The behavior of water molecules at the density of 10¹³ to 10¹⁶ cm⁻³ in a fused silica tube at room temperature has been studied. The number of molecules in the gas phase initially injected in the tube is comparable to the number of molecules adsorbed on the walls of the pre-evacuated tube. The concentrations of molecules in the gas phase were measured by diode laser spectroscopy with an external optical cavity. An off-axis alignment of the cavity with a large set number of transverse modes was used, which made it possible to measure the concentrations of molecules with narrow absorption profiles, temporal resolution of 5 s, and the accuracy better than ±5%. A strong interaction of molecules with the walls was observed. The time behavior of molecules in the gas phase both after the injection of gas into the vacuum volume and after its rapid evacuation under dynamic equilibrium between capture and desorption processes is non-exponential. The characteristic time of these processes 10⁻¹¹ to 10² s depends on the redistribution of molecules between the gas and the near-wall layers, which is governed by the physical and chemical adsorption mechanisms. The theoretical results on the kinetics of the processes are in good agreement with the experimental data.

中文翻译：

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用二极管激光光谱研究水分子与石英管表面的相互作用

水分子在10 ¹³至10 ¹⁶ cm ^-3的密度下的行为在室温下在熔融石英管中进行了研究。最初注入管中的气相分子数量与吸附在预抽空管壁上的分子数量相当。通过具有外部光学腔的二极管激光光谱法测量气相中的分子浓度。使用具有大量设定的横向模式的腔的离轴对准，这使得可以测量具有窄吸收曲线，5 s的时间分辨率和精度优于±5％的分子的浓度。观察到分子与壁的强烈相互作用。在将气体注入真空体积后以及在捕获和解吸过程之间的动态平衡下快速排空后，气相中气相分子的时间行为是非指数的。这些过程的特征时间10^-11至10 ² s取决于气体与近壁层之间分子的重新分布，这取决于物理和化学吸附机制。工艺动力学的理论结果与实验数据吻合良好。