Patent ID: 11942318
Assignee: SHIMADZU CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 15:
16. A mass analyser for use in a mass spectrometer, the mass analyser having:
a set of sector electrodes spatially arranged to provide an electrostatic field in a 2D reference plane suitable for guiding ions along an orbit in the 2D reference plane, wherein the set of sector electrodes extend along a drift path that is locally orthogonal to the 2D reference plane so that, in use, the set of sector electrodes provide a 3D electrostatic field region; and
an extraction interface configured to extract ions out from the mass analyser via an extraction opening after the ions extracted out from the mass analyser have been guided by the 3D electrostatic field region along a 3D reference trajectory according to which ions perform multiple turns within the mass analyser whilst drifting along the drift path in a direction locally orthogonal to the 2D reference plane, wherein each turn as projected onto the 2D reference plane corresponds to a completed orbit in the 2D reference plane;
wherein the extraction interface includes at least one extraction deflector, located within the mass analyser, the at least one extraction deflector being configured to deflect ions following the 3D reference trajectory in the direction of the drift path, wherein the extraction deflector is configured to deflect ions following the 3D reference trajectory in the forward direction of the drift path so as to increase the distance between the 3D reference trajectory and the extraction opening such that the closest distance that the 3D reference trajectory comes to the extraction opening, when starting the last turn in the mass analyser, is larger than would have been the case had the at least one extraction deflector been absent so that ions guided along the 3D reference trajectory are, before extraction out from the mass analyser, deflected by the extraction deflector to be kept adequately distant from the extraction opening such that they are substantially unaffected by electric field distortions around the extraction opening.