| Autor: |
Ma, J.F., Xu, X.Q., Dudson, B.D. |
| Předmět: |
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| Zdroj: |
Nuclear Fusion; Mar2014, Vol. 54 Issue 3, p033011-033019, 9p |
| Abstrakt: |
We present linear characteristics of peeling–ballooning (P–B) modes in the pedestal region of DIII-D tokamak with snowflake (SF) plus divertor configuration using edge two-fluid code BOUT++. A set of reduced magnetohydrodynamics (MHD) equations is found to simulate the linear P–B mode in both snowflake plus and standard (STD) single-null divertor configurations. Further analysis shows that the implementation of snowflake geometry changes the local magnetic shear in the pedestal region, which leads to different linear behaviours of the P–B mode in STD and SF divertor configuration. Primary linear simulation results are the following. (1) The growth rate of the coupled P–B mode in SF-plus divertor geometry is larger than that in STD divertor geometry. (2) The global linear mode structures are more radially extended yet less poloidally extended in SF-plus divertor geometry, especially for moderate and high toroidal mode numbers. (3) The current-gradient drive (the kink term) dominates the P–B mode for low n, while the pressure gradient drive (ballooning) dominates for n > 25. In addition, constraints on poloidal field and central solenoid coils for snowflake geometry are briefly discussed based on conclusions in this paper. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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