Houlton J P, Chen M L, Brubaker M D, Bertness K A, Rogers C T
Department of Physics, University of Colorado Boulder, Boulder, Colorado 80309, USA.
National Institute of Standards and Technology, Boulder, Colorado 80305, USA.
Rev Sci Instrum. 2018 Dec;89(12):125107. doi: 10.1063/1.5051667.
We report on the design, construction, and use of axisymmetric magnetic traps for levitating diamagnetic particles. The magnetic traps each consist of two pole pieces passively driven by a neodymium iron boron (NdFeB) permanent magnet. The magnetic field configuration between the pole pieces combined with the earth's gravitational field forms a 3D confining potential capable of levitating a range of diamagnetic substances, e.g., graphite powder, silica microspheres, and gallium nitride (GaN) powder and nanowires. Particles trap stably at atmosphere and in high-vacuum for periods up to weeks with lifetimes largely determined by choices made to actively destabilize the trap. We describe the principles of operation, finite element design, approximate closed-form results for design rules, and examples of operation of such traps.
我们报告了用于悬浮抗磁性粒子的轴对称磁阱的设计、构建和使用。每个磁阱由两个由钕铁硼（NdFeB）永磁体被动驱动的极片组成。极片之间的磁场配置与地球引力场相结合，形成了一个三维约束势，能够悬浮一系列抗磁性物质，例如石墨粉、二氧化硅微球以及氮化镓（GaN）粉末和纳米线。粒子在大气和高真空环境中能稳定捕获长达数周的时间，其寿命在很大程度上取决于为主动破坏捕获而做出的选择。我们描述了此类磁阱的工作原理、有限元设计、设计规则的近似封闭形式结果以及操作示例。
