TY - JOUR
T1 - Analysis of plasma equilibrium based on orbit-driven current density profile in steady-state plasma on QUEST
AU - Nakamura, K.
AU - Alam, M. M.
AU - Jiang, Y. Z.
AU - Mitarai, O.
AU - Kurihara, K.
AU - Kawamata, Y.
AU - Sueoka, M.
AU - Takechi, M.
AU - Hasegawa, M.
AU - Tokunaga, K.
AU - Araki, K.
AU - Zushi, H.
AU - Hanada, K.
AU - Fujisawa, A.
AU - Idei, H.
AU - Nagashima, Y.
AU - Kawasaki, S.
AU - Nakashima, H.
AU - Higashijima, A.
AU - Nagata, T.
AU - Fukuyama, A.
N1 - Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2016
Y1 - 2016
N2 - In the present RF-driven (ECCD) steady-state plasma on QUEST (Bt = 0.25 T, R = 0.68 m, a = 0.40 m), plasma current seems to flow in the open magnetic surface outside of the closed magnetic surface in the low-field region according to plasma current fitting (PCF) method. We consider that the current in the open magnetic surface is due to orbit-driven current by high-energy particles in RF-driven plasma. So based on the analysis of current density profile based on the orbit-driven current, plasma equilibrium is to be calculated. We calculated high energy particles guiding center orbits as a contour plot of conserved variable in Hamiltonian formulation and considered particles initial position with different levels of energy and pitch angles that satisfy resonance condition. Then the profile of orbit-driven current is estimated by multiplying the particle density on the resonance surface and the velocity on the orbits. This analysis shows negative current near the magnetic axis and hollow current profile is expected even if pressure driven current is considered. Considering the hollow current profile shifted toward the low-field region, the equilibrium is fitted by J-EFIT coded by MATLAB.
AB - In the present RF-driven (ECCD) steady-state plasma on QUEST (Bt = 0.25 T, R = 0.68 m, a = 0.40 m), plasma current seems to flow in the open magnetic surface outside of the closed magnetic surface in the low-field region according to plasma current fitting (PCF) method. We consider that the current in the open magnetic surface is due to orbit-driven current by high-energy particles in RF-driven plasma. So based on the analysis of current density profile based on the orbit-driven current, plasma equilibrium is to be calculated. We calculated high energy particles guiding center orbits as a contour plot of conserved variable in Hamiltonian formulation and considered particles initial position with different levels of energy and pitch angles that satisfy resonance condition. Then the profile of orbit-driven current is estimated by multiplying the particle density on the resonance surface and the velocity on the orbits. This analysis shows negative current near the magnetic axis and hollow current profile is expected even if pressure driven current is considered. Considering the hollow current profile shifted toward the low-field region, the equilibrium is fitted by J-EFIT coded by MATLAB.
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U2 - 10.1016/j.fusengdes.2015.11.035
DO - 10.1016/j.fusengdes.2015.11.035
M3 - Article
AN - SCOPUS:84950291667
SN - 0920-3796
VL - 109-111
SP - 1528
EP - 1533
JO - Fusion Engineering and Design
JF - Fusion Engineering and Design
ER -