Author :
Kizu, K. ; Tsuchiya, K. ; Shimada, K. ; Ando, T. ; Hishinuma, Y. ; Koizumi, N. ; Matsukawa, M. ; Miura, Y.M. ; Nishimura, A. ; Okuno, K. ; Seo, K. ; Takahata, K. ; Tamai, H. ; Yamada, S.
Abstract :
Effects of tensile and compressive strain on critical currents (I c) of Nb3Al strand and cable-in-conduit (CIC) conductor were investigated using a newly developed apparatus. The Nb 3Al strand manufactured by jelly roll process was 0.74 mm in diameter with a copper/noncopper ratio of 4.05. The CIC conductor sample which consists of two Nb3Al strands and one copper wire inserted into a stainless steel conduit was prepared. The effective strain and magnetic field ranges for the CIC conductor sample were from -0.91% to +0.26% and from 6 T to 11 T, respectively. It is clearly shown that the Ic decrease of the CIC conductor sample by longitudinal strain is relieved considerably compared with the strand sample, indicating the relaxation of intrinsic strain in Nb3Al filaments in CIC conductor due to the cabling effect. The relaxation effect is about +0.1% for -0.8% in effective strain of CIC conductor
Keywords :
aluminium alloys; compressibility; critical currents; fusion reactor materials; niobium alloys; stress relaxation; superconducting coils; tensile strength; 0.74 mm; 6 to 11 T; Nb3Al; cable-in-conduit conductor; cabling effect; compressive strain effects; copper wire; critical currents; effective strain; filaments; fusion reactors; intrinsic strain relaxation effect; jelly roll process; longitudinal strain; magnetic field; stainless steel conduit; strands; superconducting coils; tensile effects; Capacitive sensors; Conductors; Copper; Critical current; Image coding; Magnetic field induced strain; Manufacturing processes; Niobium; Tensile strain; Wire; Cable-in-conduit conductor; critical current; strain;