Abstract
The dynamics of the core and outer micro-turbulence during the low–intermediate–high (L–I–H) confinement transition have been investigated simultaneously by a tangential CO2 laser collective scattering system on EAST. It is found that, the intensity of micro-turbulence decreases most strongly near the outer region of the plasma, with less dramatic reduction deeper into the plasma. During the transition, the cross-coherence between broadband turbulence at neighboring wave-numbers in the same region of the plasma increase from less than 0.3 to greater than 0.8 just after the I–H transition. Besides, the magnetic fluctuations in the LCO frequency range reaches a maximum just before the final transition to H-mode, indicating the plausible underlying role of the perturbation of the pressure gradient in the triggering of the transition dynamics. These results would help to achieve a more comprehensive understanding of the L–H transition mechanism.
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References
ITER Physics Basis Expert Groups on Confinement and Transport and Confinement Modelling and Database, ITER Phys. Basis Editor. Nucl. Fusion 39, 2175 (1999)
K.H. Burrell, Phys. Plasmas 4, 1499 (1997)
P.H. Diamond et al., Plasma Phys. Control. Fusion 47, R35 (2005)
K. Itoh et al., Phys. Plasmas 13, 055502 (2006)
G.R. Tynan et al., Plasma Phys. Control. Fusion 51, 113001 (2009)
S.-I. Itoh, K. Itoh, Phys. Rev. Lett. 60, 2276 (1988)
E.J. Kim, P.H. Diamond, Phys. Rev. Lett. 90, 185006 (2003)
G.D. Conway et al., Phys. Rev. Lett. 106, 065001 (2011)
T. Estrada et al., Phys. Rev. Lett. 107, 245004 (2011)
L. Schmitz et al., Phys. Rev. Lett. 108, 155002 (2012)
G.S. Xu et al., Nucl. Fusion 54, 103002 (2014)
T. Kobayashi et al., Phys. Rev. Lett. 111, 035002 (2013)
K.H. Burrell et al., Phys. Plasmas 1, 1536 (1994)
G. McKee et al., Plasma Fusion Res. 2, S1025 (2007)
H.Q. Wang et al., Nucl. Fusion 52, 123011 (2012)
G.M. Cao et al., Fusion Eng. Des. 89, 3016 (2014)
C. Liang et al., J. Fusion Energ. 33, 471–475 (2014)
E. Mazzucato, Plasma Phys. Control. Fusion 48, 1749 (2006)
E. Mazzucato, Phys. Plasmas 10, 753 (2003)
D.R. Smith et al., Rev. Sci. Instrum. 79, 123501 (2008)
Y.M. Duan et al., Plasma Sci. Technol. 13, 546 (2011)
G.S. Xu et al., Phys. Plasmas 19, 122502 (2012)
E.J. Doyle et al., Nucl. Fusion 47, S18 (2007)
R.D. Keane et al., Appl. Sci. Res. 49, 191–215 (1992)
Lonnie. Hudgins et al., Phys. Rev. Lett. 71, 3279 (1993)
G.M. Cao et al., Phys. Scr. 90, 025603 (2015)
G.M. Cao et al., Phys. Plasmas 22, 022505 (2015)
Acknowledgments
This work was supported by the National Nature Science Foundation of China with Contracts Nos. 11275232, 11475222. The authors gratefully acknowledge the contribution of the EAST staff.
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Cao, G.M., Li, Y.D., Li, Q. et al. The Dynamics of Core and Outer Micro-turbulence During the L–I–H Confinement Transition on the EAST Superconducting Tokamak. J Fusion Energ 34, 1445–1450 (2015). https://doi.org/10.1007/s10894-015-9949-9
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DOI: https://doi.org/10.1007/s10894-015-9949-9