The interaction of plasma with a material surface in the presence of a strong magnetic field is a subject of high interest in tokamak plasmas. For example, the ITER divertor is castellated with tiles to withstand strong thermomechanical stresses. Plasma will flow to the surface of the tiles, thus will cause the retention of deuterium and tritium in the tiles. A better understanding about transport of plasma in the sheath near the tiles is benefit to solve the problem.

In this paper, we simulate the characteristics of sheath in strong magnetic field using a fluid model. In the model we consider two species of positive ions (D⁺ and T⁺ ), the influence of the magnetic field strengths and orientations on the plasma sheath is discussed. We also pay our attention to the effect of divertor biasing on the velocity and density distribution of both ion species in the sheath.

This work was jointly supported by the National Basic Research Program of China (No.2009GB106002) and Science Research Foundation of Dalian University of Technology.

References

[1] X. Zou, M. Qiu, H. Liu, L. Zhang, J. Liu, Y. Gong, Vacuum 83 (2009) 205

[2] S. F. Masoudi, S.S. Esmaeili, S. Jazavandi, Vacuum 84 (2010) 382