Speaker
Jie Wu
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P1.1082.pdf
Inward Transport Induced by the Long Lived Mode in HL-2A H-
mode plasma
J. Wu1, T. Lan1, J. R.Wu1, M. Xu2, L. Nie2, W. Chen2, L. M. Yu2, J. Cheng2, L. W. Yan2,
X. R. Duan2, Y. Liu2, T. J. Deng1, H. Q. Xu1, S. Zhang1, Y. Yu1, X. Sun1, A. D. Liu1, J.
L. Xie1, H. Li1, G. Zhuang1, W. D. Liu1
1
KTX Laboratory and Department of Modern Physics, University of Science and Technology
of China, Hefei 230026, P.R. China
2
Southwestern Institute of Physics, Chengdu 610041, P.R. China
In the past two decades, the fluctuation induced inward flux was mainly studied in
stellarators[1, 2] and less in tokamak[3, 4]. From the frequency resolved expression of
fluctuation induced flux, the cross phase between electric field fluctuation E and pressure
fluctuation ne is the main term that changes the direction of turbulence transport flux[5] which
is different from the zonal flow to suppress turbulence by reducing the amplitude of fluctuation
level[6]. In HL-2A tokamak plasmas, the inward flux induced by the Long Lived Mode (LLM)
has been firstly observed in spontaneous L-H transition by using Langmuir probe array. The
LLM is a kind of energetic particle modes (EPMs) excited by the resonance between internal
kink mode and precessional motion of energetic trapped ions [7] or excited by energetic
electron[8] in core region of HL-2A. In the edge region with strong E B shear, the radial
flux induced by LLM is reversed to inward because the cross phase term cos E n becomes e
negative. By using the long-range correlation in radial direction between Langmuir probe and
core soft X-ray signal, we find the poloidal electric field fluctuation E phase reversal is the
main cause that leading to the inward transport. The other probe settled in the poloidal distance
of 80 mm also observers the same inward flux phenomenon, which indicates the inward flux
has a global characteristic. Furthermore, the inward flux may help to build the transport barrier
and improve the confinement of turbulence transport.
References
[1] M. Shats. et al Phys. Rev. Let. 79 (1997) 2690.
[2] K. Toi. et al Plasma Phys. Control. Fusion 44 (2002) A237.
[3] J. Boedo. et al Nucl. Fusion 40 (2000) 1397. Y.Xu. et al Phys. Rev. Lett. 97 (2006) 165003.
[4] D. Kong. et al Nuclear Fusion 58 (2018) 034003.
[5] P.W. Terry. et al Phys. Rev. Let. 87 (2001).
[6] H.G. Shen. et al Phys. Plasmas 23 (2016) 042305.
[7] R.B. Zhang. et al Plasma. Phys. Control. Fusion. 56 (2014) 095007.
[8] L.M. Yu. et al Nucl. Fusion 57 (2017).
