Department of Chemistry, University of California, Davis, Davis, California 95616, USA.
J Chem Phys. 2011 Aug 21;135(7):071101. doi: 10.1063/1.3626867.
We demonstrate that the vacuum ultraviolet (VUV) photodissociation dynamics of N(2) and CO(2) can be studied using VUV photoionization with time-sliced velocity-mapped ion imaging (VUV-PI-VMI) detection. The VUV laser light is produced by resonant sum frequency mixing in Kr. N(2) is used to show that when the photon energy of the VUV laser is above the ionization energy of an allowed transition of one of the product atoms it can be detected and characterized as the wavelength is varied. In this case a β parameter = 0.57 for the N((2)D°) was measured after exciting N(2)(o(1)Π(u), v(') = 2, J(') = 2) ← N(2)(X(1)Σ(g) (+), v(") = 0, J(") = 1). Studies with CO(2) show that when there is no allowed transition, an autoionization resonance can be used for the detection of a product atom. In this case it is shown for the first time that the O((1)D) atom is produced with CO((1)Σ(+)) at 92.21 nm. These results indicate that the VUV laser photodissociation combined with the VUV-PI-VMI detection is a viable method for studying the one-photon photodissociation from the ground state of simple molecules in the extreme ultraviolet and VUV spectral regions.
我们证明，使用真空紫外（VUV）光致电离与时间切片速度映射离子成像（VUV-PI-VMI）检测相结合的 VUV 光解离动力学可以研究 N(2)和 CO(2)。VUV 激光光通过 Kr 中的共振和频混合产生。我们使用 N(2)来证明，当 VUV 激光的光子能量高于一个产物原子的允许跃迁的电离能时，可以检测到它，并随着波长的变化对其进行表征。在这种情况下，在激发 N(2)(o(1)Π(u), v(') = 2, J(') = 2) ← N(2)(X(1)Σ(g) (+), v(") = 0, J(") = 1)后，测量到 N((2)D°)的 β 参数 = 0.57。对 CO(2)的研究表明，当不存在允许跃迁时，可以使用自电离共振来检测产物原子。在这种情况下，首次表明在 92.21nm 处产生了 CO((1)Σ(+))的 O((1)D)原子。这些结果表明，VUV 激光光解离与 VUV-PI-VMI 检测相结合是一种可行的方法，可用于研究在极端紫外线和 VUV 光谱区域内从简单分子的基态进行的单光子光解离。
