الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
The present thesis deals with a detailed study of the theory, design, construction, and operation of high-current electron gun which will be utilized in a8-MeV electron linear accelerator. The theory of electron gun wit its optical system were reviewed and accordingly a design of a 80 KV-electron gun was carried out to guarantee the production of a well – focused convergent conical beam with certain specifications needed for the electron linear accelerator. The electron gun which was designed using piece’s method has a high degree of efficiency.
Spangenberg method has been adapted for the determination of gun – electrode shapes which in turns were approximated to be linear geometry instead of curvilinear one. It was found that the electrode shapes approximation have a significant effect in the electron gun geometry design parameters.
The study o the space-charge force on the electron beam convergence shows that it has a negligible effect in the cathode-anode region, while it has a considerable effect in the free field drift-space region of the designed electron gun.
Detailed experimental investigations of the gun characteristics were carried out. The effects of the filament power, accelerating voltage and frequency on the gun characteristics were studied. Also, the output beam current and gun current losses were investigated, using specially designed cooled faraday cup for measurements.
The beam profile was also studied using a specially designed measuring probe jig for current measurements in both axial and radial directions.