Testing of the Euratom LCT coil in the toroidal arrangement of the International Fusion Superconducting Magnet Test Facility without external pulsed fields (standard-I) and with them (standard II) and an extended single-coil test

Abstract

k w t r r n n d l n m n u v x h . b mIldI0r.d bv I mnlrrm OI lhl us. 775 tanmnt vda mnar( No IK-*co684w21ux) -. h. us. OOrmmntmtmm.-. h. WUbd fm d rm cmabumn. 0. . l m o h m do so. AbstractTesting of the European LCT coil, a forced-flow NbTi coil, with the five other coils in the International Fusion Superconducting Magnet Test Facility (IFSMTF) has been in progress since the beginning of 1986. By the end of July 1987, the Euratom-LCT coil had passed a single-coil test, a test in toroidal configuration with and without poloidal field transients, and an extended single-coil test up to its design limits. In this test, the coil reached, in stable operation, a field of 9 T at 140% of rated current. It reached the short-sample values of the strands used in the cable. The coil was operated up to 8 T with and without poloidal field transients in a toroidal configuration. The mass flow rate was reduced by a factor of 5 compared with the design value without any visible impact on stability. Averaged ac losses (winding, 14 W; case, 7 W) were measured under LCT specified poloidal field pulses, and the findings agreed with those of the short-sample measurements. The mechanical properties behaved as predicted by calculations. No global movement of the winding in the coil case was found, although the coil has already experienced 50% (14 MN) of the maximum out-of-plane force. The operating limits were determined by measuring the current-sharing temperature. It was found that the helium mass flow rate had an impact on the hot-spot temperature of a normal region. All results obtained demonstrate that the applied technology has achieved reliable engineering standards.