Physique des Interactions Ioniques et Moléculaires, CNRS and Université d'Aix-Marseille, UMR7345, Campus de Saint Jérôme, service 242, F-13397 Marseille Cedex 20, France.
J Phys Condens Matter. 2013 Jun 5;25(22):225002. doi: 10.1088/0953-8984/25/22/225002. Epub 2013 Apr 18.
Recent experiments with nitrogen as a seeding gas in fusion plasma devices together with the option of using beryllium as an armor material in the future ITER tokamak (International Thermonuclear Experimental Reactor) have raised new interest in the interactions of beryllium surfaces with nitrogen (atomic or molecular). The strong reactivity of nitrogen implies the formation of beryllium nitrite and, in conjunction with oxygen and other possible impurities, experimentalists have to consider the probability of generating various complex moieties such as imine, amine or oxyamine, and amide radicals. This chemistry would obviously dramatically perturb the plasma, and quantum investigations can be of great predictive help. Nitrogen adsorption on beryllium basal surfaces is investigated through quantum density functional theory. Different situations are examined: molecular or atomic nitrogen reactions; nitride radical adsorption or formation on surfaces; hydrogen retention on surfaces; combined nitrogen/oxygen reactivity and hydrogen retention. A tentative comparison with experiment is also proposed.
最近在聚变等离子体装置中使用氮作为种子气体的实验，以及未来 ITER 托卡马克（国际热核聚变实验堆）中使用铍作为装甲材料的选择，引起了人们对氮（原子或分子）与铍表面相互作用的新兴趣。氮的强反应性意味着形成氧化亚铍，并且与氧和其他可能的杂质结合，实验人员必须考虑生成各种复杂基团的可能性，如亚胺、胺或氧胺和酰胺自由基。这种化学显然会剧烈地扰乱等离子体，而量子研究可以提供很大的预测帮助。通过量子密度泛函理论研究了氮在铍基面的吸附。考察了不同的情况：分子或原子氮的反应；氮化物自由基在表面上的吸附或形成；表面上的氢保留；氮/氧的综合反应和氢保留。还提出了与实验的初步比较。
