[1] Chapman B E, Chiang C S, Prager S C, Sarff J S and Stoneking M R
1998 Phys. Rev. Lett. 80 2137

[2] Singh A K, Kaur R, Mattoo S K and Hirose A 2004 Phys. Plasmas
11 328

[3] Wan B N, Song M, Ling B L, Xu G S, Zhao Y P, Luo J R and HT-7 Team
2000 Nucl. Fusion 41 1835

[4] Tynan G R, Holland C, Yu J H, James A, Nishijima D, Shimada M and
Taheri N 2006 Plasma Phys. Control. Fusion 48 S51

[5] Wang G D, Wang L, Yang X Z, Feng C H, Jiang D M and Qi X Z 1998
Plasma Phys. Control. Fusion 40 429

[6] Wang W H, He Y X, Gao Z, Zeng L, Zhang G P, Xie L F, Yang X Z, Feng
C H, Wang L, Xiao Q and Li X Y 2005 Plasma Phys. Control. Fusion
47 1

[7] Ding B J, Kuang G L, Shan J F, Song M, Xu G S, Wan B N and Zhao Y P
2004 Phys. Plasmas 11 207

[8] Hidalgo C, Balin R, Pedrosa A, Garcia Cortes I and Ochando M A 1992
Phys. Rev. Lett. 69 1205

[9] Kumar R and Saha S K 2000 J. Phys. 55 731

[10] Rempel T D, Spragins C W, Prager S C, Assadi S, Den Hartog D J and
Hokin S 1991 Phys. Rev. Lett. 67 1438

[11] Yan L W, Hong W H, Qian J, Luo C W and Pan L 2005 Rev. Sci.
Instrum. 76 093506

[12] Stangeby P C, McCracken G M 1990 Nucl. Fusion 30 1225

[13] Martines E, Antoni V, Desideri D, Serianni G and Tramontin L 1999
Nucl. Fusion 39 581

[14] Zhao K J,Lan T,Dong J Q, Yan L W, Hong W Y, Yu C X, Liu A D, Qian
J, Cheng J, Yu D L, Yang Q W, Ding X T, Liu Y and Pan C H 2006 Phys.
Rev. Lett. 96 255004

[15] Yan L W, Hong W Y, Zhao K J, Dong J Q, Cheng J, Qian J, Yu D L,
Luo C W, Xu Z Y, Yang Q W and Ding X T 2006 Rev. Sci. Instrum.
77 113501

[16] Xu G S, Wan B N, Song M and Li J 2003 Phys. Rev. Lett.
91 125001

[17] Ido T, Miura Y, Hoshion K, Kamiya K, Hamada Y, Nishizawa A,
Kawasumi Y, Ogawa H, Nagashima Y, Shinohara K, Kusama Y and JFT-2M
Colabration 2006 Nucl. Fusion 46 512

[18] Xu Y H, Wang G D, Zhai K Wang C, Liu W D and Yu C Y 1996 Phys.
Plasmas 3 1022