Helium Pressure Increase During a Quench of the Iseult Coil

Abstract

An experimental model has been studied to predict the pressure rise in the Iseult coil during a quench. The model is built of 10 copper equivalent pancake slices and 7 helium channels per pancake. The heat produced by a quench of the Iseult magnet is simulated by electrical heaters put inside each copper plate. Cryogenic pressure and temperature sensors have been fitted in the helium channels and in the bath. The model is cooled by pressurized superfluid helium at 1.8 K. Bath pressure measurements are given for various heating powers and various numbers of heated plates. A scaling law is put forward to extrapolate the model results to the Iseult pressure rise during a quench. Then the hydraulic circuit is numerically simulated to verify the efficiency of the quench valves to limit the pressure to 0.4 MPa.

Human brain MRI at 500 MHz, scientific perspectives and technological challenges

“…Based on these experiments, the safety pressure devices (burst disks and quench valves), were designed with the objective to keep the pressure below 4 bar. Figure 14 presents the results of these calculations in the case of the simultaneous quench of 43 double pancakes (25% of the main coil) [26].…”