Sensitivity of an Energy Doubler Dipole to Beam Induced Quenches

In a series of tests in the Fermilab P-West proton beam an Energy Doubler dipole, model E22-12, was exposed to various intensity 400 GeV/c beams with several types of spills. Results are presented for the sensitivity of this magnet to beam induced quenches. A Monte Carlo beam shower calculation was performed to predict the energy deposition in the coil by the beam and these predictions are compared with quench data. In one case (4.75°K, 3500 A, 15 × 18 mm beam spot), the beam required to induce quenching for microsecond spill was 0.5 to 0.7 × 108 protons per pulse. The Monte Carlo prediction for these conditions is 0.8 × 108 protons per pulse, corresponding to an energy density in the superconductor of 10 mJ cm-3.