在研究热核聚变的实验装置内,获得高温等离子体的主要困难之一是在纯氢等离子体中混进了各种杂质.其存在,增加了辐射能量损失,降低了等离子体温度.通常用有效电荷Zeff来表示杂质对氢等离子体的污染程度.它的定义如下:其中Nk为第k种离子的浓度,Z k为它的电荷.　为对所有种类离子 One of the major difficulties in obtaining high-temperature plasma in an experimental setup for studying thermonuclear fusion is the inclusion of various impurities in the pure hydrogen plasma, which increases the loss of radiant energy and reduces the plasma temperature, The effective charge, Zeff, represents the degree of impurity contamination of the hydrogen plasma, and is defined as follows: where Nk is the concentration of the kth ion and Zk is its charge. For all types of ions