A High Resolution Disk Chopper with Two-Stage Rotors for Neutron Time-of-Flight Spectroscopy

目标是建立安装在京都大学研究堆（5兆瓦，轻水慢化）超镜中子引导大厅的四种布拉格散射装置的新版本：也就是说，三个装置是飞行时间衍射仪与点探测器使用中子从磁盘切碎器（TOF），其余的设置是一个晶体衍射仪与两个一维位置敏感探测器使用中子从热解石墨单色仪（PSD）。TOF系统：基于中子透射率的计算，设计并构造了一种新型的两级转子盘状斩波器。该光谱仪于1996年11月建立后，对标准样品Fe-Cr-Ni， α / γ两相钢进行了优化，并提供给日本大学研究人员的常用研究。(1)性能测试：(1)-1。中子的波长分辨率和强度分别提高了2.5倍和3.3倍，使衍射仪的性能提高了约8倍。对α / γ钢和SiCw/Al样品进行了测试，验证了晶格规格在10^<-3>至10^<-4>范围内的应变测量结果。2. psd系统：采用i) 3x30x200, ii) 4x30x200和iii) 4x30x200两层（mm） Si单晶（311），对单色仪装置进行优化。用中子成像板法对单色中子的束谱进行了表征。中子的绝对值用金箔活化法测定。用α Fe标准样品对系统进行了性能测试。(2)性能测试：(2)-1。得到了α Fe（211）的准平行衍射图，FWHM为11.4'，与预测一致。该晶体的角分辨率和衍射强度比传统的热解石墨单色仪提高了10-15倍。少

The objectives are to establish the novel version of the four kinds of Bragg scattering set-ups installed at the supermirror neutron guide hall in Kyoto University Research Reactor (5 MW,light water moderated) : i.e.the three set-ups are time-of-flight diffractometers with point detectors using neutrons from a disk chopper (TOF), and the rest set-up is a crystal diffractometer with two one-dimensional position sensitive detectors with use of neutrons from a pyrolytic graphite monochromator (PSD).1.TOF System : A novel disk chopper with two-stage rotors was designed and constructed based on the calculation of neutron transmission probability. The spectrometer was optimized with the measurements of standard sample Fe-Cr-Ni, alpha/gamma two phase steel, and supplied for the common studies by researchers from universities in Japan after its establishment, Nov.1996.(1)Performance Tests :(1)-1.Neutron wavelength resolution and its intensity became 2.5 and 3.3 times highe, resulting about 8 t … More imes improvement of the diffractometer.(1)-2.The samples of alpha/gamma steels and SiCw/Al were examined to verify the strain measurements of the crystal lattice specings over 10^<-3> to 10^<-4>. The gauge volume defined by the slit system before and after the sample was 2x30 in mm.2.PSD System : The several Si single crystals (311), i) 3x30x200, ii) 4x30x200 and iii) 4x30x200, two layrs (in mm), were used for the optimization of the monochromator device. The beam profiles of the monochromatic neutrons were characterized by the Neutron Imaging Plate method. The absolute value of the neutrons was determined by the Au-foil Activation method. The performance tests of the ststerm were carried out with the standard samples of alpha Fe.(2) Performance Tests :(2)-1.The quasi-parallel diffraction pattern from alpha Fe (211) was obtained and its FWHM was 11.4' which was consistent with the prediction.(2)-2.The angular resolution and the diffraded intensity were improved to be 10-15 times higher with repect to the conventional mosaic crystal of pyrolytic graphite monochromator. Less