Effects of Unequal Inter and Intra-Toroid Response Times on the Quench Performance of the System of Three ATLAS Toroids

The ATLAS Experiment at the LHC (CERN) has a toroidal magnet system composed of one barrel toroid and two end cap toroids powered in series at 20.5 kA with a total stored energy of 1.6 GJ. So far the three magnets have been tested independently. In preparation of the overall magnet system test, here we review the quench behavior under normal and faulty conditions including the information gained from the test of the three single magnets. In particular the consequences of variations in effective quench detection and quench heater activation times are studied. The effects on energy re-distribution, peak temperatures and internal voltage in the three toroids and between the 8 coils within a single toroid are investigated. Based on simulation studies partly verified by experiments, conclusions regarding the quench performance of the entire system are drawn.