1. Proc. 11th Symp. on Ion Source and Ion Assisted Technology;Ohmatsu,1987
2. Proc. 13th Symp. on Ion Source and Ion Assisted Technology;Ogasawara,1990
3. Proc. IAEA Tech. Committee Meet. on Negative Ion Based Neutral Beam Injectors;Ogasawara,1991
4. Proc. Workshop on Negative Ion Formation and Beam Handling;Ogasawara,1994
5. Sixth Int. Symp. on the Production and Neutralization of Negative Ions and Beams;Ando,1994