中文摘要：

利用数值积分方法求解色散方程,研究托卡马克等离子体中杂质模的不稳定效应,分别模拟了不同杂质离子所激发的杂质模在不同参数下的变化情况.结果表明,杂质模驱动的等离子体不稳定性通常随杂质离子的质量和电荷数增大而增大,但也有反常的情况,质量很大的杂质离子可能导致更小的不稳定性.杂质模的激发必须使杂质离子浓度超过一定的阈值,杂质离子越轻,电荷数越低,阈值越大.更强或更弱的磁剪切效应都有利于抑制杂质模的不稳定性.在k（θρs）谱图中,钨（W^＋8）杂质模有更小的谱宽度.

英文摘要：

The instability effect driven by impurity mode is studied using a numerical method of integral dispersion equation in toroidal configuration. Impurity modes excited by various impurity ions are investigated under different parameters conditions.It is found that the greater instability is related to the heavier impurity ion mass and higher charge numbers,but there is an abnormal fact that heavier impurity ions lead to a bigger destabilizing effect on the mode.In addition,the excitation of impurity mode has to exceed the impuritycharge concentration threshold,and the impurity ions with lighter mass and lower charge number produce a smaller threshold. The destabilizing effect of impurity mode is gradually suppressed in the stronger and weaker magnetic shear region.The impurity mode with W~（＋8） ion has the narrowest of the spectra width.