标题： 基于磁悬浮的低重力模拟器具有前所未有的大功能体积 显示英文标题

标题： A magnetic levitation based low-gravity simulator with an unprecedented large functional volume

摘要： 低重力环境可能对生物系统的行为、流体的动力学和传热以及材料的生长和自组织产生深远的影响。 对重力影响的系统性研究对于推进我们的知识和确保太空任务的成功至关重要。 由于典型太空飞行任务中成本高昂以及有效载荷尺寸和质量的限制，基于地面的低重力模拟器已成为准备太空实验和作为独立研究平台不可或缺的工具。 在各种模拟器系统中，基于磁悬浮的模拟器（MLS）由于其易于调节的重力和实际无限的操作时间而一直受到广泛关注。 然而，MLS的一个公认问题是其高度不均匀的力场。 对于一个螺线管 MLS，功能体积$V_{1\%}$，其中净力产生的加速度小于地球重力的 1%$g$，通常为几微升（$\mu L$）或更小。 在本工作中，我们报告了一种创新的 MLS 设计，该设计结合了超导磁体和梯度场 Maxwell 线圈。 通过优化分析，我们表明，在直径为 8 厘米的紧凑线圈中可以实现前所未有的$V_{1\%}$超过 4,000$\mu L$。 我们还讨论了如何使用现有的高$T_c$超导材料来制造这样的 MLS。 当此 MLS 中的电流减少以模拟火星上的重力（$g_M=0.38g$），其中重力在$g_M$的几个百分比范围内的功能体积可能超过 20,000$\mu L$。 我们的设计可能为各种令人兴奋的未来低重力研究开辟新领域。 显示英文摘要

摘要： Low gravity environment can have a profound impact on the behaviors of biological systems, the dynamics and heat transfer of fluids, and the growth and self-organization of materials. Systematic research on the effects of gravity is crucial for advancing our knowledge and for the success of space missions. Due to the high cost and the limitations in the payload size and mass in typical spaceflight missions, ground-based low-gravity simulators have become indispensable for preparing spaceflight experiments and for serving as stand-alone research platforms. Among various simulator systems, the magnetic levitation based simulator (MLS) has received long-lasting interests due to its easily adjustable gravity and practically unlimited operation time. However, a recognized issue with MLSs is their highly non-uniform force field. For a solenoid MLS, the functional volume $V_{1\%}$, where the net force results in an acceleration less than 1\% of the Earth's gravity $g$, is typically a few microliters ($\mu L$) or less. In this work, we report an innovative MLS design that integrates a superconducting magnet with a gradient-field Maxwell coil. Through an optimization analysis, we show that an unprecedented $V_{1\%}$ of over 4,000 $\mu L$ can be achieved in a compact coil with a diameter of 8 cm. We also discuss how such an MLS can be made using existing high-$T_c$ superconducting materials. When the current in this MLS is reduced to emulate the gravity on Mars ($g_M=0.38g$), a functional volume where the gravity varies within a few percent of $g_M$ can exceed 20,000 $\mu L$. Our design may break new ground for various exciting future low-gravity research.