Experimental Analysis and Modeling of the Electrical and Thermal Transients of the Diode-By-pass for the LHC- Magnet Protection at Cryogenic Temperatures

For the protection of the LHC superconducting lattice magnets cold bypass diodes will be installed inside the magnet cryostat, subjecting them to superfluid helium temperatures and radiation. During a magnet quench, the power generated in the diode must be dissipated in the adjacent heat sinks of copper that are part of the diode package. Results from endurance tests on the diode package are presented. A simple thermo-electric model has been developed to simulate the thermal and electrical transients in the diode package during the endurance pulse. Simulation results are in good agreement with the measured temperatures.