Electrostatic particle accelerator

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. 

Figure 5 Components (not to scale) of a typical nuclear microprobe system (A) electrostatic particle accelerator (B) primary object aperture (C) secondary collimator (D) focusing system (E) scanning system (F) video camera and microscope (G) surface barrier detector for scattered particles (H) X-ray detector (I) specimen (J) surface barrier detector for transmitted particles (STIM) (K) front-end CAMAC with data bus (L) main computer and display with elemental map. (Reprinted with permission from Maenhaut W and Malmqvist KG (2001) Particle-induced X-ray emission analysis. In Van Grieken RE and Markowicz AA (eds.) Handbook of X-Ray Spectrometry, 2nd edn. Ch. 12, pp. 719-809. New York Dekker Marcel Dekker Inc.)...

The characterization and control of electrostatic forces are of particular interest. Electrostatic forces depend on the electric charge and potential at the particle surfaces. When subjected to a uniform, unidirectional electric field E. charged colloidal particles accelerate until the electric body force balances the hydrodynamic drag force, so that the particles move at a constant average velocity v. This motion is known as electrophoresis, and v is the electrophoretic velocity. 

M. S. Livingstone, J. P. Blewett, Particle Accelerators, McGraw-Hill, New York, 1962 M. H. Blewett, The Electrostatic (Van de Graafi) Generator, in Methods of Experimental Physics (Eds. L. C. L. Yuan, C. S. Wu), Vol. 5B, Academic Press, New York, 1963 P. M. Lapostolle, L. Septier, Linear Accelerators, North-Holland, Amsterdam, 1970 A. P. Wolf, W. B. Jones, Cyclotrons for Biomedical Radioisotope Production, Radiochim. Acta 34, 1 (1983)... 

Figure 1 Schematic depictions of electrostatic (a) and oscillating electromagnetic (b) fields for charged particle acceleration.

Application of an electric field to an ion in solution causes the ion to move with a constant velocity that depends on the field strength, temperature and characteristic properties of the ion and electrolyte solution. The electrostatic force accelerating the ion (F = qE) is opposed by viscous forces in the solution restricting its movement. For a spherical particle the viscous force is given by Stokes law (F = firttirvep). After a short... 

Can an electrostatic or magnetic fieid be used to accelerate neutrons in a particle accelerator Why or why not ... 

NUCLEAR TRANSMUTATIONS (SECTION 21.3) Nuclear transmutations, induced conversions of one nucleus into another, can be brought about by bombarding nuclei with either charged particles or neutrons. Particle accelerators increase the kinetic energies of positively charged particles, allowing these particles to overcome their electrostatic repulsion by the nucleus. Nuclear transmutations are used to produce the transuranium elements, those elements with atomic numbers greater than that of uranium. 

SuUer V, Petit-Jean-Genaz Ch (1994) In SuUer V, Petit-Jean-Genaz Ch (eds) Proceedings of the fourth European particle accelerator conference. World Scientific, Singapore/New Jersey/London/Hong Kong Takacs J (1997) Energy stabilization of electrostatic accelerators. Wiley, Chichester... 

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