Patent ID: 9159544
Filing Date: 2015-10-13
Classification: H01J

Abstract:
1. An electrostatic ion trap for mass analysis comprising: a first array of electrodes and a second array of electrodes, spaced from the first array of electrodes, voltage being supplied, in use, to electrodes of the first and second arrays of electrodes to create an electrostatic field in the space between the electrode arrays, wherein electrodes of the first array and electrodes of the second array are supplied, in use, with substantially the same pattern of voltage, whereby the distribution of electrical potential in said space is such as to reflect ions isochronously in a flight direction causing them to undergo periodic, oscillatory motion in said space, focused substantially mid-way between said first and second arrays, and wherein at least one electrode of said arrays is connected to amplifier circuitry for detection of image current having frequency components related to the mass-to-charge ratio of ions undergoing said periodic oscillatory motion in said space between the first and second arrays of electrodes and wherein said first and second arrays of electrodes each comprise concentric, circular or part-circular electrically conductive rings, and further including a full, or part-toroidal ion trap, or ion guide injector extending around said electrically conductive rings for respectively temporarily storing or guiding ions and then pulsing the ions radially inwards into said space between the first and second arrays of electrodes.