1. Measurement of magnetic island width by using multi-channel ECE radiometer on HT-7 tokamak Han Xiang( 韩翔 ), Ling Bili( 凌必利 ), Gao Xiang( 高翔 ), Liu Yong( 刘永 ), Ti Ang ( 提昂 ), Wang Yumin( 王嵎民 ) July 19 2011 1/18

2. Outline Method to evaluate the magnetic island width by ECE specifications of HT-7 tokamak and multi-channel ECE heterodyne radiometer Measurement of magnetic island of electron temperature on HT-7 Summary of this work 2/18

3. Method to evaluate the magnetic island width by ECE specifications of HT-7 tokamak and multi-channel ECE heterodyne radiometer Measurement of magnetic island from ECE on HT-7 Summary of this work 3/18

4. Introduction The magnetic island can degrade the plasma confinement or even lead to a disruption Such kind of destabilization is thought to be caused by the local loss of bootstrap current It’s key issues that the magnetic island suppression for experimental tokamak or commercial reactors such as ITER Electron cyclotron emission (ECE) as an primary diagnostic could be applied for magnetic island research 4/18

5. A. Isayama et al. plasma phys. Control fusion 41 (1999) 35-43 ECE measurement on JT-60U Te profile for island width and its evolution ECE oscillation contour for island width, rotation frequency, the inverted phase and so on Inverted phase at R=3.65m 5/18

6. Nagayama et al. Phys. Plasmas 3, 7, 1996 ECE measurement on TFTR 6/18

7. Nagayama et al. Phys. Plasmas 3, 7, 1996 Different island result on TFTR 7/18

8. Method to evaluate the magnetic island width by ECE specifications of HT-7 tokamak and multi-channel ECE heterodyne radiometer Measurement of magnetic island from ECE on HT-7 Summary of this work 8/18

9. Major radius: R=1.22m Minor radius: a=0.27m Limiter: Mo & liquid Li Heating: Lower hybrid wave and ICRF HT-7 tokamak 9/18

10. Horizontal distribution along middle plane Spatial resolution: 2cm 2 nd harmonic frequency: 98.5~126GHz Channel location with frequency ： Multi-channel ECE on HT-7 tokamak Heterodyne radiometer ECE diagnostic 10/18

11. Method to evaluate the magnetic island width by ECE specifications of HT-7 tokamak and multi-channel ECE heterodyne radiometer Measurement of magnetic island from ECE on HT-7 Summary of this work 11/18

12. ECE oscillation phase inverse Mirnov coils oscillation signals for shot 112810 12/18

13. ECE oscillation analysis for shot112810 frequency( GHz) ECE01 98.501 ECE021 00.433 ECE031 02.366 ECE04 104.299 ECE05 106.232 ECE06 108.165 ECE08 112.031 ECE10 114 Location (m)1.21711.19371.17111.14941.12851.10831.07011.0516 oscillation phase inverse oscillation frequency: 3.5kHz amplitude ~ 10% 13/18

14. poloidal ： 12 coils, fixed among 30° measuring the poloidal mode toroidal ： 9 coils, asymmetrical measuring the toroidal mode Mirnov coils signals for Shot112810 m=2 n=1 14/18

15. time: 515.066 0.02mstime: 536.617 0.02ms Two moments analysis for Shot112810 15/18

16. Method to evaluate the magnetic island width by ECE specifications of HT-7 tokamak and multi-channel ECE heterodyne radiometer Measurement of magnetic island from ECE on HT-7 Summary of this work 16/18

17. The magnetic island width of m/n=2/1 mode is evaluated using ECE diagnostic on HT-7 Saturated island width of 2/1 mode is about 5cm, ; island rotation frequency is 3.5kHz. The island information can be obtained by ECE diagnostic. This method is useful for the research of NTM on EAST experiment in the future. 17/18

18. Thank you ！ 18/18