A simple way to obtain true ac losses with a resonant circuit containing a superconductor, using the decay of the circuit current, is described. For the measurement a capacitor is short circuited with a superconducting cable. Energy in the circuit is provided by either charging up the capacitors with a certain voltage, or letting a de flow in the superconductor. When the oscillations are started-either by opening a switch in case a de is flowing or by closing a switch to connect the charged capacitors with the superconductor-the current (via a Rogowski coil) or the voltage on the capacitor can be recorded using, for example, a digital oscilloscope. The amplitude decay of the periodic voltage or current accurately reflects the power loss in the system. It consists of two components-an ohmic purely exponential one (from leads, contacts, etc.), and a nonexponential component originating from the superconductor. The method has been successfully applied for the measurement of the ac loss in a 1 m long superconducting cable model.
|Journal||Superconductor Science & Technology|
|Publication status||Published - 1998|
|Event||1998 Applied Superconductivity Conference - Palm Desert, CA, United States|
Duration: 13 Sep 1998 → 18 Sep 1998
|Conference||1998 Applied Superconductivity Conference|
|City||Palm Desert, CA|
|Period||13/09/1998 → 18/09/1998|