Comparing with conventional insulated high temperature superconducting (HTS) coil, the no-insulation (NI) one has advantages of high stability, self-protection and fast quench recovery. However, the unstable and non-uniform magnetic field appear in NI coil during exciting owing to too low transverse resistivity among turns. This paper proposed a method for increasing stability and decreasing screen current by enhancing transverse resistivity among turns of no-insulated HTS coil which was fabricated by co-winding REBCO and stainless steel (SS) tapes. The latter tape functioned as increasing mechanical strength and protection of NI HTS coil. In order to enhance the transverse resistivity, the SS tape was thermally and chemically treated. Two NI HTS coils co-wound with treated and non-treated SS tapes were designed and fabricated. Both of them are analyzed and tested, the results show that the NI HTS coil with co-wound by treated SS tape has lower screening current and coupling losses as well as higher temporal stability than that one co-wound by non-treated SS tape.
Key words: non-insulation coil; temporal stability; transverse resistivity, treatment