Speaker
Mr
Yi Tan
(Tsinghua University)
Description
The coupling between Alfven waves and plasmas are studied before applying high power rf waves to drive current in the SUNIST spherical tokamak (R/a: 0.3 m/0.23 m; B_T0: 0.15 T; I_P: 30~70 kA; n_e: ~1E19 m^-3; pulse length: 10~25 ms). The impedance of antennas reflects the coupling and can be easily obtained from the rf voltage across and the rf current through the antennas since the frequencies of the waves are low. The evolution of wave coupling in typical discharges confirms that the coupling heavily depends on the electron density and the plasma shape. The impedance of the antennas without BN limiters as a function of frequency qualitatively agrees with the 1-d MHD calculation results of mixed N=1/-1 and M=1/-1 modes. However, the dependence of the impedance of antennas with BN limiters on toroidal field is much weaker. The Alfven continuum is obtained by continuously scanning the toroidal field.
| Country or International Organisation | China |
|---|---|
| Paper Number | EX/P6-56 |
Primary author
Mr
Yi Tan
(Tsinghua University)
Co-authors
Mr
Yangqing Liu
(Department of Engineering Physics, Tsinghua University)
Prof.
Zhe Gao
(Tsinghua University)
