Utilization of Beams of Charged Particles in Scientific Research and Industry

Abstract

A detailed discussion has been described about theory to cover different aspects of Auger spectroscopy . physical principles of Auger process , secondary electron spectrum and its application to surface studies . A beam of low energy electrons of 3000 eV is used to hit a coper target (coated with a thin layer of Nickel ) at a glancing angle O in order to produce Auger electrons . The primary beam (400 A of about 4 mm diameter) bombarded the surface under investigation The energy distribution of the secondary electrons was obtained by means of a four concentric semi-spherical grid arrangement and a collector . This arrangement used as a retarding field analyser RFA, organizes Auger electrons according to there energies in a spectrum. The retarding voltage , applied to the second and third grids . prevents electrons having an energy less than that corresponding to the retarding voltage from passing the grid system A small voltage applied to the collector increases the energy of the electrons striking it so that stable collection is possible through adequate bombardment . The collected current obtained is recorded versus the retarding voltage An operator named " ZAST " is used to calculate the second derivative of the collected current. A computer program has been prepared to interpolate the experimental data , calculate the second derivative and