A multi-reflecting time-of-flight mass spectrometer comprises a pair of parallel aligned ion mirrors and a set of periodic lenses for confining ion packets along the drift z-direction. To compensate for time-of-flight spherical aberrations T|zz created by the periodic lenses, at least one set of electrodes are disposed within the apparatus, forming an accelerating or reflecting electrostatic fields which are curved in the z-direction in order to form local negative T|zz aberration. The structure may be formed within an accelerator, within flinging fields or intentionally and locally curved fields of ion mirrors, within electrostatic sector interface, or at curved surface of ion to electron converter at the detector.

Improved pulsed ion sources and pulsed converters are proposed for multi-pass time-of-flight mass spectrometer, either multi-reflecting (MR) or multi-turn (MT) TOF. A wedge electrostatic field 45 is arranged within a region of small ion energy for electronically controlled tilting of ion packets 54 time front. Tilt angle γ of time front 54 is strongly amplified by a post-acceleration in a flat field 48. Electrostatic deflector 30 downstream of the post-acceleration 48 allows denser folding of ion trajectories, whereas the injection mechanism allows for electronically adjustable mutual compensation of the time front tilt angle, i.e. γ=0 for ion packet in location 55, for curvature of ion packets, and for the angular energy dispersion. The arrangement helps bypassing accelerator 40 rims, adjusting ion packets inclination angles α.sub.2, and what is most important, compensating for mechanical misalignments of the optical components.

A method of data independent MS-MS analysis is disclosed. The method comprises ramping or stepping in small steps of a wide (at least 10 amu) parent mass window in a first parent selecting mass spectrometer (MS1), arranging rapid ion transfer through a collisional cell, either by axial gas flow or by an axial DC field or by a travelling RF wave, frequently pulsing an orthogonal accelerator with a string of time-encoded pulses, analyzing fragment ions in a multi-reflecting time-flight mass spectrometer, acquiring data in a data logging format, and decoding signal strings corresponding to the entire scan of parent masses, such that fragment spectra are formed based on time correlation between fragment and parent masses. Frequent pulsing is expected to recover parent and fragment time correlation with an accuracy of approximately 1 Th, in spite of using much wider mass window in the first MS.

A method of mass spectral analysis in an analytical electrostatic trap (14) is disclosed. The electrostatic trap (14) defines an electrostatic field volume and includes trap electrodes having static and non-ramped potentials. The method comprises injecting a continuous ion beam into the electrostatic field volume.

A Time of Flight mass analyzer is disclosed comprising an annular ion guide having a longitudinal axis and comprising a first annular ion guide section and a second annular ion guide section. Ions are introduced into the first annular ion guide section so that the ions form substantially stable circular orbits within the first annular ion guide section about the longitudinal axis. The ions are then orthogonally accelerated ions from the first annular ion guide section into the second annular ion guide section. An ion detector is disposed within the annular ion guide and has an ion detecting surface arranged in a plane which is substantially perpendicular to the longitudinal axis.

Improved ion mirrors (30) (FIG. 3) are proposed for multi-reflecting TOF MS and electrostatic traps. Minor and controlled variation by means of arranging a localized wedge field structure (35) at the ion retarding region was found to produce major tilt of ion packets time fronts (39). Combining wedge reflecting fields with compensated deflectors is proposed for electrically controlled compensation of local and global misalignments, for improved ion injection and for reversing ion motion in the drift direction. Fine ion optical properties of methods and embodiments are verified in ion optical simulations.

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.

An instrument for separating ions may include an ion source configured to generate ions from a sample, at least one ion separation instrument configured to separate the generated ions as a function of at least one molecular characteristic and an electrostatic linear ion trap (ELIT) positioned to receive ions exiting the at least one ion separation instrument. The ELIT has first and second ion mirrors separated by a charge detection cylinder, and is configured such that an ion trapped therein oscillates back and forth through the charge detection cylinder between the first and second ion mirrors with a duty cycle, corresponding to a ratio of time spent by the trapped ion traversing the charge detection cylinder and total time spent by the trapped ion traversing a combination of the first and second ion mirrors and the charge detection cylinder during one complete oscillation cycle, of approximately 50%.

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.

An improved multi-pass time-of-flight or electrostatic trap mass spectrometer (70) with an orthogonal accelerator, applicable to mirror based multi-reflecting (MR) or multi-turn (MT) analyzers. The orthogonal accelerator (64) is tilted and after first ion reflection or turn the ion packets are back deflected with a compensated deflector (40) by the same angle α to compensate for the time-front steering and for the chromatic angular spreads. The focal distance of deflector (40) is control by Matsuda plates or other means for producing quadrupolar field in the deflector. Interference with the detector rim is improved with dual deflector (68). The proposed improvements allow substantial extension of flight path and number of ion turns or reflections. The problems of analyzer angular misalignments by tilting of ion mirror (71) is compensated by electrical adjustments of ion beam (63) energy and deflection angles in deflectors (40) and (68).