Fabrication and Test of Diameter 35 mm Iron-Based Superconductor Coils

Iron-based superconductor (IBS) is expected to be the next generation high temperature superconductor with their potential good properties for the high-field application. This study focus on exploration of the characteristics of IBS coils at high field and development of the IBS coil fabrication technology. A series of diameter 35 mm IBS coils including single pancake (SPC) and double pancakes (DPC) were designed and winded with the 7-filamentary Ba
_1-x
K
_x
Fe
₂
As
₂
(Ba122) tape which was produced by the Institute of Electrical Engineering, Chinese Academy of Sciences (IEE-CAS). The IBS coils were divided into 3 groups according to the different fabrication processes. The tests of the IBS coils were firstly carried out at 4.2 K and 10 T background field. The highest quench current of the coils at 10 T is 69.4 A, which is about 90% of the critical current of the short sample at 10 T. Then, two SPCs were selected and tested at 4.2 K at 24 T [1]. The highest quench current of the coils at 24 T is 25.6 A, which is about 39% of the quench current at self-field. The test results were presented and analyzed with respect to the different fabrication processes.