The presence of defects in REBCO coated conductors (hereafter CCs) causes a low of I_c. Since the number of defects in recent CCs has gradually been reduced[1], the probability that the defects in two tapes locate at the same position should be rare. Therefore, the FFDS (face to face double stacked) CC in which two CCs are stacked can avoid a serious decrease of I_c due to defects [2]. It is assumed that stacked two CCs has better bending characteristics than single CCs because the position of the neutral line with respect to bending is close to the REBCO layer, but there have been no systematic reports so far. Therefore, we obtained the change of I_c by I-V measurement for different radius of curvature from 25 mm to 7.5 mm of FFDS CCs. As a result, the rate of decrease of I_c was only about 1% even when bent to R7.5 mm. In the presentation, we will also discuss the stress-strain curve and the bending characteristics when two FFDS CCs are connected.

This work is supported by NEDO.

References
[1] T. Machi, et al., ‘Improvement of uniformity of filamentary Ic on scribed coated conductors’, 1st Asian ICMC and CSSJ 50^th (2016).
[2] Takanobu Kiss, et al., ‘Analysis and Modeling of Current Transport Properties in Long Length Coated Conductors‘, ISS2017

Keywords: Coated Conductors, FFDS, Bending characteristics