A Time of Flight mass analyser 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. An ion detector is disposed within the annular ion guide. Ions are orthogonally accelerated in a first axial direction from the first annular ion guide section into the second annular ion guide section. An axial DC potential is maintained along at least a portion of the second annular ion guide section so that the ions are reflected in a second axial direction which is substantially opposed to the first axial direction. The ions undergo multiple axial passes through the second annular ion guide section before being detected by the ion detector.

An ion mirror (10) for use in a time of flight mass spectrometer (100) comprises a first conductor (20) for producing a quadratic field along a first axis (80), and a second conductor (30) for producing a quadratic field along a second axis (90), the axes (80, 90) being orthogonal.

A method of separating ions according to a physicochemical property is disclosed. The method comprises causing ions to perform a plurality of cycles along or around an ion guiding path such that the ions separate according to said physicochemical property. The ions are ejected from an ion exit region by applying a force to the ions such that only having a physicochemical property value that is either above or below a threshold value are ejected as they pass through the exit region, but ions having a physicochemical property value either below or above said threshold value, respectively, remain within the ion guiding path. The force applied to the ions within the exit region is varied with time such that the physicochemical property value of the ions ejected from the ion guiding region varies with time.

An electrostatic ion trap for mass analysis includes a first array of electrodes and a second array of electrodes, spaced from the first array of electrode. The first and second arrays of electrodes may be planar arrays formed by parallel strip electrodes or by concentric, circular or part-circular electrically conductive rings. The electrodes of the arrays are supplied with substantially the same pattern of voltage whereby the distribution of electrical potential in the space between the arrays is such as to reflect ions isochronously in a flight direction causing them to undergo periodic, oscillatory motion in the space, focused substantially mid-way between the arrays. Amplifier circuitry is used to detect image current having frequency components related to the mass-to-charge ratio of ions undergoing the periodic, oscillatory motion.

A system for expressing an ion path in a time-of-flight (TOF) mass spectrometer. The present invention uses two successive curved sectors, with the second one reversed, to form S-shaped configuration such that an output ion beam is parallel to an input ion beam, such that the ions makes two identical but opposed turns, and such that the geometry of the entire system folds into a very compact volume. Geometry of a TOF mass spectrometer system in accordance with embodiments of the present invention further includes straight drift regions positioned before and after the S-shaped configuration and, optionally, a short straight region positioned between the two curved sectors with total length equal to about the length of the central arc of both curved sectors.

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. An ion detector is disposed within the annular ion guide. Ions are orthogonally accelerated in a first axial direction from the first annular ion guide section into the second annular ion guide section. An axial DC potential is maintained along at least a portion of the second annular ion guide section so that the ions are reflected in a second axial direction which is substantially opposed to the first axial direction. The ions undergo multiple axial passes through the second annular ion guide section before being detected by the ion detector.

A method of separating ions according to a physicochemical property is disclosed. The method comprises causing ions to perform a plurality of cycles along or around an ion guiding path such that the ions separate according to said physicochemical property. The ions are ejected from an ion exit region by applying a force to the ions such that only having a physicochemical property value that is either above or below a threshold value are ejected as they pass through the exit region, but ions having a physicochemical property value either below or above said threshold value, respectively, remain within the ion guiding path. The force applied to the ions within the exit region is varied with time such that the physicochemical property value of the ions ejected from the ion guiding region varies with time.

An electrostatic ion trap for mass analysis includes a first array of electrodes and a second array of electrodes, spaced from the first array of electrode. The first and second arrays of electrodes may be planar arrays formed by parallel strip electrodes or by concentric, circular or part-circular electrically conductive rings. The electrodes of the arrays are supplied with substantially the same pattern of voltage whereby the distribution of electrical potential in the space between the arrays is such as to reflect ions isochronously in a flight direction causing them to undergo periodic, oscillatory motion in the space, focused substantially mid-way between the arrays. Amplifier circuitry is used to detect image current having frequency components related to the mass-to-charge ratio of ions undergoing the periodic, oscillatory motion.

A basic ion optical system having a guaranteed capability for the temporal focusing of ions, including sector-shaped electrodes, an injection slit and an ejection slit, is arranged on the same plane. Four or more sets of the basic ion optical systems are arrayed at predetermined intervals in a direction substantially orthogonal to the aforementioned plane. The injection slit on a topmost basic ion optical system plane and the ejection slit on a basic ion optical system plane located immediate below, as well as the injection slit on a bottommost basic ion optical system plane and the ejection slit on a basic ion optical system plane located immediate above, are respectively connected by another type of basic ion optical system having a guaranteed capability for the temporal focusing of ions. The other injection slits and ejection slits are respectively connected by another type of basic ion optical system having a guaranteed capability for the temporal focusing of ions. Thus, a loop orbit having a three-dimensionally deformed figure 8-shape is formed, whereby the flight distance is elongated while ensuring the temporal focusing of the ions for the entire system, simultaneously with utilizing the three-dimensional space to compactify the ion optical system.

A method of introducing and ejecting ions from an ion entry/exit device (4) is disclosed. The ion entry/exit device (4) has at least two arrays of electrodes (20,22). The device is operated in a first mode wherein DC potentials are successively applied to successive electrodes of at least one of the electrode arrays ((20,22) in a first direction such that a potential barrier moves along the at least one array in the first direction and drives ions into and/or out of the device in the first direction. The device is also operated in a second mode, wherein DC potentials are successively applied to successive electrodes of at least one of the electrode arrays (20,22) in a second, different direction such that a potential barrier moves along the array in the second direction and drives ions into and/or out of the device in the second direction. The device provides a single, relatively simple device for manipulating ions in multiple directions. For example, the device may be used to load ions into or eject ions from an ion mobility separator in a first direction, and may then be used to cause ions to move through the ion mobility separator in the second direction so as to cause the ions to separate.