Investigation and application of hollow anode glow discharge ion source

Abstract

In the present work, a new shape of a glow discharge ion source has been designed, fabricated and constructed at Accelerators and Ion Sources Department, Nuclear Research Center, Egyptian Atomic Energy Authority, Egypt. The discharge and output beam characteristics of the ion source at different operating gas pressures have been measured at the optimum distance between the anode and the cathode (3.5 mm) using hydrogen and nitrogen gases. Furthermore, mixture of different gases was studied, e.g., addition of H 2 gas to N 2 gas with different ratios has been investigated. Finally, as an application of this new ion source, ion beam modification of insulators (glass) which depends on glass structure has been achieved. It has been found that, the transmission of light is decreased by coating the glass surface with Ar ion beam more than coating with plasma of Ar gas at the same pressure and the same exposure time. So we could use this ion source as a coating tool for borate glass surface. The parameters affected the glow discharge ion source efficiency have been examined carefully using a mixture of gases. Using helium gas, the glow discharge is in a turbulent state due to instabilities. An investigated H 2–N 2 mixture has been used in order to obtain an optimum percentage of the mixture of the two gases to increase the electric field necessary for ionization balance.