FIGS. 3A-3C and 4A-4C illustrate other examples of an analysis system 100.
As shown in FIGS. 3A and 4A, for example, the inlet device 15 can extend into a focusing electrode 48, shown as a tube electrode 48t, and be used in lieu of the accelerating and gate electrodes 28, 38 shown in FIGS. 1 and 2. The focusing electrode 48 can act as a “l(fā)ens” to focus the ions into the mass analyzer 30. The focusing electrode 48 can be operated with DC voltages to focus the ions. The focusing electrode 48 can have an inner diameter that is between about 3 and 6 mm and may have a length that is between 3-10 mm, typically about 5 mm. The focusing electrode 48 can be closely spaced apart from the front end of the mass analyzer 30 (e.g., the front endcap electrode of an ion trap), typically by about 0.1 mm to about 2 mm, such as about 0.1 mm, about 0.2 mm, about 0.3 mm, about 0.4 mm, about 0.5 mm, about 0.6 mm, about 0.7 mm, about 0.8 mm, about 0.9 mm, about 1 mm, about 1.1 mm, about 1.2 mm, about 1.3 mm, about 1.4 mm, about 1.5 mm, about 1.6 mm, about 1.7 mm, about 1.8 mm, about 1.9 mm, and about 2 mm, in some embodiments.
In some embodiments, the internal end of the inlet device 15i can be positioned to reside inside the focusing electrode 48 a short distance of between about 0.1 mm to about 1 mm, typically between about 0.2 mm, about 0.3 mm, about 0.4 mm or about 0.5 mm, for example.
