Micromagnetic tomography aims at reconstructing large numbers of individual magnetizations of magnetic particles from combining high‐resolution magnetic scanning techniques with micro X‐ray computed tomography (microCT). Previous work demonstrated that dipole moments can be robustly inferred, and mathematical analysis showed that the potential field of each particle is uniquely determined. Here, we describe a mathematical procedure to recover higher orders of the magnetic potential of the individual magnetic particles in terms of their spherical harmonic expansions (SHE). We test this approach on data from scanning superconducting quantum interference device microscopy and microCT of a reference sample. For particles with high signal‐to‐noise ratio of the magnetic scan we demonstrate that SHE up to order n = 3 can be robustly recovered. This additional level of detail restricts the possible internal magnetization structures of the particles and provides valuable rock magnetic information with respect to their stability and reliability as paleomagnetic remanence carriers. Micromagnetic tomography therefore enables a new approach for detailed rock magnetic studies on large ensembles of individual particles.

中文翻译：

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微磁断层扫描的单粒子多极扩展


微磁断层扫描旨在通过将高分辨率磁扫描技术与微 X 射线计算机断层扫描 (microCT) 相结合来重建大量磁性粒子的单独磁化强度。先前的工作证明偶极矩可以被稳健地推断，数学分析表明每个粒子的势场是唯一确定的。在这里，我们描述了一种数学过程，用于根据球谐函数展开（SHE）恢复单个磁性粒子的高阶磁势。我们使用来自扫描超导量子干涉装置显微镜和参考样品的 microCT 的数据测试了这种方法。对于具有高磁扫描信噪比的粒子，我们证明可以稳健地恢复高达n = 3 阶的 SHE。这种额外的细节水平限制了颗粒可能的内部磁化结构，并提供了关于其作为古地磁剩磁载体的稳定性和可靠性的有价值的岩石磁性信息。因此，微磁层析成像技术为对单个颗粒的大型集合进行详细的岩石磁性研究提供了一种新方法。