论文标题
直接确定OH自由基在水冰上扩散的活化能
Direct Determination of the Activation Energy for Diffusion of OH Radicals on Water Ice
论文作者
论文摘要
利用光刺激的呼吸和共振增强的多光子电离方法的结合，在54至80 K之间的温度下，监测了OH自由基表面上的OH自由基的行为。使用Arrhenius方程，可以通过两个OH自由基的重组来解释降低，这是OH的热扩散速率限制的。首次在实验中确定表面扩散的活化能为0.14 +/- 0.01 eV，该EV大于理论模型中假定的激活能量。该值表明，在星际冰上，OH自由基的扩散反应开始在约36 K处激活。
Using a combination of photostimulated desorption and resonance-enhanced multiphoton ionization methods, the behaviors of OH radicals on the surface of interstellar ice analog was monitored at temperatures between 54 and 80 K. The OH number density on the surface of ultraviolet (UV)-irradiated compact amorphous solid water gradually decreased at temperatures above 60 K. Analyzing the temperature dependence of OH intensities with the Arrhenius equation, the decrease can be explained by recombination of two OH radicals, which is rate-limited by thermal diffusion of OH. The activation energy for surface diffusion was experimentally determined for the first time to be 0.14 +/- 0.01 eV, which is larger than or equivalent to those assumed in theoretical models. This value implies that the diffusive reaction of OH radicals starts to be activated at approximately 36 K on interstellar ice.
