Practical 2.45-GHz microwave-driven Cs-free H<sup>−</sup> ion source developed at Peking University<xref rid="cpb_27_10_105208_fn1" ref-type="fn">*</xref><fn id="cpb_27_10_105208_fn1"> <label>*</label> <p>Project supported by the National Natural Science Foundation of China (Grant Nos. 11775007 and 11575013).</p></fn>

Practical 2.45-GHz microwave-driven Cs-free H⁻ ion source developed at Peking University* *

Project supported by the National Natural Science Foundation of China (Grant Nos. 11775007 and 11575013).

Zhang Tao, Peng Shi-Xiang^†, Wu Wen-Bin, Ren Hai-Tao, Zhang Jing-Feng, Wen Jia-Mei, Ma Teng-Hao, Jiang Yao-Xiang, Sun Jiang, Guo Zhi-Yu, Chen Jia-Er

(color online) The transversal magnetic field at axis of Φ50 mm H⁻ ion source (0 mm position represents the outer edge of the plasma electrode extraction hole which is labeled in Fig. 1, and the arrow of the axis in Fig. 1 points in the positive direction.)