Fluxgate magnetometers are important tools for geophysics and space physics, providing high-precision magnetic field measurements. Fluxgate magnetometer noise performance is typically limited by a ferromagnetic element that is periodically forced into magnetic saturation to modulate, or gate, the local magnetic field. The parameters that control the intrinsic magnetic noise of the ferromagnetic element remain poorly understood. Much of the basic research into producing low-noise fluxgate sensors was completed in the 1960s for military purposes and was never publicly released. Many modern fluxgates depend on legacy Infinetics S1000 ring cores that have been out of production since 1996 and for which there is no published manufacturing process. We present a manufacturing approach that can consistently produce fluxgate ring cores with a noise of ∼6–11 pT per square root hertz – comparable to many of the legacy Infinetics ring cores used worldwide today. As a result, we demonstrate that we have developed the capacity to produce the low-noise ring cores essential for high-quality, science-grade fluxgate instrumentation. This work has also revealed potential avenues for further improving performance, and further research into low-noise magnetic materials and fluxgate magnetometer sensors is underway.

中文翻译：

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用于磁通门磁力计的低噪声坡莫合金环形磁芯

Fluxgate磁力计是用于地球物理学和空间物理学的重要工具，可提供高精度的磁场测量。磁通门磁力计的噪声性能通常受到铁磁元件的限制，该铁磁元件会定期被迫进入磁饱和状态，以调制或控制局部磁场。控制铁磁元件固有磁噪声的参数仍然知之甚少。生产低噪声磁通门传感器的许多基础研究已于1960年代出于军事目的完成，并且从未公开发布。许多现代磁通门都依赖于自1996年以来就已经停产并且尚未发布制造工艺的Infinetics S1000环形磁芯。我们提出了一种制造方法，该方法可以始终如一地生产出噪声为每平方根赫兹约6 –11 pT –与当今世界范围内使用的许多传统Infinetics环形磁芯相当。结果表明，我们已经开发出了生产高质量科学级磁通门仪器必不可少的低噪声环形磁芯的能力。这项工作还揭示了进一步提高性能的潜在途径，并且正在进行对低噪声磁性材料和磁通门磁力计传感器的进一步研究。