The protection system of the superconducting coils in the barrel toroid ofATLAS

An analysis of the discharge of the Barrel Toroid under several operating c onditions has been carried out. The main critical parameters of the dischar ge (i.e. the maximum temperature inside the coils, the maximum temperature gradient, the maximum voltage at the coil ends and the maximum decentering forces acting on the BT and ECT magnets) have been calculated for several o perating conditions theaters on, heaters off, short circuit with heaters on or off). The aim of this analysis is to provide a cross check of the protection desi gn of the Barrel Toroid coils [1] with an independent study. The results va lidate the choice to use a low value of dump resistance, and give some impo rtant warning in the case of heater failure or presence of a short circuit.