Conduction-cooled ReBCO coils for the wind converter: from laboratory to field test

Abstract

Practical high-current applications of low-temperature superconductors (LTS) include magnetic resonance imaging, nuclear magnetic resonance and large magnet systems for high-energy physics and nuclear fusion. Higher magnetic fields and higher operating temperatures require a changeover to high-temperature superconductors (HTS) such as ReBCO. These ceramic materials have a critical temperature T c above the normal boiling point of nitrogen, which in principle allows them to be cooled by liquid nitrogen instead of liquid helium. Using liquid nitrogen instead of liquid helium can simplify the design of the cooling system for the superconducting application. A disadvantage of such a 'wet' magnet is the limited operating temperature range and the requirement of periodic refills which is problematic in the case of non-continuous supply of the cryogenic liquid. Use of cryocoolers, on the other hand, allows the superconducting magnet to be conduction-cooled also to intermediate temperatures. Gifford-McMahon type crycoolers are most commonly used today due to their relatively low cost and high reliability. The

Predictable and robust performance of a Bi-2223 superconducting coil for compact isochronous cyclotrons

“…Since the heat-capacity of the DP is relatively small, the temperatures during the I c measurements at the lowest temperature are slightly increasing, reducing the critical-currents. Increasing the temperature during an I c measurement will also increase the slope since the transition to the normal state is reached earlier, thereby, lifting the n-indexes [16].…”

Design Study for HybriSCU: A HYBRID NbTi/ReBCO Superconducting Undulator

“…As a result, experimental characterization of every batch would be needed. The available measurement systems to characterize such tapes present limitations depending on the setup like minimum temperature that can be achieved [18], field angle [19], maximum applied field [20] or maximum applied current. For this study, a second-generation tape with advanced pinning from Superpower [16] is considered, which behaves similarly to the tape from Superpower measured by the Robinson Research Institute (in New Zealand) in the high-temperature superconducting wire critical current database [21].…”