基于冷中子谱的紧凑型中子自旋倒相器设计

为节省极化中子散射谱仪传输光路的空间，实现特定冷中子谱的极化中子高效率自旋翻转，使用在空间上自然衰减的前端多层膜极化器静磁场作为中子自旋倒相器的导向磁场，在空间上形成了紧凑型冷中子自旋倒相器设计模型。介绍了实际模型物理参数的计算方法。对前端极化器静磁场在空间上的自然衰减进行了实验测试，根据测试结果及拟使用冷中子波段，针对设计的紧凑型中子自旋倒相器的相关参数进行了优化计算。模拟了极化中子在实际复合磁场中的自旋翻转图像，计算了自旋倒相器的翻转效率。对设计的紧凑型中子自旋倒相器进行了翻转效率物理实验测试，测试结果表明：设计的中子自旋倒相器翻转效率可在99.2%以上，达到了预期设计指标，可用于极化冷中子散射谱仪。

Design of compact neutron spin flipper based on cold neutron spectrum

In order to save the limited space of polarized neutron scattering spectrometer and realize the high efficiency spin flip for the given energy band cold neutrons .A compact neutron flipper is established using the spontaneous attenuation magnetic field of polarizer as gradient magnetic field .The real calculation method is introduced , and spontaneous attenuation data of gradient magnetic field along the neutron beam flight is meas -ured.Based on the real neutron wave band and workable dimension , the key parameters and flip probability for neutron flipper are calculated , and the distribution of neutron spin projection on the real magnetic field along the spin flipper is simulated .Finally, the measurement is done and the correction of the designed neutron flipper is discussed as well .Experimental results indicate that the flip probability can reach over 99.2%.The designed neutron spin flipper can satisfy the anticipant requirements , which can be used for construction of po-larized neutron scattering instruments .