Development of a miniaturized SQUID measuring systems for an experiment to measure the electric dipole moment of the neutron

开发用于测量中子电偶极矩实验的小型化 SQUID 测量系统

• 批准号: 168225212
• 负责人: Professor Dr. Peter Fierlinger
• 金额: --
• 依托单位: Arbeitsgruppe Hadronenstruktur und Fundamentale Symmetrien
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/168225212?language=en
• 关键词: Development; miniaturized; SQUID; measuring; systems

In a next generation experiment to measure the electric dipole moment of the neutron (nEDM) accurate control of magnetic fields is crucial. In particular, the vertical gradient through the neutron storage chamber needs to be determined precisely to avoid so-called geometric phases, which appear in combination with systematic trajectories of stored ultra-cold neutrons (UCN) in the chamber. Those are interpreted as false EDM Signals and have been observed on the level of 10-26 ecm in the previous generation of experiments. Based on recently developed large volume 3He spin precession chambers, such a gradient can be determined with great accuracy. However, also these 3He chambers must be read out with means of magnetometers. Investigations at PTB Berlin already showed that SQUID magnetic field sensors are best suitable for this purpose, as their noise characteristics at typical precession frequencies (10-50 Hz) are < 2 fT/ . Within the framework of this proposal a miniaturized SQUID System should be developed to read out 3He precession Signals. In addition it should be capable of delivering directional information of magnetic fields in vicinity of the UCN precession chambers and should act as the central component of a 129Xe magnetometer. Next to the use in the nEDM experiment, the new SQUID cryostat potentially has a variety of applications in various fields of research, e.g. biomagnetism.

在测量中子电偶极矩(NEDM)的新一代实验中，磁场的准确控制至关重要。特别是，需要准确确定通过中子储存室的垂直梯度，以避免出现所谓的几何相，这种几何相与储存在储存室中的超冷中子(UCN)的系统轨迹相结合。这些信号被解释为错误的EDM信号，并且在上一代实验中已经在10-26ECM的水平上观察到。基于最近发展起来的大体积3He自旋进动室，这样的梯度可以非常精确地确定。然而，这些3He室也必须用磁力计读出。柏林PTB的研究已经表明，SQUID磁场传感器最适合于此目的，因为它们在典型进动频率(10-50赫兹)下的噪声特性为&lt；2 FT/。在这项提议的框架内，应该开发一个小型的SQUID系统来读出3He进动信号。此外，它应该能够传递UCN进动室附近磁场的方向信息，并应作为129Xe磁强计的中心部件。除了在nEDM实验中的使用外，新的SQUID低温恒温器在各种研究领域都有潜在的应用，例如生物磁学。