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The behavior of YBCO/metal bilayers under transport currents was explored in the framework of fault current limitation (FCL). Properties of the superconducting-normal transition were first studied phenomenologically during sweep current experiments. For current rates higher than 500 A/s, the transition into the normal state was based on non-thermal phenomena and was characterized by a flux creep regime ended by a jump into the normal state. At lower sweep rates, a total diversion of the current in the metallic shunt was observed for temperatures higher than 85K. In this regime, a partial recovery of the superconducting state took place due to a finite thermal resistance between the superconducting and the metallic films. These two properties of partial diversion into the shunt and of fast switching for a quick rise of the current during a default were exploited for current limitation at 77 K. FCL experiments at 50 Hz show that YBCO/Au bilayers limit the current in about 1ms at a value of 2. 5/c by devel
The behavior of YBCO / metal bilayers under transport currents was explored in the framework of fault current limitation (FCL). Properties of the superconducting-normal transition were first studied phenomenologically during sweep current experiments. For current rates higher than 500 A / s, the transition to the normal state was based on a flux creep regime ended by a jump into the normal state. At lower sweep rates, a total diversion of the current in the metallic shunt was observed for temperatures higher than than 85K. In this regime, a partial recovery of the superconducting state took place due to a finite thermal resistance between the superconducting and the metallic films. These two properties of partial diversion into the shunt and of fast switching for a quick rise of the current during a default were exploited for current limitation at 77 K. FCL experiments at 50 Hz show that YBCO / Au bilayers limit the current in about 1ms at a value of 2. 5 / c by devel