Li Fankang, Feng Hao, Thaler Alexander N, Parnell Steven R, Hamilton William A, Crow Lowell, Yang Wencao, Jones Amy B, Bai Hongyu, Matsuda Masaaki, Baxter David V, Keller Thomas, Fernandez-Baca Jaime A, Pynn Roger
Instrument and Source Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Center for Exploration of Energy and Matter and Department of Physics, Indiana University, Bloomington, IN, 47408, USA.
Sci Rep. 2017 Apr 13;7(1):865. doi: 10.1038/s41598-017-00740-5.
The neutron Larmor diffraction technique has been implemented using superconducting magnetic Wollaston prisms in both single-arm and double-arm configurations. Successful measurements of the coefficient of thermal expansion of a single-crystal copper sample demonstrates that the method works as expected. The experiment involves a new method of tuning by varying the magnetic field configurations in the device and the tuning results agree well with previous measurements. The difference between single-arm and double-arm configurations has been investigated experimentally. We conclude that this measurement benchmarks the applications of magnetic Wollaston prisms in Larmor diffraction and shows in principle that the setup can be used for inelastic phonon line-width measurements. The achievable resolution for Larmor diffraction is comparable to that using Neutron Resonance Spin Echo (NRSE) coils. The use of superconducting materials in the prisms allows high neutron polarization and transmission efficiency to be achieved.
已使用超导磁沃拉斯顿棱镜以单臂和双臂配置实现了中子拉莫尔衍射技术。对单晶铜样品热膨胀系数的成功测量表明该方法按预期工作。该实验涉及一种通过改变装置中的磁场配置进行调谐的新方法，且调谐结果与先前的测量结果吻合良好。已通过实验研究了单臂和双臂配置之间的差异。我们得出结论，该测量为磁沃拉斯顿棱镜在拉莫尔衍射中的应用提供了基准，并且原则上表明该装置可用于非弹性声子线宽测量。拉莫尔衍射可实现的分辨率与使用中子共振自旋回波（NRSE）线圈的分辨率相当。在棱镜中使用超导材料可实现高中子极化和传输效率。
