242—260nm波长区CS_2分子的多光子解离电离

The Multiphoton Dissociation and ionization of CS_2 in the Range 242-260nm

在242－260nm波氏范围通过CS2分子的共振增强多光子电离（REMPI）获得了母体离子CS和碎片离子的分质量激发谱．在λ＜246.4nm区间，CS激发谱上呈现出来源于CS2双光子电离的弥散谱带,碎片离子激发谱的归属强烈提示多光子过程中有中性基电子态的CS和S（经由CS2的光解离）产生：（1）CS+的谱带主要来源于中性CS碎片经由单光子跃迁产生的（1＋1）共振增强电离，（2）除了部分S+的谱峰来自CS+的光解外，多数S+的锐谱峰来自中性S原子经由3p3（2D0）4p，3p3（4S0）np（n＝6，7，8）←3p43pJ（J＝2，1,0）双光子跃迁产生的（2＋1）共振增强电离．

The mass-selected excitation spectra for parent ion CS and the fragmentatiou ions CS+, S+ and C+ are obtained by using the resonance-enhanced multiphoton ionization (REMPI)of CS2 in the range 242 260nm. It is shown that the diffuse bands of CS in range of λ<246.4nm are mainly from the two-photon ionization of CS2. It has been reasonably assumed from the assignments of excitation spectra for the fragments that the neutral CS and S are produced by the photodissociation of CS2 in the process, that is, (1) the bands of CS+ are mainly due to the (1+1) resonance-enhanced ionization via the one-photon transition of the fragluent CS, (2) besides part of S+ spectral peaks are from the dissociation of CS+, Inost of S+spectral peaks are due to the (2+1) resonance-enhanced ionizatinn via the. two-photon transition 3p3 (2D0) 4p. 3p3 (4S0) np (n=6,7,8)←3p4 3PJ (J=2,1,0) of S atoms.