Binary Nitrogen-Cooled 10 kA Leads

Abstract

A pair of binary current leads has been constructed with a nitrogen vapor cooled resistive section and a stainless steel shunted HTS lower section. These leads are intended as replacement leads for the NHMFL 45 T Hybrid and also serve as half-current prototypes for the 20 kA leads foreseen for the Series Connected Hybrids that are under development at the NHMFL. An amount of liquid nitrogen is maintained in a reservoir at the bottom of the resistive section such that vapor flow is determined by selfdemand. The liquid nitrogen delivery system and properties of the vapor cooled section of the leads are described. A comparison is made between the measured and calculated properties of the resistive section in steady state and transient conditions.

The design of YBCO binary current leads and its electromagnetic-thermal coupling analysis based on PEEC and finite volume method

“…HTS binary current leads were first proposed by Mumford in 1989 [3]. In the past few years, HTS binary current leads have been widely applied, not only in large-scale systems, such as particle accelerators [4][5][6][7] and fusion devices [8][9][10][11][12][13], but also for smaller isolated magnets, such as superconducting magnetic resonance imaging (MRI) magnets [14,15], high-field magnet system [16][17][18][19][20][21] and other special test facilities [22][23][24][25][26][27][28][29][30]. The typical structure of binary current leads comprises two parts: a hightemperature portion made by a normal conductor and a lowtemperature portion made by an HTS and a normal metal shunt.…”

Development of a high-temperature superconducting bus conductor with large current capacity

“…With advances in the production technology of HTS tapes, several HTS cables of various powers have been built [1][2][3][4][5][6]. To our knowledge, there have been few HTS cable demonstrations with a current capacity of 10 kA and above, operating at liquid nitrogen temperature (77 K), except for several HTS current leads operating in the range of 77 and 4.2 K applicable for superconducting devices such as SMES, particle accelerators such as Tevatron, HERA, RHIC and LHC, experimental test instruments for nuclear fusion reactors such as ToreSupra, TRIAM, LHD, EAST, KSTAR, W7-X, JT-60SA and ITER, etc [7][8][9][10][11][12].…”