Grounded ring electrodes

GROUND ROD, COLD WATER PIPE, BUILDING STEEL GROUND RING, CONCRETE ENCASED ELECTRODE ETC. 

The ion trap generally consists of three electrodes, one ring electrode with a hyperbolic inner surface and two hyperbolic endcap electrodes at either end (a cross section of an ion trap is found in Figure 1.11). The ring electrode is operated with a sinusoidal radio frequency field while the endcap electrodes are operated in one of three modes. The endcap may be operated at ground potential, or with either a DC or an AC voltage. 

The electrodes in Figure 2 are truncated for practical purposes but, in theory, they extend to infinity and meet the asymptotes shown. The electrode geometries are defined so that, when an RF potential is applied to the ring electrode with the end-cap electrodes grounded, a near-ideal quadrupole field is produced, which creates a parabolic potential well for ion confinement. Figure 3. As shown in Figure 3, the potential well in the axial directioims of depth D, while that in the radial direction D ] since 2Dr, the potential well resembles more a flower vase than a bowl. 

Fig. 8. Magnetherm reactor central electrode, A secondary circuit, B grounding electrode, C refractory lining, D carbon lining, E primary material feed, F slag taphole to FeSi recovery, G vacuum line, H water spray ring, I condenser, cmcible, K trap, L filter, M and transformer, N.

FIG. 24. The deposition rate at the grounded electrode with the contribution of each silicon-containing species, for a large scale reactor with (a) ring inlet and (b) showerhead inlet. Note the difference in uniformity. Discharge settings are a total pressure of 20 Pa. a power of 5 W, and an RF frequency of 50 MHz. (From G. J. Nienhuis, Ph.D. Thesis, Univcrsiteit Utrecht, Utrecht, the Netherlands, 1998, with permission.)... 

In most commercial cylindrical ion trap instalments the end-cap electrodes are held at ground potential and usually only a RF potential is applied to the ring electrode. When the RF amplitude is set to a low, so-called storage voltage, all ions above a certain m/z are trapped. This voltage is usually chosen so the lowest trapped m/z is greater than those of water, air, and solvent ions (i.e., above 100 to 150 Th), depending on the nature of the measured species. 

Traditional 3D quadrupole ion traps utilize three electrodes two end caps and a ring electrode. The end caps are usually at ground potential and a RF voltage is applied to the ring electrode to generate a quadmpole field to store ions. Helium gas is present in the trap at a pressure of 1 mtorr to cool the ions and improve... 

Figure 6.20 Flow cell with horizontal DME for continuous monitoring (a) sample introduction tube (b) solution outlet (c) DME capillary (d) O-ring seals (e) waste mercury (/) agar salt bridge to counter electrode (g) SCE reference electrode with agar plug and fine glass frit (h) ground-glass joints.

The ion trap mass analyzer [2] (Fig. 2) consists of two end-cap electrodes, held at ground potential, and an interposed ring electrode, to which DC and RF voltages are applied. The ring electrode is a single surface formed by a hyperboloid of rotation. The end-caps are complementary hyperboloids having the same conical asymptotes z is an axis of... 

The quadrupole ion trap is a three-dimensional (3-D) analog of the linear quadrupole [33]. It consists of two end-cap electrodes with hyperbolic cross sections and one ring electrode located between the end caps (Figure 7-5B). The RF voltage is applied to the ring electrode and the ground potential is normally operated on the end caps. A rotationally symmetric electric... 

---