Collisional broadening and pressure shift parameters for the potassium resonance doublet, near 770 nm, are reported for collisions with molecular oxygen and carbon dioxide. Experiments were conducted in a reflected shock tube from 1200–2200 K and used potassium chloride (KCl) salt as the atomic potassium source. The measured absorption lineshapes were fit with Voigt profiles to infer the collisional broadening and pressure shifts. Power-law correlations were then developed to describe the pressure-normalized results as functions of temperature. Generally, the collisional broadening coefficients in oxygen agree well with theoretical predictions and are similar to those in nitrogen. Conversely, the pressure shift coefficients in oxygen differ from those in nitrogen by up to 15%. Broadening coefficients in carbon dioxide disagree with theoretical predictions by 20% or more over the range of temperatures explored in this work. These results expand the existing database of potassium lineshape coefficients, and they are expected to be useful for further development of potassium sensing diagnostics in terrestrial, Martian, and Venusian atmospheric flight studies, and in combustion systems. Other anticipated applications include interpretation of astrophysical spectroscopic observations.

中文翻译：

---

高温下氧气和二氧化碳中钾 D1 和 D2 跃迁的碰撞展宽和压力转移系数


据报道，钾共振双峰在 770 nm 附近与分子氧和二氧化碳碰撞时的碰撞展宽和压力变化参数。实验在 1200-2200 K 的反射激波管中进行，并使用氯化钾 (KCl) 盐作为原子钾源。测量的吸收线形与 Voigt 剖面拟合，以推断碰撞展宽和压力变化。然后开发幂律相关性来将压力归一化结果描述为温度的函数。一般来说，氧气中的碰撞展宽系数与理论预测非常吻合，并且与氮气中的碰撞展宽系数相似。相反，氧气中的压力变化系数与氮气中的压力变化系数最多相差 15%。在本工作探索的温度范围内，二氧化碳的展宽系数与理论预测相差 20% 或更多。这些结果扩展了钾线形系数的现有数据库，预计将有助于进一步开发陆地、火星和金星大气飞行研究以及燃烧系统中的钾传感诊断。其他预期的应用包括天体物理光谱观测的解释。