Coil bobbin composed of high strength polyethylene fiber reinforced plastics for a stable high field superconducting magnet

摘要

High field superconducting solenoid magnets sometimes quench by wire motion induced by electro-magnetic force. High strength polyethylene fiber reinforced plastic (DFRP) has a negative thermal expansion coefficient and a low frictional coefficient. DFRP pipes made by filament winding method could be constructed so as to expand in the circumferential direction when cooled to low temperature with an appropriate selection of winding angle and shape of the pipes. In the case of a superconducting coil wound on a DFRP bobbin, it is expected that wire motions in high field are decreased by expansion of the coil bobbin. In this work, sample coils wound on DFRP bobbin and stainless steel (SUS) bobbin were prepared. The sample coil voltages were measured during increasing current in background external field. The coil using SUS bobbin showed many sharp peaks in tap voltage induced by quick wire motions. In contrast, those using DFRP bobbin showed no peaks. These results suggest that the quick wire motions were constrained by DFRP bobbin which had a negative thermal expansion coefficient and a low frictional coefficient. (C) 2002 Published by Elsevier Science B.V. [References: 10]