【摘要】 为了获得氧与铀初期反应的动力学性质,实验利用表面吸附分析系统,采用微压PVT方法研究了O2在清洁铀表面的初期吸附反应行为,测量了饱和吸附量和反应概率。结果表明,氧的吸附量趋近一个极大值,约4.3×1015/cm2,粘附概率起初随吸附量增加缓慢减少;氧在清洁铀表面迅速解离,与表面铀原子反应生成氧化物,氧离子扩散通过氧化物层,继续与界面处的铀原子发生反应;气体初期反应动力学进程依赖于表面反应产物的组成和厚度变化对分子解离和离子扩散过程的影响。更多还原

【Abstract】 The saturation capacity and reaction probability of O2 adsorption on clean uranium surface have been quantitatively measured by low pressure PVT method,and their reactivity and kinetic property were obtained.The experimental results show that O2 exhibited the reaction characteristics of adsorbed gas amount(coverage) is approaching a maximum value,about 4.3×1015/cm2 and reaction probability is decreasing with a rise in adsorbed gas amount.Oxygen molecule on the clean uranium is dissociated rapidly,reacted to form oxide with exterior uranium atom.Oxygen particles diffuse to pass through oxide layer and react with uranium atom at interface.The initial reaction kinetics relies on the impacts of both product layer composition and thickness on the molecular dissociation and dissociative particles diffusion process.更多还原