报告题目：Hydrogen permeation through tungsten films -the role of nano-structure and deposition method
报告人：Vincenc Nemanič
报告时间：2013年5月16日（周四） 下午14:00-15:00
报告地点：曹光彪326会议室
联系人：金传洪教授
Vincenc Nemanič简介：
Vincenc Nemanič, (1958) studied physics at University of Ljubljana (Slovenia), where he graduated by thesis “Vacuum thermal insulating panel”. He was formerly employed at Institute for electronics and vacuum technique, where he was a project leader of various R&D tasks related to miniature cathode ray tubes for professional application, miniature dewars for thermal imaging etc. He was faced with problems of generating, focusing and deflection of electron beams, preparing efficient oxide cathodes and vacuum seals required profound understanding of problems related to achievement and maintenance of UHV in small sealed systems. He is currently employed at "Jozef Stefan" Institute, Ljubljana, Slovenia, where he is engaged in three main fields: 1) interaction of hydrogen with metals relevant for fusion, particularly the achieving of ultra-low kinetics of hydrogen evolution from constructional metals, 2) field emission and thermionic emission properties of new nano-structured materials which may become a way for direct conversion of heat into electricity; 3) novel organic core materials for efficient vacuum insulation panels. He is involved in organizing short course vacuum training for various levels organized by the Slovenian Vacuum Society.
In the last 10 years he is co-author of 30 scientific papers in international journals cited by WoS.
报告摘要：
Hydrogen dissolution in the defect-free bulk tungsten is predicted to be endothermic and together with a relatively high diffusion coefficient it results in a rather high permeability. In reality, a tungsten sample consists of multiple grains and grain boundaries which form several defects and hydrogen traps. Their role is most often described as to hinder the diffusion, but published experimental data are very rare and incomplete. New results of long-term outgassing / hydrogen permeation studies of tungsten films deposited on highly permeable Eurofer steel substrates are presented. Four deposition methods were applied and each one gave a different W film structure with a specific permeation flux density determined by traps. So far, their density and their potential influence on the permeability have not been correlated. Present findings have a high relevance to the tritium retention in future fusion reactors like ITER, where similar films could be formed, as a result of plasma exposure, on any cooled chamber wall.
