NbTi/YBCO (yttrium barium copper oxide) composite superconducting wire with circular section

Abstract

The invention discloses an NbTi / YBCO (yttrium barium copper oxide) composite superconducting wire with circular section, belonging to the field of superconducting materials. The composite superconducting wire is characterized in that a low temperature superconducting wire with circular section is covered by a stable layer; the stable layer is covered by a high temperature superconducting substrate layer through rolling; Ag solders are used for soldering the high temperature superconducting substrate layer in the rolled gaps of the high temperature superconducting substrate layer and forming an Ag soldered joint; a high temperature superconductor coating is coated on the outer surface of the high temperature superconducting substrate layer; the low temperature superconducting wire and the stable layer are NbTi / Cu low temperature composite superconducting wires; and the high temperature superconducting substrate layer and the high temperature superconductor coating are respectively madeof Ni-W alloy tapes and high temperature superconducting material YBCO. The composite superconducting wire has the following beneficial effects: a YBCO high temperature superconducting coating conductor and the NbTi / Cu low temperature composite superconducting wires are combined; by utilizing the characteristic that the n value of the YBCO high temperature superconducting material is much less than the n value of the low temperature superconducting material NbTi and the characteristic of high superconductor critical temperature, rise of the whole voltage of the low / high temperature composite superconducting wires can be suppressed and temperature rise of the composite superconducting wire can be reduced; and compared with the traditional low / high temperature superconducting magnets, the superconducting magnet operates more stably, has higher efficiency and is safer, and is applied to high-field MRI (magnetic resonance imaging) magnets, MRI magnets and the like.

Description

technical field [0001] The invention belongs to the field of superconducting materials, in particular to a circular section NbTi / YBCO composite superconducting wire. Background technique [0002] One of the most important properties of a superconductor is that when the temperature drops below the critical temperature T c and the critical magnetic field B c And below, the resistance will suddenly disappear. at the critical temperature T c Below, there is a critical current I c ; When the current passing through the superconductor is greater than the critical current I c , the superconductor will switch to a normal state, that is, a resistive state. In addition, the critical current I c It is a function of temperature T and magnetic field B; with the increase of temperature T or magnetic field B, the critical current I c will become smaller until it disappears and becomes normal. At a certain temperature T, there exists a critical magnetic field B c , when the magneti...

AI Technical Summary

Problems solved by technology

By using high thermal conductivity and high electrical conductivity metals (such as copper, silver, and alloys, etc.) At the same time, when the metal substrate is shunted, Joule heat will be generated

If it cannot be transmitted in time, the temperature of the low-temperature superconductor will rise rapidly, resulting in the quenching of the superconductor.

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