Gvaramia Manuchar, Gutfreund Philipp, Falus Peter, Faraone Antonio, Nagao Michihiro, Wolff Max
Department for Physics and Astronomy, Uppsala University, Regementsvägen 1, SE-75120, Uppsala, Sweden.
Institut Laue-Langevin, CS 20156, 38042, Grenoble Cedex 9, France.
Sci Rep. 2023 Aug 11;13(1):13051. doi: 10.1038/s41598-023-39854-4.
Neutron spin echo spectroscopy is a high resolution inelastic neutron scattering method probing nanosecond dynamics. It is well suited to study the atomistic motion in polymer systems and contributes to our understanding of viscoelasticity. However, for samples under shear, or moving samples in general, Doppler scattering has to be considered. We compare the measured phase shift and depolarisation due to Doppler scattering from a rotating graphite disk to numerical and analytical calculations and find excellent agreement. This allows to take into account Doppler scattering during the data processing and makes longer Fourier times as well as higher shear rates and Q ranges possible with neutron spin echo spectroscopy, enabling for example the study of polymers under high shear.
中子自旋回波光谱是一种探测纳秒动力学的高分辨率非弹性中子散射方法。它非常适合研究聚合物体系中的原子运动，有助于我们理解粘弹性。然而，对于受剪切的样品或一般的移动样品，必须考虑多普勒散射。我们将旋转石墨盘的多普勒散射所测量的相移和去极化与数值计算和解析计算进行比较，发现吻合度极佳。这使得在数据处理过程中能够考虑多普勒散射，并使中子自旋回波光谱能够实现更长的傅里叶时间以及更高的剪切速率和Q范围，例如能够研究高剪切下的聚合物。
