The main purpose of this work was to design, develop and construct a simple, low-cost AC susceptometer to measure large, bulk superconducting samples (up to 32 mm in diameter) in the temperature range 78-120 K. The design incorporates a double heating system that enables a high heating rate (25 K/hour) while maintaining a small temperature gradient (< 0.2 K) across the sample. The apparatus can be calibrated precisely using a copper coil connected in series with the primary coil. The system has been used successfully to measure the temperature dependence of the AC magnetic properties of entire RE-Ba-Cu-O [(RE)BCO] bulk superconducting domains. A typical AC susceptibility measurement run from 78 K to 95 K takes about 2 hours, with excellent temperature resolution (temperature step ~ 4 mK) around the critical temperature, in particular.
@article{arxiv.0805.1285,
title = {An AC susceptometer for the characterization of large, bulk superconducting samples},
author = {P Laurent and J F Fagnard and B Vanderheyden and N Hari Babu and D A Cardwell and M Ausloos and P Vanderbemden},
journal= {arXiv preprint arXiv:0805.1285},
year = {2009}
}
Comments
25 pages, 7 figures. Accepted for publication in Measurement Science and Technology