IPAC'24 - 15th International Particle Accelerator Conference

Solder joint cryogenic fatigue of the RHIC 12x150A current leads and mitigation for future operation

TUPR56

21 May 2024, 16:00

2h

Rock 'n Roll (MCC Exhibit Hall A)

Poster Presentation MC7.T13 Cryogenics Tuesday Poster Session

Speaker

Frederic Micolon (Brookhaven National Laboratory (BNL))

Description

A failure of the RHIC powering system occurred at the end of run 23 and led to the discovery of ruptured con-ductors on the 12x150A current leads used to feed cur-rent to the superconducting (SC) magnet circuits. These ruptured conductors are thought to have led to an electri-cal breakdown, first within the solder joint, and then across adjacent conductors of the same current lead assembly. A fatigue experiment has been set up to study the behavior of Sn96Ag4 solder joints under cycling load at cryogenic temperature. Mitigation measures to mini-mize further fatigue cycling have been implemented for the next RHIC run and will be discussed. This paper aims to describe our understanding of the solder joint cracking issue encountered and present the mitigation measures for future RHIC operation.

Funding Agency

Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.