We present a planar, scalable magnetic field source, originally conceived for a chip ion trap. It consists of two symmetric sections, each with several independent currents arranged in coplanar, concentric rectangular loops. The currents allow for tuning the strength of the field and its lowest-order derivatives at one discretional position along the source's vertical symmetry axis, a few mm above its surface. We describe the construction and calibration of the device and the cryogenic setup. The two most important current configurations for a Penning ion trap, the homogeneous field and the magnetic bottle, are investigated experimentally. Homogeneous fields around 0.5 T are routinely reached. We discuss the maximum attainable field, and we briefly describe ongoing further developments aiming at homogeneous fields well above 1 T.

中文翻译：

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用于芯片离子阱的平面强磁场源

我们提出了一种平面的、可扩展的磁场源，最初是为芯片离子阱设计的。它由两个对称部分组成，每个部分都有几个独立的电流，它们排列在共面、同心的矩形回路中。电流允许在沿源垂直对称轴的一个任意位置（在其表面上方几毫米处）调整场的强度及其最低阶导数。我们描述了设备的构造和校准以及低温设置。Penning 离子阱的两个最重要的电流配置，均匀场和磁瓶，通过实验进行了研究。通常可以达到 0.5 T 左右的均匀场。我们讨论了最大可达到的场，并简要描述了针对远高于 1 T 的均匀场的正在进行的进一步发展。