Surface enhancement of molecular ion H2+ yield in a 2.45-GHz electron-cyclotron resonance ion source
Xu Yuan1, Peng Shi-Xiang1, †, Ren Hai-Tao1, Zhang Ai-Lin1, 2, Zhang Tao1, Zhang Jing-Feng1, Wen Jia-Mei1, Wu Wen-Bin1, Guo Zhi-Yu1, Chen Jia-Er1, 2
       

(color online) current versus rf power for different materials.