The assembly of coated conductors wound spirally on round metal core is one of the most popular types of high-current HTS conductors and is provided commercially as CORC® cable or wire. When quench / thermal runaway occurs in such coated conductors spirally wound on metal core, it is considered that the current sharing by the metal core reduces Joule heating to protect the coated conductors. There are various numerical studies about the quench characteristics of coated conductors wound spirally on metal core, but experimental reports are limited.
We made a sample holder for a short piece of coated conductor spirally wound on metal core (spiral coated conductor, hereafter) which can be installed in our experimental platform for quench experiment of a conduction-cooled sample with various current (up to 500 A), at various temperatures (10 – 70 K), and in various magnetic fields (up to 5 T). The short turn-around time of quench experiments using short samples enables us to study the quench and protection characteristics of spiral coated conductors with various configurations. To induce quench / thermal runaway, a small heater is used to apply localized and transient thermal disturbance on the surface of a sample coated conductor. The voltages of sections on the coated conductor are measured to calculate normal zone propagation velocity. The hot-spot temperature as well as the voltage of the coated conductor and the metal core are measured to estimate the current shared by the metal core. To identify the degradation of the sample by quench, the V-I characteristics of the sample before and after are compared. In order to discuss how the metal core can help protection, experiments are run using samples with / without insulation between coated conductor and metal core. Samples using cores of various materials and diameters will be compared.

Keywords: Coated conductor, Conduction-cooled, Protection, Quench