An ion guide (40) is disclosed that comprises an ion confinement region having a first cross-sectional profile with a first cross-sectional area A1 in a plane orthogonal to a direction of ion transmission. An attenuation device ejects or deflects ions having spatial positions which fall outside of a second cross-sectional profile having a second cross-sectional area A2, wherein A2<A1.

An electrode assembly, such as for an ion mirror, comprising: a first layer having a plurality of electrodes that are separated by one or more gaps; a second layer arranged to cover said one or more gaps and prevent electric fields passing through said one or more gaps, said second layer having electrically conductive material located to be coincident with said one or more gaps in the first layer.

A method of operating a quadrupole device is disclosed that comprises operating the quadrupole device in a first mode of operation, passing ions into the quadrupole device while the quadrupole device is operated in the first mode of operation, and then operating the quadrupole device in a second mode of operation. Operating the quadrupole device in the second mode of operation comprises applying one or more drive voltages to the quadrupole device, and operating the quadrupole device in the first mode of operation comprises applying one or more reduced drive voltages or not applying one or more drive voltages to the quadrupole device.

The present invention relates to a reaction chamber (12) for an IMR-MS apparatus or a PTR-MS apparatus, comprising an essentially gaslight outer housing (14), comprising at least two ion lenses (16) with essentially constant orifice dimensions and/or at least two ion lenses (17) with different orifice dimensions arranged around the reaction region (20), and at least one at least partly gaslight sealing (19), characterized in that the ion lenses (16,17) are placed inside the essentially gaslight outer housing (14), wherein between at least two adjacent ion lenses (16,17) an at least partly gaslight sealing (19) is mounted, wherein the room between at least other two ion lenses (16, 17) is such to allow a gas flow through said room from the reaction region (20) into the outer space (21). The present invention further relates to a method to operate an apparatus according to the invention.

An apparatus for transporting charged particles. The apparatus includes a control unit and a transport device having a plurality of electrodes arranged around a transport channel, wherein the transport channel includes a bunch forming region configured to receive charged particles received by the transport device. The control unit is configured to control voltages applied to the electrodes to generate a transport potential in the transport channel, the transport potential having a plurality of potential wells which are configured to move so as to transport charged particles along the transport channel in one or more bunches. The control unit is further configured to control voltages applied to the electrodes: temporarily generate a gathering potential in the bunch forming region so that charged particles received by the transport device are gathered in the bunch forming region; and then generate the transport potential in the bunch forming region so that a selected potential well is formed in the bunch forming region with the selected potential well receiving a bunch of charged particles formed from the charged particles gathered in the bunch forming region by the gathering potential.

Disclosed herein is an ion guide for guiding an ion beam along an ion path, said ion guide having a longitudinal axis which corresponds to said ion path. Said ion guide comprises a plurality of electrode plates which are arranged perpendicularly to the longitudinal axis, each electrode plate having an opening and being arranged such that said longitudinal axis extends through its respective opening, wherein said openings collectively define an ion guide volume. The ion guide extends or is configured to extend through a separation wall separating adjacent first and second pumping chambers. The ion guide has a first portion, in which gaps are formed between at least some of said electrode plates such that uncharged gas can escape from said ion guide volume, wherein said first portion is completely located in said first pumping chamber. A second portion, in which sealing elements are arranged between adjacent electrode plates, prevents neutral gas from escaping from that portion of the ion guide volume between adjacent electrode plates, said second portion extends at least from said separation wall into said second pumping chamber.

A miniature electrode apparatus is disclosed for trapping charged particles, the apparatus includes, along a longitudinal direction, a first end cap electrode, a central electrode having an aperture, and a second end cap electrode. The aperture is elongated in the lateral plane and extends through the central electrode along the longitudinal direction and the central electrode surrounds the aperture in a lateral plane perpendicular to the longitudinal direction to define a transverse cavity for trapping charged particles. Electric fields can be applied in a y-direction of the lateral plane across one or more planes perpendicular to the longitudinal axis to translocate and/or manipulate ion trajectories.

An ion optical arrangement (1) for use in a mass spectrometer comprises a collision cell defining an ion optical axis along which ions may pass, electrodes comprising a set of parallel poles (11A, 11B, 11C) arranged in the collision cell, and a voltage source for providing voltages to the electrodes to produce electric fields. The ion optical arrangement is arranged for switching between a first operation mode in which the collision cell is pressurized and a second operation mode in which the collision cell is substantially evacuated. The ion optical arrangement is further arranged for producing a radio frequency electric focusing field in the first operation mode and a static electric focusing field in the second operation mode.

An ion guide with a switchable ion path for a spectrometer includes a first ion transport aperture configured to receive an ion beam. A radio frequency surface comprises a plurality of radio frequency electrodes arranged on a first surface, such that the radio frequency electrodes are parallel. A radio frequency voltage source is configured to apply an alternating radio frequency phase to each radio frequency electrode. A DC potential source is configured to apply a DC gradient across the radio frequency surface. The DC gradient is configured to guide an ion beam via either a first ion path or a second ion path. Ions travelling in the first ion path are directed between the first ion transport aperture and a second ion transport aperture. Ions travelling in the second ion path are directed between the first ion transport aperture and a third ion transport aperture.

One or more ions are received along a central axis through a first set of reflectron plates of an ELIT. Voltages are applied to the first set of plates and to a second set of reflectron plates in order to trap and oscillate the one or more ions. A first induced current is measured from a cylindrical pickup electrode between the first set of reflectron plates and the second set of reflectron plates. A second induced current is measured from one or more plates of the first set of reflectron plates. A third induced current is measured from one or more plates of the second set of reflectron plates. The first measured induced current, second measured induced current and third measured induced current are combined to reduce higher order frequency harmonics of the induced current.