AC losses in tubular superconducting composites with anisotropic surface structure
✍ Scribed by C.N. Carter; J.C. Male; C. Graeme-Barber
- Publisher
- Elsevier Science
- Year
- 1974
- Tongue
- English
- Weight
- 933 KB
- Volume
- 14
- Category
- Article
- ISSN
- 0011-2275
No coin nor oath required. For personal study only.
✦ Synopsis
A C losses have been measured in prototype tubular composite conductors of a design proposed for superconducting ac power transmission lines. The conductors were of 15 and 19 mm diameter, with a niobium surface layer bonded to a copper substrate either directly or via an intermediate layer of niobium-titanium alloy. A t a surface current density appropriate for the working conditions of a power transmission line (40 A mm" I ) the losses measured for current flow in the axial or circumferential directions differed by up to an order of magnitude, depending on details of the surface anisotropy of each sample.
For purely topological anisotropy, manifest in practice as longitudinal corrugations, circumferential currents gave the lower losses. For largely compositional anisotropy, such as longitudinal welds or strips of degraded surface material, circumferential currents gave the greater losses. These results have been interpreted in terms of the surface current distribution in each case.