Operating principle of the superconducting neutron detector

我们改进了中子探测器的温度稳定性，在5 K时优于80 uK，在使用Cryocon 54的两个控制回路的优化PID条件下，速度误差低于±160 m/s（0.0002%）[1]。这减少了速度误差对探测器边缘附近空间分辨率的影响[2]。在此基础上，我们建立了一个新的低温恒温系统，能够安装室温样品。这与以前在脉冲中子下进行实验的低温恒温器形成了鲜明的对比。特别是，它执行非常高分辨率的成像，因为样品在低温下放置在CB-KID检测器的附近。因此，我们可以在一个单束时间内研究各种样品，如FeS 2菊石，Fe 2 O3菊石，CaF 2 [3]，CuAl-glads，Li Grease，LiPS等。 这也适合于在射束时间期间对样品施加不同的条件，即，温度、电学、压缩牵引力等，以揭示材料的许多特性。我们证实了低熔点伍德金属通过熔化和再凝固的相分离的顺序变化[1]。通过方便的开束归一化，避免了束流不均匀性和硼转换层，使中子图像更加清晰。[1]T. D. Vu等人，物理学杂志：会议系列正在印刷中。[2]T. D. Vu等人，第三届国际工程物理研讨会，IC-MEMS传感器及其应用，胡志明市，越南，2022年11月25日和26日，邀请演讲。[3]H. Shishido，T. D. Vu等人，Journal of Physics：Conference Series in Press.

We improved the stability of temperature of neutron detector better than 80uK at 5K, which gives an error in velocity lower than ±160 m/s (0.0002%) [1] under optimized PID conditions of two control loops using a Cryocon 54. This reduced the influence of velocity error to spatial resolution at near edges of detector [2]. Based on it, we built a new cryostat system to be able to mount room-temperature samples . This is in marked contrast with the former cryostat in conducting the experiments under pulsed neutrons. Especially, it performs a very high-resolution imaging because a sample is placed at the close vicinity of the CB-KID detector at a cryogenic temperature. Therefore, we can investigate various samples in a single beam time such as FeS2 ammonite, Fe2O3 ammonite, CaF2 [3], CuAl-glads, Li Grease, LiPS, etc.. This is also suitable to apply different conditions on sample during beam time, i.e., temperature, electrics, compression traction force, etc. to reveal many properties of material. We confirmed a sequential change in phase separations of low melting Wood’s metal by melting and re-solidification [1]. Neutron image becomes clearer by convenient open-beam normalization to avoid inhomogeneity beam condition and Boron conversion layer.[1] T. D. Vu, et al., Journal of Physics: Conference Series in press.[2] T. D. Vu, et al., The 3rd International Workshop on Engineering Physics, IC-MEMS-Sensors and Their Applications, HCM city, Viet Nam, November 25&26, 2022, Invited talk.[3] H. Shishido, T. D. Vu et al., Journal of Physics: Conference Series in press.