Operating principle of the superconducting neutron detector

利用Cryocon 54优化了两个控制回路的PID条件，使中子探测器在5K时的温度稳定性优于80uK，速度误差小于±160 m/s(0.0002%)[1]。这降低了速度误差对探测器[2]近边缘空间分辨率的影响。在此基础上，我们建立了一个新的低温恒温系统，可以安装室温样品。这与以前的低温恒温器在脉冲中子下进行实验有明显的对比。特别是，由于样品在低温下放置在CB-KID探测器附近，因此它可以执行非常高分辨率的成像。因此，我们可以在单束时间内研究各种样品，如FeS2氨石、Fe2O3氨石、CaF2[3]、CuAl-glads、Li Grease、LiPS等。这也适用于在光束时间内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。我们通过熔炼和再凝固[1]证实了低熔点木材金属相分离的顺序变化。通过方便的开束归一化，避免了光束的不均匀性和硼转换层，使中子图像更加清晰吴廷德，等，物理学报：会议丛刊，2010吴廷德等，第三届工程物理，ic - mems传感器及其应用国际研讨会，越南胡志明市，2022年11月25 - 26日，特邀演讲H. Shishido， T. D. Vu等，物理学报：会议系列出版。

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.