A system for separating ions may include an ion source configured to generate ions from a sample, at least one ion separation instrument configured to separate the generated ions as a function of at least one molecular characteristic, and an orbitrap in which a rotating and oscillating ion induces charges on inner and outer electrode halves of the orbitrap, and wherein charge detection circuitry is configured to detect the charges induced on each of the inner electrode halves and on each of the outer electrode halves, and to combine the detected charges for each oscillation to produce a measured ion charge signal.

A multipole ion guide includes a plurality of electrodes disposed about a longitudinal axis of the device so as to define an ion transmission volume for transmitting ions along a length of the device between opposite inlet and outlet ends. An electronic controller is operably connected to an RF power source and to at least some of the electrodes and is configured to apply at least an RF potential to the electrodes. During use the electrodes generate an RF-only field along a first portion of the device and an axial DC field along a second portion of the device. Ions are focused radially inward toward the longitudinal axis of the device by the RF-only field within the first portion of the device prior to and/or subsequent to experiencing the axial DC field within the second portion of the device.

A miniature electrode apparatus is disclosed for trapping charged particles, the apparatus including, 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.

Four rod electrodes (50a to 50d) for separating ions according to a mass-to-charge ratio are held by a rod holder (51). The rod holder (51) is placed on a metal holder sustaining stand (52) provided on a bottom surface of a vacuum housing (1), and is fixed while being pressed by a fixation band (53) fixed to the holder sustaining stand (52) with screws (56). The fixation band (53) is made from phosphor bronze having higher thermal conductivity than thermal conductivity of stainless steel or the like. Therefore, heat generated in the rod holder (51) due to dielectric loss is not only directly transmitted to the holder sustaining stand (52), but also efficiently transmitted to the holder sustaining stand (52) through the fixation band (53). With this, the heat of the rod holder (51) is efficiently dissipated, and non-uniformity of temperature of the rod holder can be reduced.

An octa-electrode linear ion trap mass analyzer is formed by eight cylindrical electrodes and at least two end-cap electrodes. The inside surfaces of the eight cylindrical electrodes are free-form. The material of the octa-electrode linear ion trap mass analyzer is a conductive metal material or an insulating material plated with a conductive coating. The eight cylindrical electrodes are divided into four groups of cylindrical electrodes in total, each group of the four groups of cylindrical electrodes comprises two cylindrical electrodes, and each two groups of the four groups of cylindrical electrodes are parallelly placed. At least one through hole is provided with in the center of the end-cap electrode, and the two end-cap electrodes are respectively arranged at both ends of the cylindrical electrode.

Four rod electrodes (50a to 50d) for separating ions according to a mass-to-charge ratio are held by a rod holder (51). The rod holder (51) is placed on a metal holder sustaining stand (52) provided on a bottom surface of a vacuum housing (1), and is fixed while being pressed by a fixation band (53) fixed to the holder sustaining stand (52) with screws (56). The fixation band (53) is made from phosphor bronze having higher thermal conductivity than thermal conductivity of stainless steel or the like. Therefore, heat generated in the rod holder (51) due to dielectric loss is not only directly transmitted to the holder sustaining stand (52), but also efficiently transmitted to the holder sustaining stand (52) through the fixation band (53). With this, the heat of the rod holder (51) is efficiently dissipated, and non-uniformity of temperature of the rod holder can be reduced.

A first multipole assembly includes a first plurality of rod electrodes arranged about an axis and configured to confine ions radially about the axis. A second multipole assembly disposed adjacent to the first multipole assembly includes a second plurality of rod electrodes arranged about the axis and configured to confine the ions radially about the axis. An orientation of the first multipole assembly about the axis is rotationally offset relative to an orientation of the second multipole assembly about the axis.

An ion guide is disclosed that comprises a plurality of electrodes arranged to form a multipole ion guide and one or more rigid support members. The plurality of electrodes comprises one or more groups of electrodes, and each group of electrodes comprises plural electrodes that are axially spaced apart from one another. The electrodes of one or more groups of electrodes are attached to one of the one or more rigid support members. One or more of the electrodes comprises a curved metal sheet, plate or strip.

Disclosed herein is an ion guide for guiding an ion beam along an ion path, said ion guide having a longitudinal axis corresponding to said ion path, said ion guide-comprising a plurality of elongate electrodes arranged around and extending along said longitudinal axis wherein an inner envelope of the plurality of electrodes defines an ion guide volume. Said elongate electrodes are formed by electrode wires, wherein adjacent electrode wires are arranged at an inter-wire distance. The ion guide comprises holding structures for supporting and for straightening the electrode wires by applying a tension or maintaining a tension applied to them. Any portion of said holding structures which is separated from said ion guide volume by less than the local inter-wire distance is made from a material having a resistivity of less than 10.sup.12 Ohm.Math.cm, preferably of less than 10.sup.9 Ohm.Math.cm, or has a sheet resistivity of less than 10.sup.14 Ohm, preferably of less than 10.sup.10 Ohm on a surface facing said ion guide volume.

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.