Orateur
Description
"To improve the current density and mechanical strength of insulated REBCO magnets, thin, stiff and strong insulation is very beneficial. An innovative insulation solution, using an Hastelloy C276 tape coated with an insulating MgO layer, has been studied. As a high operating current is generally also beneficial for magnet protection, co-winding of several REBCO tapes is also interesting but can lead to significant coupling or magnetisation losses. Prototype pancakes with two co-wound REBCO tapes and an MgO insulated tape have been manufactured.
The mechanical and current carrying capability of these prototypes have been tested in background field at 4.2 K. The pancakes have also been tested in self-field with sinusoidal current at 77 K to measure AC losses and to check the ability to withstand the turn-to-turn voltage. The test protocols and results are presented.
Electro-magnetic simulations of the prototype were performed to understand the experimental behaviour and analyse the measured signals. It gives insights on the relative contributions of the different loss mechanisms depending on the operating current and frequency."