Tandems, electrostatic

The Application of Electrostatic Tandems to Ultrasensitive Mass Spectrometry and Nuclear Dating... 

Purser, K. H., Russo, C. J., Liebert, R. B., Gove, H., Elmore, D., Ferraro, R., Litherland, A. E., Beukens, R., Chang, K., Kilius, L, Lee, H., The Application of Electrostatic Tandems to Ultra-sensitive Mass Spectrometry and Nuclear Dating, Chapter 3 in this book. 

One of the largest Van de Graaff-type accelerators is the Holifield Heavy Ion Accelerator at Oak Ridge National Laboratory in Tennessee. It uses 0.7 MPa of SFe as an insulating gas. With this machine a dc voltage of 34 MV was achieved. A view of this electrostatic tandem-type heavy ion accelerator is shown in Fig. 11. 

A more advanced mirror approach involving multicells, called the tandem mirror, has been studied as a means to overcome the leakage problem. One way to view the tandem mirror is as a long uniform magnetic solenoid with two single-cell mirrors installed at the ends to electrostatically plug the device. Plasma end losses ate impeded by electrostatic potentials developed by the plasma as the electrons and ions attempt to leave the device at different rates. 

Various tandem MS instrument configurations have been developed, e.g. sector instruments, such as CBCE, CBCECB or CECBCE, and hybrid instruments, e.g. BCECQQ (B = magnetic sector analyser, E = electrostatic analyser, C = collision cell, Q = quadrupole mass spectrometer), all with specific performance. Sector mass spectrometers have been reviewed [168],... 

Principles and Characteristics Particle-induced X-ray emission spectrometry (PIXE) is a high-energy ion beam analysis technique, which is often considered as a complement to XRF. PIXE analysis is typically carried out with a proton beam (proton-induced X-ray emission) and requires nuclear physics facilities such as a Van der Graaff accelerator, or otherwise a small electrostatic particle accelerator. As the highest sensitivity is obtained at rather low proton energies (2-4 MeV), recently, small and relatively inexpensive tandem accelerators have been developed for PIXE applications, which are commercially available. Compact cyclotrons are also often used. 

Widespread interest has developed during the last few years in a new analytical technique which uses a tandem electrostatic acclerator as one element of a double mass spectrometer [1-19]1. With this technique, individual atoms of many nuclear species from most areas of the periodic table can be identified with good efficiency and in the presence of an almost zero background of unwanted atoms and molecular species of the same mass. 

Electrostatic sector field equilibr electrostatic force and centrifugal force e-E0 = — 2 - energy focusing 50 double-focusing sector field ms, tandem ms... 

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