Neutron Diffraction of Large-Volume Samples at High Pressure Using Compact Opposed-Anvil Cells  

作　　者：Xiao-Lin Ni Lei-Ming Fang Xin Li Xi-Ping Chen Lei Duan-Wei He Zi-Li Kou 倪小林;房雷鸣;李欣;陈喜平;谢雷;贺端威;寇自力(Institute of Atomic and Molecular Physics, Sichuan University;Key Laboratory of Neutron Physics and Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics)

机构地区：[1]Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 [2]Key Laboratory of Neutron Physics and Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621999

出　　处：《Chinese Physics Letters》2018年第4期12-15,共4页中国物理快报（英文版）

基　　金：Supported by the National Key Research and Development Program of China under Grant No 2016YFA0401503;the Science Challenge Project under Grant No TZ2016001;the National Natural Science Foundation of China under Grant No 11427810

摘　　要：Neutron diffraction techniques of large-volume samples at high pressure using compact opposed-anvil cells are developed at a reactor neutron source, China＇s Mianyang research reactor. We achieve a high-pressure condition of in situ neutron diffraction by means of a newly designed large-volume opposed-anvil cell. This pressure calibration is based on resistance measurements of bismuth and the neutron diffraction of iron. Pressure calibration experiments are performed at room temperature for a new cell using the tungsten carbide anvils with a tapered angle of 30°, Φ4.5 mm culet diameter and the metal-nonmetal composite gasket with a thickness of 2 mm. Transitions in Bi（Ⅰ–Ⅱ 2.55 GPa, Ⅱ–V 7.7 GPa） are observed at 100 and 300 kN, respectively, by resistance measurements.The pressure measurement results of neutron diffraction are consistent with resistance measurements of bismuth.As a result, pressures up to about 7.7 GPa can routinely and stably be achieved using this apparatus, with the sample volume of 9 mm^3.Neutron diffraction techniques of large-volume samples at high pressure using compact opposed-anvil cells are developed at a reactor neutron source, China＇s Mianyang research reactor. We achieve a high-pressure condition of in situ neutron diffraction by means of a newly designed large-volume opposed-anvil cell. This pressure calibration is based on resistance measurements of bismuth and the neutron diffraction of iron. Pressure calibration experiments are performed at room temperature for a new cell using the tungsten carbide anvils with a tapered angle of 30°, Φ4.5 mm culet diameter and the metal-nonmetal composite gasket with a thickness of 2 mm. Transitions in Bi（Ⅰ–Ⅱ 2.55 GPa, Ⅱ–V 7.7 GPa） are observed at 100 and 300 kN, respectively, by resistance measurements.The pressure measurement results of neutron diffraction are consistent with resistance measurements of bismuth.As a result, pressures up to about 7.7 GPa can routinely and stably be achieved using this apparatus, with the sample volume of 9 mm^3.

关 键 词：Neutron Diffraction of Large-Volume Samples at High Pressure Using Compact Opposed-Anvil Cells 

分 类 号：O571.56[理学—粒子物理与原子核物理]