Test results of the DPC-TJ: thermal and hydraulic performance☆

Abstract The thermal and hydraulic test results of the DPC-TJ coil, a 24 kA-40 A mm −2 forced-cooled Nb 3 Sn coil, are presented in this paper. The DPC-TJ coil was installed and tested between the DPC-U1 and U2 coils. The weight of the DPC-TJ coil is 2.8 ton and the total cool-down weight of the coil system is 23 ton. It took ≈ 180 h to cool the coils from room temperature to 20 K. The DPC-TJ coil's heat load was 20 W at zero transport current and 40 W at 24 kA, the rated charging state. The pressure drop in the DPC-TJ coil was measured and the obtained value agreed well with that determined by the empirical formula used for the design of the DPC-TJ coil. A.c. losses and inductive losses due to heat input cause a rapid decrease in the helium flow rate at the coil inlet position. This phenomenon was analysed and one of the design standards was derived.