中文摘要：

采用光腔衰荡光谱（cavity ringdown spectroscopy,CRDS）技术在19870～20250cm-1能量范围内研究了AsH2自由基A2A1（000）-X2B1（000）带的高灵敏高分辨吸收光谱.AsH2自由基由AsH3/Ar混合气脉冲直流放电产生.通过对Ka′≤5,N′≤10的777根谱线进行了转动标识和最小二乘拟合,获得了精确的激发态光谱常数和转动项值.其中转动项值和部分高阶光谱常数均为首次得到.通过分析发现部分Ka′≤4的转动能级和全部Ka′≤5的能级受到了扰动,扰动很可能来自于基态的高振动激发态.

英文摘要：

The absorption spectra of AsH2 radical were recorded in 19870―20250 cm-1 by cavity ringdown spectroscopy.The AsH2 radicals were produced by pulsed DC discharge of a gas mixture of AsH3 in argon.Based on the previous studies,the obtained spectra can be assigned as the vibronic transition：A2A1（000）-X2B1（000）.Rotational assignments and least square fittings for about 777 rotational lines with Ka ≤5 and N ≤10 were carried out,and the rotational term values and the molecular parameters were also determined with reasonably high precision. The per- turbations observed for the upper state were briefly analyzed and discussed.