The concept of a high-gradient trapped field magnet (HG-TFM), which incorporates a hybrid system of two (RE)BaCuO superconducting bulk components with different functions, was proposed in 2021 by the authors based on the results of numerical simulations. The HG-TFM as a desktop-type magnet can be a more effective way to generate a higher magnetic field gradient product of B_z · dB_z /dz (>−1400 T² m⁻¹, as calculated for a pure water), which can realize a quasi-microgravity space applicable for Space Environment Utilization on a laboratory scale. In this study, to validate the quasi-microgravity space in the HG-TFM, a prototype HG-TFM apparatus has been built using a slit-bulk TFM and stacked full-TFM (without slits) with inner diameters of 36 mm. After field-cooled magnetization from 8.60 T at 21 K, a trapped field of B _T = 8.57 T was achieved at the center (i.e. at the bottom of a room temperature bore of 25 mm diameter outside the vacuum chamber), and consequently, a maximum B_z · dB_z /dz = −1930 T² m⁻¹ was obtained at the intermediate position between the slit-bulk TFM and the stacked full-TFM. Magnetic levitation was demonstrated successfully for bismuth particles and a pure water drop, which validates the quasi-microgravity environment in the HG-TFM. Based on numerical simulation results of the trapped field profile, it is concluded that the reason for the instability of the levitated targets is because of the repulsive magnetic force applied along the horizontal plane. The levitating state can be controllable, for example, by changing the operating temperature, which would allow objects to levitate statically along the central axis.

中文翻译：

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验证在高梯度俘获场磁体 (HG-TFM) 的室温孔中提供准微重力空间的台式磁体

作者于 2021 年根据数值模拟的结果提出了高梯度俘获场磁体 (HG-TFM) 的概念，该概念结合了两个具有不同功能的 (RE)BaCuO 超导块状元件的混合系统。HG-TFM 作为台式磁铁可以更有效地产生更高的磁场梯度积z _{_} ·z _{_} /dz(>-1400 T ² m ^-1，按纯水计算)，可实现实验室规模适用于空间环境利用的准微重力空间。在这项研究中，为了验证 HG-TFM 中的准微重力空间，使用内径为 36 mm 的狭缝体 TFM 和堆叠式全 TFM（无狭缝）构建了原型 HG-TFM 设备。在 21 K 下从 8.60 T 场冷却磁化后，捕获场乙 _T = 8.57 T 在中心实现（即在真空室外直径为 25 mm 的室温孔的底部），因此，最大值z _{_} ·z _{_} /dz= −1930 T ² m ⁻¹是在狭缝体 TFM 和堆叠式全 TFM 之间的中间位置获得的。成功地证明了铋颗粒和纯水滴的磁悬浮，这验证了 HG-TFM 中的准微重力环境。基于俘获场剖面的数值模拟结果，可以得出结论，悬浮目标不稳定的原因是由于沿水平面施加的排斥磁力。悬浮状态是可控的，例如，通过改变工作温度，这将允许物体沿中心轴静态悬浮。