An evaluation of the inlet flow reduction for a cable-in-conduit conductorin pulsed operation

The cable-in-conduit conductor (CICC) is applied for large devices, such as the fusion magnets, because it has a high mechanical and electrical perfor mance potential. Also, CICC has advantages when applied for pulsed operatio n coils, such as the fusion mag nets and superconducting magnetic energy st orage coils, because of its thermal and hydraulic performance. Superconduct ing coils made from CICC have a cooling path and the coolant of the supercr itical helium circulates through the inside of the CICC. When the coil has heat generation due to the AC losses, the CICC has the advantage of being a ble to remove heat due to the large wet perimeter. The inlet flow reduction is caused by the heat generation of the conductor. The inlet flow reductio n provides a limit to the stable pulsed operation of the coil. The inlet fl ow reduction is measured and discussed for the CICC in this paper. The desi gn criteria of the inlet flow reduction is introduced for the CICC. The zer o flow temperature is defined to achieve this purpose. The initial flow rat e can be estimated by this criteria, which is applicable for the forced flo w conductor, as well as for CICC. (C) 1998 Elsevier Science Ltd. All rights reserved.