mass spectrum for the entire mass range of the ions.

A Time of Flight mass analyser is disclosed comprising: at least one ion mirror 34 for reflecting ions; an ion detector 36 arranged for detecting the reflected ions; a first pulsed ion accelerator 30 for accelerating an ion packet in a first dimension (Y-dimension) towards the ion detector 36 so that the ion packet spatially converges in the first dimension as it travels to the detector 36; and a pulsed orthogonal accelerator 32 for orthogonally accelerating the ion packet in a second, orthogonal dimension (X-dimension) into one of said at least one ion mirrors 34.

A time-of-flight (ToF) mass spectrometer, comprising: a pulsed ion injector for forming an ion beam that travels along an ion path; a detector for detecting ions in the ion beam that arrive at the detector at times according to their m/z values; an ion focusing arrangement located between the ion injector and the detector for focusing the ion beam in at least one direction orthogonal to the ion path; and a variable voltage supply for supplying the ion focusing arrangement with at least one variable voltage that is dependent on a charge state and/or an amount of ions of at least one species of ions in the ion beam. A corresponding method of mass spectrometry is provided. The charge state and/or an amount of ions may be acquired from a pre-scan, or predicted. Tuning of the spectrometer based on a charge state and/or an amount of ions of at least one species of ions in the ion beam may be performed on the fly.

An electrode assembly, such as for an ion mirror, comprising: a first layer having a plurality of electrodes that are separated by one or more gaps; a second layer arranged to cover said one or more gaps and prevent electric fields passing through said one or more gaps, said second layer having electrically conductive material located to be coincident with said one or more gaps in the first layer.

Improved multi-pass time-of-flight mass spectrometers MPTOF, either multi-reflecting (MR) or multi-turn (MT) TOF are proposed with elongated pulsed converters—either orthogonal accelerator or radially ejecting ion trap. The converter 35 is displaced from the MPTOF s-surface of isochronous ion motion in the orthogonal Y-direction. Long ion packets 38 are pulsed deflected in the transverse Y-direction and brought onto said isochronous trajectory s-surface, this way bypassing said converter. Ion packets are isochronously focused in the drift Z-direction within or immediately after the accelerator, either by isochronous trans-axial lens/wedge 68 or Fresnel lens. The accelerator is improved by the ion beam confinement within an RF quadrupolar field or within spatially alternated DC quadrupolar field. The accelerator improves the duty cycle and/or space charge capacity of MPTOF by an order of magnitude.

Improved ion mirrors (10) are proposed for multi-reflecting TOF MS and electrostatic traps at various analyzer topologies. Ion mirrors (10) are constructed of printed circuit boards (11) with improved precision and flatness. To compensate for the remaining geometrical imperfections of mirror electrodes there are proposed electrode sets (17) and field structures in the ion retarding region for electronically adjusting of the ion packets time fronts, for improving the ion injection into the analyzer and for reversing the ion motion in the drift direction.

Disclosed embodiments include a time-of-flight mass spectrometer with a straight ion optical axis comprising: an ion gate is electrically insolated electrode on which applied voltages to reject/pass ions through ion gate, entrance module and exit module set in focus/mirror modes, and create ion optical image on image plane located in field view aperture, electrostatic object lens, entrance module in focus mode and, transport electrostatic lens, exit module in focus mode and projection lens focused and map ions from image plane of field view aperture to image plane of ion detector, projection lens configured to form ion optical image of sample holder on image plane of ion detector and ion optical components with corrected geometrical, chromatic and timed aberrations configured to compensate time arriving disturbance in image plane of ion detector and improve mass and spatial resolution of image on image plane of ion detector.