轴向磁场中辐射对电弧的螺旋不稳定性的影响

THE EFFECT OF RADIATION TO THE HELICAL INSTABILITY OF ARCS IN AN AXIAL MAGNETIC FIELD

采用抛物型电导率、抛物型透明辐射和与时间有关的线性微扰理论，给出了中、小电流弧的热势分布（温度分布）、稳定性条件以及不稳定性增长率等定量结果．得出辐射对中。

The helical instability of an arc column with electrical conductivity of the parabolic distribution and transparent radiation of the parabolic distribution is discussed in axial magnetic field.The magnetohydrodynamic equations serve as the strarting point of the theory.In an electrostatic approximation and a linear time dependent perturbation theory,the perturbation equations for the arc column movement are deduced.Solutions of these equations are obtained analytically,from which the stability limit of the cylindrical arc and the growth rate of the helical instability are given.In comparision the results with those of current distribution without radiation,it is found that the radiation in the small middle arc increases the instability.