GB1179740A - Superconducting Magnet Apparatus - Google Patents

Abstract

1,179,740. Superconductor magnets. HITACHI Ltd. 16 June, 1967 [22 June, 1966], No. 27836/67. Heading H1P. A super-conductor coil comprises a plurality of sections each of which is supplied with a current less than its critical current in the magnetic field to which it is subjected. In an embodiment, each of the legs 11 of a pair of saddle shaped coils, Fig. 4, is constructed of three sections, the innermost section carrying the least current and the outermost section carrying the most current since they are subjected respectively to the highest and lowest magnetic fields. The three sections are connected in series to a single power supply, the currents through the middle and inner sections being reduced by by-passing some of the current through variable resistors. Fig. 10 (not shown). The legs of the coils can be wound to an arcuate cross-section. Fig. 7 (not shown), to reduce the size of the coil. Other ways of subdividing the legs and the bridging sections (12) are described, Figs. 6 and 8 (not shown). Circuits for supplying a large number of winding sections with different currents are also described. Figs. 13 and 14 (not shown). Each of the coil sections may be bridged by a super-conductor switch so that when the required currents have been established, the coil can be switched to the persistent current mode, Fig. 15 (not shown). The superconductor wire may comprise four Nb-Zr filaments embedded in a copper strip, Fig. 1 (not shown), and consecutive winding layers are separated from each other by copper spacers (23) having apertures (24) for the cooling liquid, Figs. 7 and 8 (not shown). Other forms of super-conductor wire. Figs. 2 and 3 (not shown), and other materials are also described.