Abstract

A novel approach was given by both beam simulation (using SIMION computer program) and analytical treatment, which are useful tools for the design of a constant gradient acceleration system. An analytical treatment is used to simulate the beam line within a single gap accelerating system. The tracing of the beam line inside the gap shows a decrease of the beam output radius with the increase of the accelerating voltage ratio applied to the gap up to an optimal value. Beyond this optimal value, the beam line aberration appears in the form of cross over. A series of simulation studies were made in order to determine optimum conditions for acceleration of space-charge-dominated argon gas with different incident energies at constant gradient acceleration system. Beam simulation is carried out to reveal both the influence of the space charge effect and incident beam energy on the beam emittance and beam radius. The influence of voltage ratio and inner accelerating tube diameter has the same influence on the output beam emittance.From the beam simulation, the appropriate voltage ratio is 3 and inner accelerating tube diameter is 15 mm. Both analytical and simulation studies have a good agreement results.

Key words: SIMION computer program, DC acceleration system, beams emittance.