| 摘要 |
A method of separating ions by providing an analyser comprising two opposing ion mirrors 40, 50 each mirror comprising inner 20 and outer 30 field-defining electrode systems elongated along an analyser axis z wherein the outer field-defining electrode system 30 surrounds the inner field-defining electrode system 20. Therebetween an analyser volume 60 is created. Ions are injected into the analyser volume or created within the analyser volume so that they separate according to their time of flight as they travel along a main flight path. Whilst travelling along this flight path they undergo a plurality of axial oscillations in the direction of the analyser axis z and a plurality of radial oscillations whilst orbiting about one or more inner field-defining electrodes 20. The plurality of axial oscillations and plurality of radial oscillations cause the separated ions to intercept an exit port 70, 80 after a predetermined number of orbits. An analyser for performing the method is also described comprising the two opposing ion mirrors (Fig. 4, 420, 410) which abut at a first plane (p1). The outer field-defining electrode system of one mirror (410) comprises two sections (452, 454) the sections abutting at a second plane (p2) and comprising a first section (452) between the first plane (p1) and the second plane (p2) and a second section (454) adjacent the first section (452). The first section (452) has at least a portion (453) which extends radially from the analyser axis (z) to a greater extent than an adjacent portion (455) of the second section (454) at the second plane (p2). |
