共查询到18条相似文献,搜索用时 187 毫秒
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目前,北京同步辐射装置4W1A束线的双晶单色器存在着调节困难、单色光出口不固定等问题,本对其中原因进行了讨论,并提出一种新型结构的双晶单色器。此单色器具有调节简单、波长切换方便等优点,并实现了单色光固定出口。从而能够大大缩短调光时间,提高4W1A束线专用光的用光效率。 相似文献
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利用光强反馈提高上海光源BL15U线站光束位置的稳定性 总被引:1,自引:0,他引:1
上海光源(SSRF)硬X射线微聚焦线站(BL15U)利用光强反馈的方法提高了光束位置的稳定性。反馈控制系统由光束线光强探测器和双晶单色器第二晶体的投角(pitch2)微调机构组成,通过调节pitch_2,使光强达到并保持在最大值,消除由单色器双晶、平行度变化造成的光束位置不稳定。实验结果表明,加入反馈后显著抑制了频率10 Hz以下的垂直方向光束位置晃动,将能量扫描时光束位置的稳定性提高了5倍以上。采用反馈系统后,样品台处光斑垂直方向的不稳定性得到显著控制,达到预期效果。 相似文献
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CAOChong-Zhen GAOXue-Guan MAPei-Sun WANGFeng-Qin HEDong-Qing HUANGYu-Ying LIUPeng 《核技术(英文版)》2005,16(2):85-89
In a fine adjustment mechanism of the second crystal in a double-crystal monochromator, a compression spring is usually used as a return force element, but it often produces permanent deform after some time. A novel fine adjustment mechanism is put forward, which utilizes permanent-magnet as the return force element instead of a compression spring. Its principle and advantages of adjusting the pitch angle and the roll angle are analyzed, and the structure parameters of the permanent-magnet, which is the key part of the fine adjustment mechanism, are optimized. The magnetically adsorbed fine adjustment mechanism has been testified and applied successfully in the double-crystal monochromator of 4W1B beam line in Beijing Synchrotron Radiation Facility (BSRF). 相似文献
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中子能量选择成像作为一种前沿中子成像技术,可实现传统白光中子照相技术无法实现的功能,如研究工程材料中的晶粒分布、应变/应力分布、织构测量和相变分析等。本文依托中国先进研究堆(CARR)上的中子成像测试平台,在国内首次研制了石墨双晶单色器,建立能量选择中子成像技术。飞行时间实验测试结果表明,该双晶石墨单色器在选择4×10-10 m的中子时波长分辨率可达2.6%,优于3.0%的设计指标。虽然在冷源未开启的实验条件下该石墨双晶单色器产生了较多的次级中子,但基于现有条件开展的镍基高温合金的中子能量选择成像实验能清楚分辨特定取向微晶粒的形貌及分布。结果表明研制的石墨双晶单色器可在CARR上开展能量选择成像实验,随着未来CARR冷源的开启,次级中子数量降低,中子束流品质进一步提高,将开展高质量的中子能量选择成像实验。 相似文献
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《Annals of Nuclear Energy》1999,26(16):1447-1455
The purpose of this work is to develop a selection process for natural crystals that considers the major characteristics and performance as gratings for neutron monochromator and analyzers using the neutron diffraction technique. From the 350 naturally occurring types, 19 crystals have been selected and classified regarding their adequacy for use as neutron diffraction devices. Applying special criteria, method and with the help of the rocking curve determination technique, the measurements were established and the theoretically available values were confronted with experimental results, obtained directly from a Neutron Diffractometer, in operation at the IPEN-R1 (5 MW) nuclear research reactor. Natural occurring crystals allow the use of greater values of interplanar distance, providing measurements in the subthermal neutron energy range. The performance of the Merit Figure, introduced to evaluate the neutron reflectivity, was considered effective regarding the nuclear properties of the component crystalline materials. A total of 12 natural types and the respective main families of planes for neutron diffraction, which have affirmed their theoretical-experimental performance, were appointed for routine applications for complementary use together with the conventional-artificial crystals. 相似文献