Abstract: A method of analysing ions comprises separating ions according to a first physico-chemical property by passing the ions through an ion separation device, and measuring the transit time of an ion through the ion separation device. The method further comprises detecting the ion using a charge-resolving ion detector so as to determine the charge of the ion, and using the transit time and the charge of the ion to determine a second physico-chemical property of the ion.

Abstract: A method of analysing high-mass (>1 MDa) particles comprises ionising particles to as to produce ions, separating the ions according to mass to charge ratio by passing the ions through an ion separation device in which one or more time-varying electric fields is used to urge ions through a gas such that ions are separated according to mass to charge ratio, measuring the transit time of the ions through the ion separation device, and determining a drift time or mass to charge ratio distribution of the ions therefrom. The method further comprises identifying one or more charge envelopes in the drift time or mass to charge ratio distribution, and using the one or more charge envelopes to characterise the particles.

Abstract: A method of operating a quadrupole device is disclosed. The method comprises operating the quadrupole device in a first mode of operation, wherein ions within a first mass to charge ratio range are selected and/or transmitted by the quadrupole device, and operating the quadrupole device in a second mode of operation, wherein ions within a second different mass to charge ratio range are selected and/or transmitted by the quadrupole device. In the first mode of operation, the quadrupole device is operated in a normal mode of operation wherein a main drive voltage is applied to the quadrupole device, or in a first X-band or Y-band mode of operation wherein a main drive voltage and two or more auxiliary drive voltages are applied to the quadrupole device. In the second mode of operation, the quadrupole device is operated in a second X-band or Y-band mode of operation wherein a main drive voltage and two or more auxiliary drive voltages are applied to the quadrupole device.

Abstract: A method of operating a quadrupole device is disclosed. The method comprises applying a main drive voltage to the quadrupole device and applying three or more auxiliary drive voltages to the quadrupole device. The three or more auxiliary drive voltages correspond to two or more pairs of X-band or Y-band auxiliary drive voltages.

Abstract: A method of operating a quadrupole device is disclosed. The method comprises operating the quadrupole device in a first mode of operation, wherein ions within a first mass to charge ratio range are selected and/or transmitted by the quadrupole device, and operating the quadrupole device in a second mode of operation, wherein ions within a second different mass to charge ratio range are selected and/or transmitted by the quadrupole device. In the first mode of operation, the quadrupole device is operated in a normal mode of operation wherein a main drive voltage is applied to the quadrupole device, or in a first X-band or Y-band mode of operation wherein a main drive voltage and two or more auxiliary drive voltages are applied to the quadrupole device. In the second mode of operation, the quadrupole device is operated in a second X-band or Y-band mode of operation wherein a main drive voltage and two or more auxiliary drive voltages are applied to the quadrupole device.

Abstract: A method of operating a quadrupole device is disclosed. The method comprises applying a main drive voltage to the quadrupole device and applying three or more auxiliary drive voltages to the quadrupole device. The three or more auxiliary drive voltages correspond to two or more pairs of X-band or Y-band auxiliary drive voltages.

Abstract: A mass filter is disclosed having at least one electrode (42-48) comprising an aperture (43) or recess. Voltages are applied to the electrodes (42-48) of the mass filter such that ions having mass to charge ratios in a desired range are confined by the electrodes and are transmitted along and through the mass filter, whereas ions (47,49) having mass to charge ratios outside of said desired range are unstable and pass into the aperture (43) or recess such that they are filtered out by the mass filter. The aperture (43) or recess reduces or eliminates the number of ions that would otherwise impact the electrode surface facing the ion transmission axis and hence reduces degradation of the ion transmission properties of the mass filter.

Abstract: A mass filter is disclosed having at least one electrode (42-48) comprising an aperture (43) or recess. Voltages are applied to the electrodes (42-48) of the mass filter such that ions having mass to charge ratios in a desired range are confined by the electrodes and are transmitted along and through the mass filter, whereas ions (47,49) having mass to charge ratios outside of said desired range are unstable and pass into the aperture (43) or recess such that they are filtered out by the mass filter. The aperture (43) or recess reduces or eliminates the number of ions that would otherwise impact the electrode surface facing the ion transmission axis and hence reduces degradation of the ion transmission properties of the mass filter.

Abstract: A mass filter is disclosed having at least one electrode (42-48) comprising an aperture (43) or recess. Voltages are applied to the electrodes (42-48) of the mass filter such that ions having mass to charge ratios in a desired range are confined by the electrodes and are transmitted along and through the mass filter, whereas ions (47,49) having mass to charge ratios outside of said desired range are unstable and pass into the aperture (43) or recess such that they are filtered out by the mass filter. The aperture (43) or recess reduces or eliminates the number of ions that would otherwise impact the electrode surface facing the ion transmission axis and hence reduces degradation of the ion transmission properties of the mass filter.

Abstract: A mass filter is disclosed having at least one electrode (42-48) comprising an aperture (43) or recess. Voltages are applied to the electrodes (42-48) of the mass filter such that ions having mass to charge ratios in a desired range are confined by the electrodes and are transmitted along and through the mass filter, whereas ions (47,49) having mass to charge ratios outside of said desired range are unstable and pass into the aperture (43) or recess such that they are filtered out by the mass filter. The aperture (43) or recess reduces or eliminates the number of ions that would otherwise impact the electrode surface facing the ion transmission axis and hence reduces degradation of the ion transmission properties of the mass filter.

Abstract: An ion guide is disclosed wherein an axial DC voltage barrier is created at the exit of the ion guide. A primary RF voltage is applied to the electrodes in order to confine ions radially within the ion guide. A supplemental RF voltage is also applied to the electrodes. The supplemental RF voltage has a greater axial repeat length than that of the primary RF voltage. The amplitude of the supplemental RF voltage is increased with time causing ions to become unstable and gain sufficient axial kinetic energy such that the ions overcome the axial DC voltage barrier. Ions emerge axially from the ion guide in mass to charge ratio order.

Abstract: An ion guide is disclosed wherein an axial DC voltage barrier is created at the exit of the ion guide. A primary RF voltage is applied to the electrodes in order to confine ions radially within the ion guide. A supplemental RF voltage is also applied to the electrodes. The supplemental RF voltage has a greater axial repeat length than that of the primary RF voltage. The amplitude of the supplemental RF voltage is increased with time causing ions to become unstable and gain sufficient axial kinetic energy such that the ions overcome the axial DC voltage barrier. Ions emerge axially from the ion guide in mass to charge ratio order.

Abstract: A mass spectrometer is disclosed comprising a quadrupole rod set ion trap wherein a potential field is created at the exit of the ion trap which decreases with increasing radius in one radial direction. Ions within the ion trap are mass selectively excited in a radial direction. Ions which have been excited in the radial direction experience a potential field which no longer confines the ions axially within the ion trap but which instead acts to extract the ions and hence causes the ions to be ejected axially from the ion trap.

Abstract: An ion guide array is disclosed comprising a first ion guide section and a second ion guide section and optionally further ion guide sections. Each ion guide section may comprise a plurality of electrodes having an aperture through which ions are transmitted in use. A transfer section is arranged at the exit of the first ion guide section and ions are transmitted radially from the first ion guide section into the second ion guide section. The electrodes in the transfer section may have a radial aperture enabling ions to be transmitted radially from the first ion guide section to the second ion guide section.

Abstract: A linear ion trap (6, 7, 8)is disclosed comprising a central quadrupole rod set (6)and a post-filter quadrupole rod set (8). A 180° phase difference is maintained between axially adjacent rod electrodes of the central quadrupole rod set (6) and the post-filter quadrupole (8) so that an axial pseudo-potential barrier is created between the central quadrupole rod set (6) and the post-filter quadrupole (8). A supplementary AC voltage is applied to the rods of the central quadrupole (6) in order to radially excite ions which are desired to be ejected from the ion trap. The ions are ejected from the ion trap (6, 7, 8) non-adiabatically in an axial direction.

Abstract: An ion guide array is disclosed comprising a first ion guide section (1) and a second ion guide section (2) and optionally further ion guide sections. Each ion guide section (1, 2) may comprise a plurality of electrodes having an aperture through which ions are transmitted in use. A transfer section is arranged at the exit of the first ion guide section (1) and ions are transmitted radially from the first ion guide section (1) into the second ion guide section (2). The electrodes (1b, 2b) in the transfer section may have a radial aperture enabling ions to be transmitted radially from the first ion guide section (1) to the second ion guide section (2).

Abstract: A linear ion trap (6,7,8)is disclosed comprising a central quadrupole rod set (6)and a post-filter quadrupole rod set (8). A 180° phase difference is maintained between axially adjacent rod electrodes of the central quadrupole rod set (6) and the post-filter quadrupole (8) so that an axial pseudo-potential barrier is created between the central quadrupole rod set (6) and the post-filter quadrupole (8). A supplementary AC voltage is applied to the rods of the central quadrupole (6) in order to radially excite ions which are desired to be ejected from the ion trap. The ions are ejected from the ion trap (6,7,8) non-adiabatically in an axial direction.

Abstract: A mass spectrometer is disclosed comprising a quadrupole rod set ion trap (2, 3) wherein a potential field is created at the exit of the ion trap (4, 5) which decreases with increasing radius in one radial direction. Ions within the ion trap (2, 3) are mass selectively excited in a radial direction. Ions which have been excited in the radial direction experience a potential field which no longer confines the ions axially within the ion trap but which instead acts to extract the ions and hence causes the ions to be ejected axially from the ion trap (2, 3).

Abstract: An optical communications network uses tandem connection monitoring for monitoring errors introduced by a sub-network. The sub-network nodes are provided with a sub-network monitoring arrangement, and when the sub-network monitoring arrangement identifies a fault, an internal alarm indication indicative of a fault is provided as the error information. The tandem connection monitoring arrangement, upon receipt of data with the internal alarm indication, replaces the internal alarm indication with a general fault indication. The network of the invention has two levels of alarm indication. One is for identifying a fault in a preceding sub-network, and the other is for identifying a fault internal to a TCM monitoring section. This enables path alarm flooding to be avoided.

Abstract: A continuous motion converter for converting rotary motion to reciprocatory motion and/or reciprocatory motion to rotary motion. A pair of wheels are positioned in a spaced co-planar relationship to each other and have an endless flexible drive member received over them. A carrier is located about the outer perimeter of the drive member. The drive member supports at one location thereon a slider which extends across the outer width of the drive member. The slider is slidably received on the carrier to extend to each side thereof for movement with the drive member and transverse movement relative to the axis extending between the wheels whereby with movement of the drive member over the wheels the carrier reciprocates between the wheels and the slider reciprocates transversely on the carrier, support means being provided to support the slider within the carrier continuously throughout movement of the carrier.