描述了简单磁镜装置MM-2中ECRH等离子体的H_α面发光度的特性,与朗缪尔探针、X射线探测器、反磁探针等测量结果相结合,给出了MM-2装置中ECRH等离子体的H_α发射时间特性及预电离特性等重要参数。结果表明,在热电子环建立之前,预电离期间已有H_α谱的发射,而在热电子环破裂之后,冷等离子体的衰减时间常数比热电子环的衰减时间常数大,这与X射线方法测量的结果是一致的。 The characteristic of H_α surface luminosity of ECRH plasma in MM-2 was described. Combined with the measurement results of Langmuir probe, X-ray detector and anti-magnetic probe, the MM-2 device In the ECRH plasma H_α emission time characteristics and pre-ionization characteristics and other important parameters. The results show that there is emission of H_α spectrum during the preionization before the thermionic ring is established, and the decay time constant of the cold plasma is larger than the decay time constant of the thermionic ring after the thermionic ring ruptures, which is in agreement with the X-ray method The measurement results are consistent.