Abstract: In a method of manufacturing a copper clad aluminum channel superconductive conductor, an electrically conductive wire comprising a metal or alloy core is formed with a longitudinally extending groove in a surface thereof. A wire made of a material that exhibits superconducting properties within a defined temperature range is soldered into the groove.

Abstract: A suspension assembly for mechanically retaining a first article by bracing it against a second article includes a spherical or spheroid object located between first and second articles. A first set of at least three rounded surfaces is mechanically braced between the spherical or spheroid object and the first article, with each of such surfaces being in contact with the spheroid object at a single point; and a second set of at least three rounded surfaces mechanically is braced between the spherical or spheroid object and the second article, with each of said surfaces being in contact with the spherical or spheroid object at a single point.

Abstract: A suspension assembly for mechanically retaining a first article by bracing it against a distant second article, includes a tensile rod that extends between first and second articles. At least one first surface is mechanically linked to the tensile rod, and at least one second surface mechanically linked to the first article. The first surface and said second surface are braced against one another by tension in the tensile rod, and have at least three separate points of contact between them. At least one of the first and second surfaces is non-planar, and at least one of the points of contact is provided by a part of the surface which is convex and non-planar.

Abstract: A cryogenic refrigerator comprising a rotary valve which controls the flow of high pressure gas into the refrigerator and the return of the gas from the refrigerator, the cryogenic refrigerator further comprising rotary fluid motor arranged to drive the rotary valve.