Very precise detection of spin fluctuation by polarized neutrons

采用极化中子导轨(PNG)的新概念，为国家高能所助推器同步加速器利用装置的顶能谱仪设计了一套中子偏振器。PNG由直形导镍管和Fe/Si超镜偏振器组成，在中子导中呈V形。它的性能已经在TOP光谱仪上进行了研究。结果表明，PNG对脉冲冷中子的处理效果很好，与以前的Co/Ti Soller偏振导偏振器相比，它提供的偏振中子是极化中子的两倍，而且偏振性能更好。在东海建立JAERI时，JRR-3M上6G TOPAN光谱仪的偏振分析选项已经准备完毕，现在可以使用。然而，我们仍然在继续尝试通过对偏振单色仪和分析仪的Heusler晶体进行热处理来获得具有更好偏振特性的偏振中子。

A neutron polarizer has been designed for the TOP spectrometer at Booster Synchrotron Utilization Facility at National institute of High Energy Physics by a new concept of polarizing neutron guide (PNG). The PNG consists of straight Ni guide tubes and Fe/Si supermirror polarizers which make V-shape in the neutron guide. Its performance has been studied on the TOP spectrometer. It is revealed that PNG works very well with pulsed cold neutrons and that it provides twice as much as polarized neutron with better polarization compared with the previous polarizer of Co/Ti Soller polarizing guide.Preparation of polarization analysis option on TOPAN spectrometer at 6G in JRR-3M at the Tokai establishment of JAERI has been completed and now ready for use. However, we still continue to try to get polarized neutrons with better polarization by heat treatment of Heusler crystals of polarizing monochorometer and analyzer.