Abstract
RE-Ba-Cu-O (REBCO, where RE denotes rare earth elements) superconductor tapes are prone to uncontrolled quench damage especially because of the tape architecture which consists of a monolithic, 2–5-μm-thick film. Moreover, commercial REBCO tapes are not very uniform; defective regions are susceptible to become hot spots when currents of several hundred amperes are transported through the very thin films. In this work, we have been developing new REBCO tape architectures such as double sided tapes where REBCO films are deposited on both sides of the tape, and slot-and-fill (Slot-n-Fill) where slots are created in the insulating buffer stack and filled with a conductive material to shunt current to the substrate. These architectures have been shown to promote current sharing by lowering the contact resistivity between tape strands. The primary objective of this work is to evaluate the quench characteristics of these defect-tolerant REBCO tape architectures. The different architectures result in different thermal conductivity and resistivity at normal state, which cause different quench characteristics, such as minimum quench energy (MQE), normal zone propagation velocity (NZPV), and hotspot temperature. In this work, the minimum quench energy and quench propagation behavior of tapes with different architectures, as well as coils fabricated from these tapes, are measured. The quench stability measurement was conducted at 77 K in nitrogen vapor.