中文摘要：

介绍了针对中国联合球形托卡马克氦放电等离子体建立的碰撞辐射（CR）模型.给出CR模型计算的来自主量子数n =4激发态能级的三条谱线的强度比447.1 nm （23P-43S）/492.2 nm （21P-41D）和492.2 nm/504.8 nm （21 P-41 S）在电子温度Te和电子密度Ne空间内的计算结果.建立了根据谱线强度比确定Te与Ne的谱线比法.将该方法应用在氦放电等离子体诊断上，通过与微波干涉仪测量结果的对比以及CR模型与实验测量的激发态数密度的对比验证了方法的有效性.分析了引起诊断结果误差的因素，包括实验测量设备误差、CR模型使用的速率系数不确定度与能级选取，以及光谱测量的弦积分特性等.

英文摘要：

The collisional-radiative model, that has been constructed for the helium plasma in the Sino-United Spherical Tokamak is introduced. The result of the 447.1 nm （23P-43S）/492.2 nm （21P-41D） and 492.2 nm/504.8 nm （21P-41S） line ratios is given. The line ratio method that is used for measuring electron temperature Te and density Ne parameters is described. The result from the line ratio method is consistent with the measurement of the 94 GHz interferometer. The method is also validated by comparing the relative population densities of the excited states which are deduced from the CR model and the measured intensity data of helium lines. The factors that brings errors into the diagnostic result are discussed, including the error from the measurements, and those from the uncertainties of the rate coefficients that are used in the CR model and the viewing chord integration characteristic of the optical emission measurement.