Research School of Physical Sciences and Engineering, The Australian National University, Canberra, Australian Capital Territory 0200, Australia.
J Chem Phys. 2009 Nov 21;131(19):194308. doi: 10.1063/1.3257690.
Oscillator strengths of 23 electric-dipole-allowed bands of (14)N(2) in the 86.0-89.7 nm (111,480-116,280 cm(-1)) region are reported from synchrotron-based photoabsorption measurements at an instrumental resolution of 6.5x10(-4) nm (0.7 cm(-1)) full width at half maximum. The absorption spectrum comprises transitions to vibrational levels of the c(n) (1)Pi(u) (n=3,4), o(3) (1)Pi(u), and c(n+1)(') (1)Sigma(u)(+)(n=3,4) Rydberg states as well as the b (1)Pi(u) and b(') (1)Sigma(u)(+) valence states. The J dependences of band f-values derived from the experimental line f-values are reported as polynomials in J(J+1) and are extrapolated to zero nuclear rotation in order to facilitate comparisons with the results of coupled Schrodinger equation calculations. Many bands in this study are characterized by a strong J dependence of the band f-values and display anomalous P-, Q-, and R-branch intensity patterns. Predissociation line widths are reported for six bands. The experimental f-value and line-width patterns inform current efforts to develop comprehensive spectroscopic models for N(2) that incorporate rotational effects and predissociation mechanisms, and are critical for the construction of realistic atmospheric radiative-transfer models.
报道了在仪器分辨率为 6.5x10(-4)nm（0.7cm(-1)) 半峰全宽的同步加速器基光电吸收测量中，在 86.0-89.7nm（111480-116280cm(-1)) 区域内（14)N(2) 的 23 条电偶极允许带的振子强度。吸收光谱包括跃迁到 c(n)（1）Pi(u)（n=3，4)、o(3)（1）Pi(u)和 c(n+1)(')（1）Sigma(u)(+)Rydberg 态的振动能级，以及 b（1）Pi(u)和 b(')（1）Sigma(u)(+)价态。从实验线 f 值得出的带 f 值的 J 依赖性作为 J（J+1）的多项式报告，并外推到零核旋转，以便于与耦合薛定谔方程计算的结果进行比较。本研究中的许多带都表现出带 f 值的强烈 J 依赖性，并显示出异常的 P、Q 和 R 支强度模式。报道了六条带的预解离线宽。实验 f 值和线宽模式为目前开发包含旋转效应和预解离机制的 N(2)综合光谱模型的努力提供了信息，并且对于构建现实的大气辐射转移模型至关重要。
