Tandem electrostatic accelerators

The relevant energy levels of Mg10+ are shown in fig. 1. The experimental arrangement, see fig. 2, was similar to that described in refs. [14,15], A nominally 50.3 MeV beam of 24Mg6+, v/c 0.067, was obtained from the Florida State University tandem electrostatic accelerator and momentum analyzed in a 90° bending magnet. The analyzed beam, current 5-10 particle-nA, was focused to a diameter of approx. 1.25 mm and passed through a 4 or 10 fig cm-2 carbon foil in... 

Instrumentation. HPLC isolations were performed on a Beckman 421A system using a Vydac column (C-18, 4.6 x 250 mm). Liquid secondary ion mass spectra (LSIMS) were recorded in the positive ion mode on a Kratos (Manchester, UK) MS-50S mass spectrometer equipped with a 23 kG magnet and post-acceleration detector. The LSIMS ion source has been described elsewhere (28). A Cs+ ion beam of energy 10 keV was used as the primary beam (21). Spectra were recorded (300 sec per decade) with a Gould ES-1000 electrostatic recorder. Tandem MS experiments were performed on a Kratos Concept IIHH (Manchester, UK) four sector instrument of EBEB... 

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. 

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. 

FIBLAS experimental set up based on a 150 keV Sames accelerator and tandem magnetic mass analysis, eventually followed by electrostatic photofragment energy analysis. 

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