An orthogonal acceleration time-of-flight mass spectrometer (1) includes: an ion ejector (123) which ejects measurement-target ions in a predetermined direction; an orthogonal accelerator (132) which accelerates ions in a direction orthogonal to the direction in which the ions are ejected; a ring electrode (131) located between the ion ejector and the orthogonal accelerator, the ring electrode having an opening for allowing ions to pass through and arranged so that the central axis (C2) of the opening is shifted from the central axis (C1) of the ion ejector in a direction along the axis of the acceleration of the ions by the orthogonal accelerator; a reflectron electrode (134) which creates a repelling electric field for reversing the direction of the ions accelerated by the orthogonal accelerator; and an ion detector (135) which detects ions after the direction of flight of the ions is reversed by the reflectron electrode.

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.

A pulsed accelerator for a Time of Flight mass spectrometers comprising a set of parallel electrodes. The accelerator is inclined at an oblique angle to the incoming ion beam defined by the ratio of the incoming ion beam velocity spreads axial and transverse to the beam. Additionally a deflection electrode is included to deflect unwanted ions away from the detector during the fill cycle of the accelerator.

The invention provides (a) a time-of-flight mass spectrometer with an acceleration region, a single-stage or multi-stage reflector, and an ion detector, further comprising an additional reflector whose potential has, at least in a subregion, a two-dimensional logarithmic potential component and a two-dimensional octopole potential component, and (b) methods for operating the time-of-flight mass spectrometer.

An ion source may include an ionization chamber to be maintained at atmospheric-pressure. The ion source may further include a reduced-pressure chamber to be maintained at sub-atmospheric pressure, and an ion transfer device comprising an inlet in the ionization chamber and an outlet in the reduced-pressure chamber. The ion transfer device may define an ion path from the inlet to the outlet. The ion transfer device may be positioned to emit ions and neutral gas molecules from the outlet as an expanding beam comprising a low-gas density zone enveloped by a high-gas density region that includes a gas density that is higher than the low-gas density zone. The ion source may be utilized, for example, for ion mobility spectrometry (IMS), mass spectrometry (MS), and hybrid IM-MS.

A time-of-flight, TOF, mass spectrometer, MS, comprising: an ion source for supplying a group of ions, including a first ion having a first mass-to-charge ratio m.sub.1/z.sub.1, a second ion having a second mass-to-charge ratio m.sub.2/z.sub.2 and a third ion having a third mass-to-charge ratio m.sub.3/z.sub.3 wherein m.sub.3/z.sub.3>m.sub.2/z.sub.2>at a time t.sub.0; a first set of electrodes, including a first electrode, and a second set of electrodes, including a first electrode and an Nth electrode, wherein the first set of electrodes and the second set of electrodes are mutually spaced apart by a gap therebetween; an ion detector for detecting the ions; a set of power supplies, including a first power supply, electrically coupled to the first set of electrodes and to the second set of electrodes; and a controller configured to control the set of power supplies to apply respective potentials to the first set of electrodes and the second set of electrodes; wherein the controller is configured to control the set of power supplies to: provide a first substantially field-free region between the ion source and the first set of electrodes to allow the group of ions to expand theretowards and/or therein, at the time t0; apply an extraction potential V.sub.extraction to the first set of electrodes at a time t.sub.extraction>t.sub.0, to extract the expanded group of ions, while maintaining a second substantially field-free region beyond the first set of electrodes, in the gap between the first set of electrodes and the second set of electrodes; and optionally, change an acceleration potential V.sub.acceleration applied to the second set of electrodes during a time period Δt=t.sub.off−t.sub.on, wherein ton>t.sub.extraction, to vary acceleration of the extracted group of ions based, at least in part, on respective mass-to-charge ratios.

A time of flight mass spectrometer that includes a first electrode; and a second electrode that is spaced apart from the first electrode. The ion source is configured to apply voltages to the first and second electrodes to produce an electric field in a region between the first and second electrodes so as to influence ions present in the region between the first and second electrodes when the mass spectrometer is in use. A shield is formed on the first electrode and/or second electrode. The shield is configured to inhibit an electric field formed between edges of the first and second electrodes from penetrating into the region between the first and second electrodes when the mass spectrometer is in use

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.

An analytical device includes: a first acceleration unit including a first acceleration electrode to which a pulse voltage for accelerating ions is applied; a flight tube; a second acceleration unit that is arranged between the first acceleration unit and the flight tube, and includes a second acceleration electrode to which a voltage for accelerating the ions is applied; an ion detector that detects the ions; and a capacitance adjustment unit that causes adjustment of a capacitance between at least one set of electrodes among a plurality of electrodes arranged in the first acceleration unit, the second acceleration unit, and a flight tube.

A monolithic electrode includes a first portion devoid of apertures and a second portion surrounded by the first portion, the second portion having a web defining a plurality of apertures. A method for forming an electrode includes forming a first electrode portion devoid of apertures and forming a second electrode portion having a web defining a plurality of apertures. The web of the second electrode portion connects to the first electrode portion.