EAST中性束注入器稳态偏转磁铁的参数设计与估算研究

中性束注入器偏转磁铁是剥离束流中剩余离子的关键设备,它与剩余离子吞食器等内部部件构成了中性束注入器的束偏转系统。束偏转系统的性能对中性束注入器束流的品质及其束传输效率发挥着重要作用。本文根据EAST(Experimental Advanced Superconducting Tokamak,EAST)中性束注入器对束偏转系统的要求,对其偏转磁铁各性能参数进行了估算。为中性束注入器设计了一台用以剩余离子180°偏转的偏转磁铁。该偏转磁铁采用H型二极电磁铁结构;其磁极端面设计为138cm×47cm的圆角矩形结构;其线圈设计为每侧2饼,每饼2层,每层8根的串联结构,导线选用外方内圆空心铜导体,以满足偏转磁铁稳态运行的需要。该设计的偏转磁铁在370 A励磁电流条件下,可提供80keV氘离子束偏转所需的磁场。实验测试结果显示:500 A励磁电流稳态运行条件下,偏转磁铁线圈冷却水温升约21.5℃,该设计结构的偏转磁铁满足EAST中性束注入器满参数稳态运行和未来运行参数逐步提高的需要。

Parameter design and estimation of deflection magnet for EAST neutral beam injector

The deflection magnet is the key equipment for residual ion separating form the beam passage in neutral beam injector (NBI). The magnet and the ion dump composing the deflection system of neutral beam injector. Performance of beam deflection system plays an important role for beam quality and beam transmission efficiency. According to requirements of deflection system of EAST-NBI, parameters of deflection magnet were estimated. The deflection magnet is designed for residual ion separating with 180 degrees. The H-type two-pole electromagnet structure is employed for deflection magnet. Its design is a rounded rectangle magnetic pole at the dimension of 138cm×47cm. Coil of deflection magnet is designed with two units for each side, each unit has two layers and every layer includes 8 circles. The wire is chosen as quadrate hollow copper conductor, which will meet the needs of steady-state operation of the deflection magnet. The design of the deflection magnet with 370A excitation current will provide a magnetic field to deflect 80keV deuterium ions. Experimental results show: under steady-state operating with 500A excitation current conditions, the temperature rise of cooling water of deflection magnet coil is about 21.5 ℃. The designed deflection magnet can meet the requirement of steady-state operation at full parameters and also fulfill the requirement of operating parameters gradually increase in the future.