Experimental Results of IBW heating on the HT-7

1. HT-7 ASIPP Experimental Results of IBW heating on the HT-7 Chengming Qin, Yanping Zhao, Weici Shen, Haiqian Liu, Bo lv, Guosheng Xu, HT-7team Institute of Plasma Physics, Chinese Academy of Science, Hefei, China

2. HT-7 Abstract An Ion Bernstein wave heating experiments using different frequency (27MHz and 30MHz) was carried out on HT-7 in the recent IBW experiment. At 30MHz, ne peaked and Hа dropped have been pervasive observed, P was improvedfactor of 2-3. Energy confinement was improved by factor of 1-1.5. Obviously confinement of particle was observed during the IBW pulse.At 27MHz, by choosing layer location, the globe and localized heating phenomena can be observed, Central electron heating effect was obtained in the global heating mode and electron temperature strongly increased near the 2ΩD resonant layer for localized heating .

3. HT-7 content • ICRF system • IBW system • At 30MHz IBW heating experiment • At 27MHz IBW heating experiment • Summary

4. ICRF Heating System in HT-7 Tokamak

5. HT-7 IBW System Frequency:0~30MHz RF Power: 0~350kW RF Pulse length:CW Matching System: Two Stub-tuners T-type Antenna: Area:(490+150)cm2 n||: Peaked at 8 for 27 MHz Central conductor: TiN coating Shielding and side protector:graphite

6. HT-7 IBW heating with 30MHz PRF~160kW, Bt=1.95T,Ip=150kA Significant improvement of particle confinement was observed Before IBW powerτp~5ms,after injection IBW, τp~15ms,increased by factor of 2-3

7. HT-7 IBW heating with 27MHz global heating:. BT=1.9T, rH ~ 3.9cm The electron temperature Te in the location r= 3cm > Te in the location r= 12cm in IBW heating phase,the maximum electron temperature reached to about 2.4kev .Central electron heating effect was observed.

8. HT-7 27MHz IBW heating Localized heating :BT=2.0T, rH ~ 10cm Ha andτp almost unchanged. No particle confinement observed The electron temperature Te in the location r= 12cm > Te in the location r= 9cm in IBW heated phase

9. HT-7 27MHz IBW heating • Ne increased and peaked • Te globally increased only around the H layer • Localized heating was obtained

10. HT-7 Summary In this IBW experiment , we mainly obtained these experimental results: • For30 MHz, Particle confinement obvious improvement and strongly increased and very peaked density profile were observed. • For 27 MHz, both global and localized electron heating’ phenomena were observed by changing the location of the 2 ΩD resonant layer.(a) Central electron heating effect was obtained in the global heating mode on the HT-7 Tokamak.(b)Electron temperature strongly increased near the 2ΩD resonant layer for localized heating was observed. There is no obviously improvement of particle confinement in the localized heating modes.

11. HT-7 reference 1.Ono, M., Phys. Fluids B 2 (1993) 241 2.Biglari H., Diamond P.H. and Terry P.W. 1990 Phys. Fluids B 2 1 3.L. A. Berry, E. F. Jaeger, and D. B. Batchelor, Phys. Rev. Lett. 82, 1871 4. B. LeBlanc, R. E. Bell, S. Bernabei et al., Phys. Rev. Lett. 82, 331 ~1999!. 5. Zhao,Y, et al., 19thIAEA Fusion Energy Conference, IAEA-CN-77/EXP4/30, 14–19 Octo-ber 2002, Lyon, France ~International Atomic Energy Agency, Vienna, 2003). 6. Baonian Wan, et al., Physics of Plasma 9(2003) 3703-3711