TY - JOUR A1 - Li, Shisong A1 - Stock, Michael A1 - Schlamminger, Stephan T1 - A new magnet design for future Kibble balances JF - Metrologia N2 - We propose a new permanent magnet system for Kibble balance experiments, which combines advantages of the magnet designs invented by the National Physical Laboratory (NPL) and by the Bureau International des Poids et Mesures (BIPM). The goal of the proposed magnet system is to minimize the coil-current effect and to optimize the shielding at the same time. In the proposed design, a permanent magnet system with two gaps, each housing a coil, is employed to minimize the coil current effect, by reducing the linear coil-current dependence reported for the single air gap design by at least one order of magnitude. Both air gaps of the magnet are completely surrounded by high-permeability material, and hence the coils are shielded from outside magnetic fields and no magnetic field leaks outside of the magnet system. An example of the new magnet system is given and the analysis shows that the magnetic field in the air gap can be optimized to meet the requirement to be used in Kibble balances. KW - II WATT BALANCE KW - inductance force KW - JOULE BALANCE KW - Kibble balance KW - magnetic field KW - magnetic shielding KW - MARK-II KW - NATIONAL INSTITUTE KW - NIM KW - PLANCK CONSTANT KW - standards KW - SYSTEM KW - TECHNOLOGY Y1 - 2018 U6 - https://doi.org/10.1088/1681-7575/aab2ea VL - 55 IS - 3 SP - 319 EP - 325 PB - IOP PUBLISHING ER -