Reverse geometry

A schematic diagram of a reverse geometry mass spectrometer is shown in figure Bl.7.4. 

Figure Bl.7.4. Schematic diagram of a reverse geometry (BE) magnetic sector mass spectrometer ion source (1) focusing lens (2) magnetic sector (3) field-free region (4) beam resolving slits (5) electrostatic sector (6) electron multiplier detector (7). Second field-free region components collision cells (8) and beam deflection electrodes (9).

Magnetic sectors can be used on their own, or in conjunction with energy analysers to fomi a tandem mass spectrometer. The unique features of the reverse geometry instrument are presented from this point. 

Figure Bl.7.5. (a) MIKE spectrum of the iinimoleciilar decomposition of 1-butene ions (m/z 56). This spectrum was obtained in the second field-free region of a reverse geometry magnetic sector mass...

Double-focusing reverse geometry ion optics is a combination in which the magnet is placed before the ESA, as shown in Figure 24.6. 

Mass spectrometer configuration. Multianalyzer instruments should be named for the analyzers in the sequence in which they are traversed by the ion beam, where B is a magnetic analyzer, E is an electrostatic analyzer, Q is a quadrupole analyzer, TOP is a time-of-flight analyzer, and ICR is an ion cyclotron resonance analyzer. For example BE mass spectrometer (reversed-geometry double-focusing instrument), BQ mass spectrometer (hybrid sector and quadrupole instrument), EBQ (double-focusing instrument followed by a quadrupole). 

Figure 1.1. Schematic of a double-focusing reverse geometry magnetic-sector instrument.

Figure 3.6 Schematics of three configurations of mass spectrometer capable of accurate mass measurement (a) forward-geometry (b) reverse-geometry (c) tri-sector. From applications literature published by Micromass UK Ltd, Manchester, UK, and reproduced with permission.

Mass-analysed ion kinetic energy spectrometry (MIKES) A form of MS-MS product-ion scan that may be carried out on a reversed-geometry double-focusing mass spectrometer. 

Reverse-geometry double-focusing mass spectrometer A double-focusing mass spectrometer in which the magnetic analyser precedes the electrostatic analyser. 

SFC Electron inpact (El) Reversed geometry (BE) Magnetic electron multiplier... 

Figure 2. Schematic view of reversed geometry double focusing mass spectrometer used for kinetic energy release measurements.

Figure 4-16 Reverse Geometry Capacitors for Lower Inductance...

Boyd, R.K. Porter, C.J. Beynon, J.H. A New Linked Scan for Reversed Geometry Mass Spectrometers. Org. Mass Spectrom. 1981,76,490-494. 

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