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). |
(color online) The peak H− current of 8.5 mA (No. 2 signal represents the fed microwave intensity; No. 1 signal represents the voltage measured in the Faraday cup). |