A focusing-geometry small-angle neutron scattering instrument with a magnetic neutron lens
A focusing-geometry small-angle neutron scattering instrument with a magnetic neutron lens
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一种带磁中子透镜的聚焦几何小角中子散射仪
DOI：
10.1107/s0021889807003822
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发表时间：
2007
影响因子：
6.1
通讯作者：
H. Shimizu
中科院分区：
文献类型：
--
作者：
T. Oku;H. Iwase;T. Shinohara;S. Yamada;K. Hirota;S. Koizumi;J. Suzuki;T. Hashimoto;H. Shimizu
我们利用两种中子聚焦装置--系列镁氟化物复合折射透镜和基于扩展Halbach六极磁铁的磁中子透镜，搭建了一台聚焦几何小角中子散射仪SANS-J-II。在这项研究中，我们研究了使用磁中子透镜的FSANS仪器的性能。对于偏振度为sim 0.99的偏振中子束，磁中子透镜聚焦在探测器平面上的直接中子束的强度分布具有峰值高度与本底能级之比为sim 6×10 4。结果表明，用磁中子透镜的FSANS仪器可以获得6.5×10-4 A−1的可测Q范围[式中Q是散射向量的模数，定义为Q=(4pi/lambda)sin(theta/2，其中theta是散射角，lambda是中子波长])，Q_rmmin为6.5×10-4 。
We have constructed a focusing-geometry small-angle neutron scattering (FSANS) instrument, SANS-J-II, with two kinds of neutron focusing device: a series of compound refractive lenses made of MgF2 and a magnetic neutron lens based on an extended Halbach-type sextupole magnet. In this study, we investigated the performance of the FSANS instrument with the magnetic neutron lens. The intensity distribution of a direct neutron beam focused on the detector plane by the magnetic neutron lens had a ratio of the peak height to the background level of \sim\!6\times 10^4 for a polarized neutron beam with a polarization degree of \sim \!0.99. It is found that a minimum value of the measurable q range [where q is the modulus of the scattering vector and is defined as q = (4\pi/\lambda)\sin(\theta/2), where \theta is the scattering angle and \lambda is the neutron wavelength], q_{\rm min}, of 6.5 \times 10^{-4} A−1 can be achieved by the FSANS instrument with the magnetic neutron lens using neutrons with \lambda = 6.6 A and \Delta \lambda/\lambda = 0.13 for the full width at half maximum.