%0 Journal Article
%T ANOMALOUS TRANSMISSION OF X-RAYS UNDER ASYMMETRICAL REFLECTION CONDITION NEAR THE ABSORPTION EDGE<br>吸收限附近非对称反射条件下X射线的异常透射
%A XU ZHANG-CHENG
%A GUO CHANG-LIN
%A ZHAO ZONG-YAN
%A TFUKAMACHI
%A RNEGISHI
%A <br>徐章程
%A 郭常霖
%A 赵宗彦
%A 深町共荣
%A 根岸利一郎
%J 物理学报
%D 1998
%I 
%X Anomalous transmission of X-rays for plance-parallel perfect crystals under asymmetrical Bragg reflection condition near the atomic absorption edge is studied in detail. When diffraction is induced mainly by the imaginary part of atomic scattering factor, the nodes of the standing wave within the crystal lie on the atomic plane at the exact Bragg angle, which results in an anomalous transmission. The transmitted beam comes mainly from the wave-field with its Poynting vector Poynting toward the lower surface of the crystal (the entrance surface being the upper one). The effective absorption coefficient of this wave-field decreases with the asymmetrical factor a. Therefore, the transmitted coefficient of the whole crystal increases as a increases. For a given ratio between the contributions of the real and imaginary parts of atomic scattering factor to diffraction, the deviation of Poynting vector from the normal of the real part of the dispersion surface increases with the degree of asymmetrical reflection condition.
%K X射线
%K 异常透射
%K 原子吸收限
%K 晶体
%K 非对称反射
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=6E709DC38FA1D09A4B578DD0906875B5B44D4D294832BB8E&cid=47EA7CFDDEBB28E0&jid=29DF2CB55EF687E7EFA80DFD4B978260&aid=478BD5F0F36565A6F4FD591B00990950&yid=8CAA3A429E3EA654&vid=F4B561950EE1D31A&iid=708DD6B15D2464E8&sid=F1D2609F60C74576&eid=208A9AB486055DA4&journal_id=1000-3290&journal_name=物理学报&referenced_num=0&reference_num=5