Results using active quench protection strip heaters on a reference design D SSC dipole magnet

Measurements were made with a Reference Design D SSC dipole magnet to study the quench behavior of the magnet when active quench protections trip heaters were used to initiate quenches. The magnet has a 2-layer cosine θ coil configuration with a bore diameter of 4 cm and a length of 4.5 m. The strip heaters, their arrangement and installation are described. Three strip heaters individually and in combinations were used during these studies in the first series of which the magnet current was set at that value for which the quantity was maximum. A capacitor was discharged through the strip heater with the charging voltage being increased progressively until a magnet quench was inititated. The time interval between when the voltage was applied to the strip heater and when the magnet quench began was measured as was the time required for the voltage across the magnet coil that had quenched to reach 3V. These times and the quantity are presented for several values of charging voltage for different heaters and combinations of heaters. Curves of these times and as a function of magnet current at constant capacitance and voltage are also shown.