A thermal-insulated multi-walled pipe for superconducting power transmission comprises: a superconducting cable; a multi-walled pipe composed of a plurality of straight pipes and houses the superconducting cable; and a plurality of spacers that are located between adjacent two straight pipes of the plurality of straight pipes, wherein a cross-sectional shape of each spacer is a polygon having three or more vertices, each spacer has a through-hole at a center in the plane, an inner straight pipe is located to pass through the through-hole, a frictional coefficient .sub.i between each spacer and the inner straight pipe is 0.1 or less, a frictional coefficient .sub.o between each spacer and an outer straight pipe is 0.1 or less, and a ratio L.sub.d/d of a diagonal equivalent length L.sub.d of the polygon to an inner diameter d of the outer straight pipe of the adjacent two straight pipes is 0.9 or less.

Provided is a thermal-insulated multi-walled pipe for superconducting power transmission that highly prevents intrusion of external heat due to radiation and has excellent thermal insulation property without using a superinsulation. A thermal-insulated multi-walled pipe for superconducting power transmission comprises: a superconducting cable; and a multi-walled pipe that houses the superconducting cable, wherein the multi-walled pipe is composed of a plurality of straight pipes, and at least one of the plurality of straight pipes has, at a surface thereof, a zinc or zinc alloy-plated layer having an average spangle size of 2.0 mm or less.

Provided is a thermal-insulated multi-walled pipe for superconducting power transmission that highly prevents intrusion of external heat due to radiation and has excellent thermal insulation property without using a superinsulation and can be produced easily. A thermal-insulated multi-walled pipe for superconducting power transmission comprises: a superconducting cable; and a multi-walled pipe that houses the superconducting cable, wherein the multi-walled pipe is composed of a plurality of straight pipes, and at least one of the plurality of straight pipes has, at a surface thereof, a coating layer containing a metal powder.

Provided is a thermal-insulated multi-walled pipe for superconducting power transmission that highly prevents intrusion of external heat due to radiation and has excellent thermal insulation property without using a superinsulation and can be produced easily. A thermal-insulated multi-walled pipe for superconducting power transmission comprises: a superconducting cable; and a multi-walled pipe that houses the superconducting cable, wherein the multi-walled pipe is composed of a plurality of straight pipes, and at least one of the plurality of straight pipes has, at a surface thereof, a coating layer containing a metal powder.

A superconductive cable including: a former; one or more superconductive conductor layers provided outside the former; an insulating layer configured to surround the superconductive conductor layers; and one or more superconductive shield layers provided on an exterior of the insulating layer. The superconductive conductor layers and the superconductive shield layers are formed of superconductive wire rods, and each superconductive wire rod includes a metal substrate layer and a plurality of superconducting layers deposited on the metal substrate layer using a superconductive material. In the superconductive wire rods of an outermost superconductive conductor layer among the superconductive conductor layers and an innermost superconductive shield layer among the superconductive shield layers, each of the metal substrate layers and the superconducting layers are disposed in opposite directions.

A superconductive cable including: a former; one or more superconductive conductor layers provided outside the former; an insulating layer configured to surround the superconductive conductor layers; and one or more superconductive shield layers provided on an exterior of the insulating layer. The superconductive conductor layers and the superconductive shield layers are formed of superconductive wire rods, and each superconductive wire rod includes a metal substrate layer and a plurality of superconducting layers deposited on the metal substrate layer using a superconductive material. In the superconductive wire rods of an outermost superconductive conductor layer among the superconductive conductor layers and an innermost superconductive shield layer among the superconductive shield layers, each of the metal substrate layers and the superconducting layers are disposed in opposite directions.

The various embodiments described herein include methods, devices, and systems for fabricating and operating superconducting circuits. In one aspect, an electric circuit includes: (1) a first superconducting component having a first terminal, a second terminal, and a constriction region between the first terminal and the second terminal; (2) a second superconducting component having a third terminal and a fourth terminal; and (3) a first electrically-insulating component that thermally couples the first superconducting component and the second superconducting component such that heat produced at the constriction region is transferred through the first component to the second superconducting component.

The various embodiments described herein include methods, devices, and systems for fabricating and operating superconducting circuits. In one aspect, an electric circuit includes: (1) a first superconducting component having a first terminal, a second terminal, and a constriction region between the first terminal and the second terminal; (2) a second superconducting component having a third terminal and a fourth terminal; and (3) a first electrically-insulating component that thermally couples the first superconducting component and the second superconducting component such that heat produced at the constriction region is transferred through the first component to the second superconducting component.

A superconductive cable including: a former; one or more superconductive conductor layers provided outside the former; an insulating layer configured to surround the superconductive conductor layers; and one or more superconductive shield layers provided on an exterior of the insulating layer. The superconductive conductor layers and the superconductive shield layers are formed of superconductive wire rods, and each superconductive wire rod includes a metal substrate layer and a plurality of superconducting layers deposited on the metal substrate layer using a superconductive material. In the superconductive wire rods of an outermost superconductive conductor layer among the superconductive conductor layers and an innermost superconductive shield layer among the superconductive shield layers, each of the metal substrate layers and the superconducting layers are disposed in opposite directions.

A superconductive cable including: a former; one or more superconductive conductor layers provided outside the former; an insulating layer configured to surround the superconductive conductor layers; and one or more superconductive shield layers provided on an exterior of the insulating layer. The superconductive conductor layers and the superconductive shield layers are formed of superconductive wire rods, and each superconductive wire rod includes a metal substrate layer and a plurality of superconducting layers deposited on the metal substrate layer using a superconductive material. In the superconductive wire rods of an outermost superconductive conductor layer among the superconductive conductor layers and an innermost superconductive shield layer among the superconductive shield layers, each of the metal substrate layers and the superconducting layers are disposed in opposite directions.