A multipole rod set of an ion guide is adapted to receive a radial RF trapping voltage and a radial dipole direct current DC voltage. A lens electrode of the ion guide is positioned at one end of the multipole rod set to extract ions from the multipole rod set and adapted to receive an axial trapping AC voltage and a DC voltage. A radial dipole DC voltage is applied to the multipole rod set and an axial trapping AC voltage is simultaneously applied to a lens electrode in order to extract a bandpass mass range of ions trapped in the multipole rod set. Alternatively, a radial RF trapping voltage amplitude is applied to the multipole rod set and an axial trapping AC voltage is simultaneously applied to the lens electrode in order to extract a bandpass mass range of ions trapped in the multipole rod set.

The invention relates to time-of-flight mass spectrometers which operate with pulsed ionization of superficially adsorbed analyte substances and with an improvement in the mass resolution by means of a time-delayed start of the ion acceleration; in particular with ion-accelerating voltages which change over time after a delayed start in order to obtain a constant mass resolution over broad mass ranges. Since the varying acceleration produces a broadening of the ion beam at right angles to the direction of flight, and this broadening increases with the ion mass, the invention proposes to compensate, to the desired extent, for the broadening of the ion beam with the aid of an additional ion-optical lens whose voltage is also varied over time. The invention also relates to measurement methods therefor.

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).

A lead-in electrode, of an orthogonal acceleration time-of-flight mass spectrometer, includes: a main body having an ion passing part and a first member including a main-body accommodating part that is a through-hole. One surface of the first member includes an extension part to define a position of one surface of the main body. A second member is attached to the first member. A through-hole is provided at a position of the second member. One surface of the second member includes a first area in contact with a surface opposite to the one surface of the first member and a second area located inside with respect to the first area. The second area is formed lower than a surface, of the first area, in contact with the surface opposite to the one surface. A lead-in electrode elastic member is disposed, in the second area, between the first member and second members.

A drive unit for driving an acceleration electrode of a mass spectrometer is disclosed. The drive unit includes a power converter comprising a switching element and pulsing circuitry that can form output pulses suitable for driving an acceleration electrode of a mass spectrometer. The drive unit also includes a controller that is configured to synchronise operation of the switching element with the pulsing circuitry.

The disclosure features methods and systems that include directing an ion beam to a region of a sample to liberate charged particles from the region of the sample, where the directed ion beam is pulsed at a first repetition rate, deflecting a first subset of the liberated charged particles from a first path to a second path different from the first path in response to a gate signal synchronized with the repetition rate of the pulsed ion beam, and detecting the first subset of the liberated charged particles in a time-of-flight (TOF) mass spectrometer to determine information about the sample, where the gate signal sets a common reference time for the TOF mass spectrometer for the first subset of charged particles liberated by each pulse of the ion beam.

A multi-reflecting time of flight mass analyser is disclosed in which the ion flight path is maintained relatively small and the duty cycle is made relatively high. Spatial focusing of the ions in the dimension (z-dimension) in which the mirrors (36) are elongated can be eliminated whilst maintaining a reasonably high sensitivity and resolution.

Systems and methods are disclosed for dynamically switching an ion guide and a TOF mass analyzer between concentrating or not concentrating ions in a targeted acquisition. Product ions are ejected from the ion guide into the TOF mass analyzer and the intensity of a known product ion is measured at two or more time steps. The ion guide initially ejects product ions using a sequential or Zeno pulsing mode that concentrates product ions with different m/z values within the TOF mass analyzer at the same time. If the intensity of the product ion is increasing and greater than a threshold intensity, the ion guide switches to a continuous or normal pulsing mode that does not concentrate ions with different m/z values in the TOF mass analyzer at the same time. Similarly, if the intensity decreases below a threshold in continuous mode, the ion guide switches back to sequential mode.

Methods for confirming charged-particle generation in an instrument are provided. A method to confirm charged-particle generation in an instrument includes providing electrical connections to a charged-particle optics system of the instrument while the charged-particle optics system is in a chamber. The method includes coupling an electrical component having an impedance to charged-particle current generated in the chamber. Moreover, the method includes measuring an electrical response by the electrical component to the charged-particle current. Related instruments are also provided.