Studies of Nonneutral Plasmas Confined on Helical Magnetic Surfaces of Heliotron J

摘要

Nonneutral plasmas confined on helical magnetic surfaces becomes have different characteristics from those of neutral plasmas. The most significant one observed in experiments is that both space potential bsand plasma density ne are not constant on closed magnetic surfaces. This strongly implies that such plasma parameters vary also along each magnetic field line (B-field line) with which closed magnetic surfaces are formed. In this paper, we have numerically estimated the variations of ф_s and n_e along helical B-field lines of the Heliotron J machine. Data show that on the magnetic axis, variatios of ф_sand ne are about 7 V and 2 x 10~7 m~(-3) for the case of B ~ 0.3 kG. Other accessible B-field lines and the estimated variations of ф_s and n_e on them are also presented