Kerber R L, Hough J J
Appl Opt. 1978 Aug 1;17(15):2369-80. doi: 10.1364/AO.17.002369.
A rate equation model of a pulsed H(2) + F(2) chemical laser is used to examine the relative importance of rotational nonequilibrium mechanisms on laser performance. This computer model yields the time history of the first thirteen rotational levels and the first twelve vibrational-rotational P-branch transitions for the first six vibrational bands of HF. With this model, the general effects of rotational nonequilibrium on the H(2) + F(2) laser were found (1) to increase the number of transitions that lase simultaneously, (2) to lower the intensity of each transition, and (3) to extend the duration of lasing on each transition; these trends are similar to those observed earlier for the F + H(2) laser. The major thrust of the present work is to isolate the relative importance of the various rotational nonequilibrium mechanisms. To this end, we have examined and compared several approaches to modeling R-T and V-R relaxation, nonequilibrium pumping distributions, and line-selected operation. The effects of these mechanisms (and their relative importance) on the laser output are clearly revealed by the model. The character of the spectra for the H(2) + F(2) model is significantly different from that observed for the F + H(2) model. The ability of the model to predict spectra observed in experiments is assessed, and the model is found to compare well with discharge-initiated lasers. Additional calculations demonstrate the effect of multiquanta V-T deactivation of HF by HF.
一个脉冲H₂ + F₂化学激光器的速率方程模型被用于研究转动非平衡机制对激光性能的相对重要性。这个计算机模型能够给出HF前六个振动带中前13个转动能级以及前12个振转P支跃迁的时间历程。利用这个模型，发现转动非平衡对H₂ + F₂激光器的总体影响为：（1）增加同时激射的跃迁数量；（2）降低每个跃迁的强度；（3）延长每个跃迁的激射持续时间；这些趋势与早期在F + H₂激光器中观察到的相似。当前工作的主要重点是确定各种转动非平衡机制的相对重要性。为此，我们研究并比较了几种模拟R - T和V - R弛豫、非平衡抽运分布以及选线操作的方法。该模型清楚地揭示了这些机制（及其相对重要性）对激光输出的影响。H₂ + F₂模型的光谱特征与F + H₂模型中观察到的显著不同。评估了该模型预测实验中观察到的光谱的能力，发现该模型与放电引发的激光器的比较结果良好。额外的计算证明了HF对HF的多量子V - T去活化的影响。
