PARAMETRIC STUDY ON COUPLING LOSS IN SUBSIZE ITER NB3SN CABLED SPECIMEN

The cable in conduit conductors for the various ITER coils are require d to function under pulse conditions and fields up to 13 T. A parametr ic study, restricted to a limited variation of the reference cable lay out, is carried out to clarify the quantitative impact of various cab le parameters on the coupling loss and to find realistic values for th e coupling loss time constants to be used in ac loss computations. The investigations cover ac coupling loss measurements on jacketed sub- a nd full size conductors with variations in type of cabling, twist pitc h, void fraction, and thickness of the chromium coating. The results a re summarised and conclusions regarding the ITER cable design are pres ented. Scaling laws for coupling loss versus void fraction and number of cabling stages are presented.