Octopole ion guide

Fig. 14. Schematic representation of the high temperature octopole ion guide developed by Levandier et...

Fig. 1.6. Beam directioning during soft-landing the focusing octopole ion guide. The schematics present a 3D view of the newly constructed conical octopole guide. Eight rods shaped as truncated cone (diameter rejuvenates from 3 to 0.5 mm) are arranged in a conical geometry. Two Teflon plates at the ends with four carriage bolts and two metal collars (in the cylindrical part) keep the conical geometry. The ion entrance orifice opens 9 mm in iimer diameter and the exit focuses to around 2-mm spot size [74]...

The tandem MS includes a quadrupole mass filter, an octopole ion guide," a second quadrupole mass filter, and an ion detector. The ions from the flow tube are focused through electrostatic lenses into the first quadrupole, where a particular reactant ion is selected. These ions are then focused into the octopole, which passes through a cell that contains the collision gas. From the octopole, the dissociated and unreacted ions are focused into a second quadrupole for mass analysis. The detector is an electron multiplier operating in pulse-counting mode. 

Fig. 8. Schematic drawing tandem mass spectrometer in Z configuration for coaxial infrared laser excitation. Aperture lenses have been omitted for clarity. Comptonents (a) Nozzle, (b) skimmer, (c) electron gun, (d) and (i) quadrupole mass filter, (e) and (g) quadrupole deflector, (f) octopole ion guide, (h) CO2 laser, (j) ion conversion dynode, and (k) secondary eiectron multiplier. ...

This ion trap instrument has a chemical ionization source located orthogonally to an octopole ion guide, which admits fluoranthene anions formed in the chemical ionization source and transmits them to the entrance of the end-cap electrode [42], The positive polypeptide ions produced from ESI are admitted axially to the ion trap through the octopole ion guide and the entrance of the end-cap electrode. 

Electrospray ionization (ESI) Differential vacuum UHVchamber source and quadrupole mass filter and octopole ion guide with ion trap... 

Ions are typically injected axially through the entrance end-cap aperture of a QIT or axially through a lens element of a LQIT. It has been shown that ions can be injected and efficiently trapped directly from an octopole ion guide, despite having a significant... 

Figure 2.33 Plasma source quistor (PSQ). Schematic diagram of the vacuum interface, octopole ion guide/collision cell and the associated DC ion optics.

In essence, a guided-ion beam is a double mass spectrometer. Figure A3.5.9 shows a schematic diagram of a griided-ion beam apparatus [104]. Ions are created and extracted from an ion source. Many types of source have been used and the choice depends upon the application. Combining a flow tube such as that described in this chapter has proven to be versatile and it ensures the ions are thennalized [105]. After extraction, the ions are mass selected. Many types of mass spectrometer can be used a Wien ExB filter is shown. The ions are then injected into an octopole ion trap. The octopole consists of eight parallel rods arranged on a circle. An RF... 

The octopole configuration is similar to the quadrupole and hexapole in affording a good ion guidance system in its all-RF mode. The poles are connected in two pairs of four nonadjacent rods, and each pair is connected to an RF voltage supply, 180° out of phase with each other. The octopole is even more efficient than the hexapole as an ion guide. 

The efficiency of the ion guiding effect increases from quadrupole to hexapole to octopole. 

In a guided ion beam experiment, reactant ions are created in the source region, mass selected by a mass spectrometer (a magnetic sector in our instruments), decelerated to a desired kinetic energy, and injected into a radiofrequency (rf) octopole ion beam guide [10,11]. This device comprises eight rods cylindrically surrounding the ion beam path. Opposite phases of an rf potential... 

Fig. 1.35. Experimental setup for the investigation of gas-phase catalytic activity of mass-selected metal clusters. The cluster ions are sputtered from solid targets with a CORDIS, mass-selected (Qi), and guided at low energies (Qo and Q2) into the temperature controllable octopole ion trap. By means of appropriate switching of the lenses Li and L2, the reaction products are extracted and subsequently mass-analyzed by another quadrupole mass filter (Q3) [32,186]...

An octopole ion beam guide is being constructed, which will permit us to study collision energies down to 0.1 eV. In addition, we have made new position sensitive detectors, which will allow us to measure complete energy and angle differential cross sections. We anticipate that future results will be even more exciting than those we have described in this paper. 

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