Ultrasensitive 3He magnetometer for measurements of high magnetic fields
Ultrasensitive 3He magnetometer for measurements of high magnetic fields
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DOI：
10.1140/epjd/e2014-50401-3
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发表时间：
2014-11-03
影响因子：
1.8
通讯作者：
Terekhov, Maxim
中科院分区：
文献类型：
--
作者：
Nikiel, Anna;Bluemler, Peter;Terekhov, Maxim
我们描述了一种He-3磁强计，它能够测量高磁场（B > 0.1 T），相对精度优于10（-12）。我们的方法是基于测量的气体，核自旋极化的He-3的自由感应衰变的共振射频脉冲激发。测量的灵敏度可以归因于长相干自旋进动时间T-2* 的数量级分钟，这是实现了球形样品细胞在政权的“运动变窄”，其中的干扰影响的字段不均匀性被强烈抑制。He-3气体的自旋极化原位使用一种新的，非标准的变体的亚稳态交换光泵浦。我们表明，小型化有助于进一步增加T-2*，并且测量灵敏度不受10（-4）阶时间场波动的显著影响。
We describe a He-3 magnetometer capable to measure high magnetic fields (B > 0.1 T) with a relative accuracy of better than 10(-12). Our approach is based on the measurement of the free induction decay of gaseous, nuclear spin polarized He-3 following a resonant radio frequency pulse excitation. The measurement sensitivity can be attributed to the long coherent spin precession time T-2* being of order minutes which is achieved for spherical sample cells in the regime of "motional narrowing" where the disturbing influence of field inhomogeneities is strongly suppressed. The He-3 gas is spin polarized in situ using a new, non-standard variant of the metastability exchange optical pumping. We show that miniaturization helps to increase T-2* further and that the measurement sensitivity is not significantly affected by temporal field fluctuations of order 10(-4).