HTS coil test facility in a large bore 20 T resistive magnet at LNCMI

The high temperature superconductor (HTS) coil development, especially in the interest of high field insert coil, requires characterizations of a prototype coil in high magnetic field. Our test probe fits into the bore of ø 170 mm 20 T dc magnet, and the sample space ø 130 mm allows test coils with ∼ø 110 mm and 140 mm height. A fast data acquisition method at sampling period of 0.1 ms was developed for coil quench test program, and a working principle of the method is demonstrated for a small test coil. To accommodate high current required in tests such as I_c and hoop stress tests, the new current leads were manufactured with an optimal current measured in the range of 600 ∼ 700 A, which was sufficient for the envisaged coil tests. For short duration, the current lead could carry more than 1000 A without any influence of overheating in short sample I_c test. A demonstration of short sample I_c test is also presented.