Magnetic potential based formulation for linear and non-linear 3D RF sheath simulation

Nuclear Fushion

article

S. Shiraiwa¹  N. Bertelli¹  W. Tierens²  R. Bilato²  J. Hillairet³  J. Myra⁴  H. Kohno⁵  M. Poulos¹  M. Ono¹ 

[1] Princeton Plasma Physics Laboratory, Princeton;Max-Planck-Institut für Plasmaphysik;CEA;Lodestar Research Corporation;Kyushu Institute of Technology

关键词: ICRF;    full-wave simulation;    RF sheath;   

DOI  :  10.1088/1741-4326/aca6f9

来源: Institute of Physics Publishing Ltd.

【 摘 要 】

This paper reports a new numerical scheme to simulate the radio-frequency (RF) induced RF sheath, which is suitable for a large 3D simulation. In the RF sheath boundary model, the tangential component of the electric field (E_mathrm{t} ) is given by the gradient of a scalar electric field potential. We introduce two additional scalar potentials for the tangential components of the magnetic field, which effectively impose the normal electric displacement ( D _n ) on the plasma sheath boundary condition via in-homogeneous Neumann boundary condition and constrain the tangential electric field on the surface as curl-free (abla imes E_mathrm{t} = 0 ). In our approach, the non-linear sheath impedance is formulated as a natural extension of the large thickness (or asymptotic) sheath limit (D_mathrm{n} = 0 ), allowing for handling both asymptotic and non-linear regimes seamlessly. The new scheme is implemented using the Petra-M finite element method analysis framework and is verified with simulations in the literature. The significance of non-linearity is discussed in various plasma conditions. An application of this scheme to asymptotic RF sheath simulation on the WEST ICRF antenna side limiters is also discussed.

【 授权许可】

Unknown