Analysis of H- extraction in the Linac4 negative ion source by 2.5D particle simulation

The purpose of this study is to investigate the extraction mechanisms of the H− ions in the Linac4 negative ion source by using an improved two-dimensional in real space and three-dimensional in velocity space Particle in Cell (2D3V-PIC) model. In this model, the following collision processes of the surface produced H− (Hsp−) ions have been introduced and the effects of the collisions on H− extraction have been analyzed: elastic (Hsp− - H2) and charge exchange (Hsp− - H). It is shown that the extracted Hsp− current increases due to the flow reversal of the Hsp ions caused by these collisions.The purpose of this study is to investigate the extraction mechanisms of the H− ions in the Linac4 negative ion source by using an improved two-dimensional in real space and three-dimensional in velocity space Particle in Cell (2D3V-PIC) model. In this model, the following collision processes of the surface produced H− (Hsp−) ions have been introduced and the effects of the collisions on H− extraction have been analyzed: elastic (Hsp− - H2) and charge exchange (Hsp− - H). It is shown that the extracted Hsp− current increases due to the flow reversal of the Hsp ions caused by these collisions.