Effect of Electropolishing and Low-Temperature Baking on the Superconducting Properties of Large-Grain Niobium
Measurements of superconducting properties such as bulk and surface critical fields and thermal conductivity have been carried out in the temperature range from 2 K to 8 K on large-grain samples of different purity and on a high-purity fine-grain sample, for comparison. The samples were treated by electropolishing and low temperature baking (120° C, 48 h). While the residual resistivity ratio changed by a factor of ~3 among the samples, no significant variation was found in their superconducting properties. The onset field for flux penetration at 2 K, Hffp, measured within a ~30 µm depth from the surface, was ~160 mT, close to the bulk value. The baking effect was mainly to increase the field range up to which a coherent superconducting phase persists on the surface, above the upper critical field.
- Research Organization:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AC05-06OR23177
- OSTI ID:
- 1021423
- Report Number(s):
- JLAB-ACC-10-1246; DOE/OR/23177-1678; TRN: US201117%%88
- Journal Information:
- AIP Conf.Proc., Vol. 1352; Conference: 1st International Symposium, SSTIN10, Newport News, USA, September 22-24, 2010
- Country of Publication:
- United States
- Language:
- English
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