A new cryogenic apparatus to search for the neutron electric dipole moment
A new cryogenic apparatus to search for the neutron electric dipole moment
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DOI：
10.1088/1748-0221/14/11/p11017
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发表时间：
2019-11-01
影响因子：
1.3
通讯作者：
Young, A. R.
中科院分区：
文献类型：
--
作者：
Ahmed, M. W.;Alarcon, R.;Young, A. R.
本文介绍了一种低温装置，它使得一项名为nEDM@SNS的新实验得以开展。与当前寻找中子电偶极矩（EDM）的灵敏度极限相比，该实验的灵敏度有了重大提升。此装置利用超流氦 - 4产生高密度的超冷中子（UCN），这些超冷中子被置于一对经过适当涂层处理的测量池中。该实验将在橡树岭国家实验室的散裂中子源处进行，实验中，来自原子束源的极化氦 - 3被注入超流氦 - 4中，并传输至测量池，在那里极化氦 - 3用作共磁强计。与以往实验相比，超流氦 - 4还被用作绝缘介质，使得测量池两端能够维持显著更高的电场。这些特性使得中子电偶极矩测量的最终统计不确定度达到2 - 3×10⁻²⁸ e - cm，预计系统不确定度低于这一水平。
A cryogenic apparatus is described that enables a new experiment, nEDM@SNS, with a major improvement in sensitivity compared to the existing limit in the search for a neutron Electric Dipole Moment (EDM). This apparatus uses superfluid He-4 to produce a high density of Ultra-Cold Neutrons (UCN) which are contained in a suitably coated pair of measurement cells. The experiment, to be operated at the Spallation Neutron Source at Oak Ridge National Laboratory, uses polarized He-3 from an Atomic Beam Source injected into the superfluid He-4 and transported to the measurement cells where it serves as a co-magnetometer. The superfluid He-4 is also used as an insulating medium allowing significantly higher electric fields, compared to previous experiments, to be maintained across the measurement cells. These features provide an ultimate statistical uncertainty for the EDM of 2 - 3 x 10(-28) e-cm, with anticipated systematic uncertainties below this level.