Ezperimental Studies for Moderation Property of Solid Neon Moderator

摘要：

Slow positron beams are of interest as a probe for surface and interface of materials investigation. A positron beam system that has high moderation efficiency has been constructed in Wuhan University. This positron beam that transported by magnetic field, using high moderation efficiency solid Neon as moderator is fit for small laboratory (e.g. University). This paper reports the experimental studies for moderation property of solid Neon moderator under the different moderators growing condition. The results show that slow positron flux is 6.79×106e+/s for 42mCi 22Na radioactive isotope and the moderation efficiency of solid Neon (about 1％) is decuple to tungsten (a conventional moderator). A moderator with high stability can be achieved under certain condition as growth temperature is 8.5K, the flux of Neon gas is 3.0 SCCM and time of annealing is 3000sec. Calculated decay coefficient of moderator is only 2％ per day.

关键词： Slow positron beam Solid Neon Moderator Moderation property

作者: Y.Q.Chen S.J.Wang C.Q.Chen Y.C.Wu Z.Q.Chen H.J.Zhang

作者单位: Key Lab of Nuclear Solid State Physics of Hubei Province,and Department of Physics,Wuhan University,Wuhan 430072,Peoples Republic of China

会议类型: 国际会议

会议名称: 第九届国际正电子与正电子素国际会议(9th International Workshop on Positron and Positronium Chemistry)(PPC–9)

会议地点: 武汉

会议语种:英文

页码: 95

在线出版日期: 2008-05-11（万方平台首次上网日期，不代表论文的发表时间）