Forward-geometry double-focusing mass

Forward-geometry double-focusing mass spectrometer A double-focusing... 

Like the P54, the Nu Plasma is a forward geometry double-focusing mass spectrometer with double dispersion, but it has the standard C configuration and defines a smaller footprint (Fig. 8.2). The instrument has a source that is similar to... 

Schematic diagram of an electric and a magnetic sector as they are arranged in a forward geometry double-focusing mass spectrometer (Nier-Johnson geometry). (Reprinted from Ref. 7 with permission of John V ffley Sons)...

When the first quadrupole of a triple quadrupole is replaced by a double-focusing mass spectrometer, the instrument is termed a hybrid (i.e. a hybrid of magnetic sector and quadrupole technologies). Figure 3.9 shows the MSi unit as a forward-geometry instrument although there is no reason why this could not be of reversed- or even tri-sector geometry. 

Figure 3 Modified Nier-Johnson -type double-focusing magnetic sector mass spectrometer (A) with forward geometry, (B) with reverse geometry, (C) with split forward and reverse geometry.

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