June 28, 2015 to July 2, 2015
JW Marriott Starr Pass Resort
Etc/GMT-7 timezone

Performance of the cold powered diodes and diode leads in the main magnets of the LHC

Jun 30, 2015, 4:30 PM
Tucson Ballroom F

Tucson Ballroom F

Contributed Oral Presentation CEC-06 - Superconducting Magnet Systems C2OrF - Superconducting Magnets II


Dr Gerard Willering (CERN)


During quench tests in 2010 variations in resistance of an order of magnitude were found in the diode by-pass circuit of main LHC magnets. An investigation campaign was started to understand the source, the occurrence and the impact of the high resistances. Many tests were performed offline in the SM18 test facility with a focus on the contact resistance of the diode to heat sink contact and the diode wafer temperature. In 2014 the performance of the diodes and diode leads of the main dipole bypass systems in the LHC was assessed during the so-called CSCM test. In the test a current cycle similar to a magnet circuit discharge from 11 kA with a time constant of 100 s is performed. Resistances of up to 400 µΩ have been found in the diode leads at intermediate current, but in general the high resistances decrease at higher current levels and no signs of overheating of diodes have been seen and the bypass circuit passed the test. In this report the performance of the diodes and in particular the contact resistances in the diode lead are analysed with available data acquired over more than 10 years from acceptance test until the CSCM test in the LHC.

Primary author


Presentation materials