Numerical study on variable aperture extraction grids of a titanium hydride cathodic vacuum arc ion source

Abstract

Titanium hydride cathodic vacuum arc ion sources are widely used in particle accelerators, neutron sources, etc. For the application in neutron sources, higher H+/D+ fraction and higher beam uniformity are preferred. In this work, to improve the beam uniformity of a miniature titanium hydride cathodic vacuum arc ion source, a new scheme of variable aperture extraction grids is proposed. A 2D numerical model is developed for the investigation of the variable aperture extraction grids. Numerical results indicate that the extraction grid plays important roles in the titanium hydride cathodic vacuum arc ion source that can improve the stability of ion source. Moreover, simulated results show that the designed variable aperture extraction grids can reduce the beam nonuniformity to less than ±10%, while the beam nonuniformity of the fixed aperture extraction grids are between ±22% and ±37%. Thus, the presented work can provide a potential reference for the improvement of beam uniformity of the vacuum arc ion sources.