Critical current of multifilamentary Nb3Sn - insert coil and long sample bend tests

Cabled and monolithic multifilament Nb3Sn conductors have been prepared utilizing various manufacturing approaches. One insert coil and eighteen samples, each approximately two meters in length, have been tested for critical current carrying capability in a background field of 10 T at 4.2 K. The various conductor configurations were evaluated in both the wind-after-react (WAR) and react-after-wind (RAW) conditions. Achievable bend diameters and critical current degradation due to bending are reported as a function of the level of sensitivity for detection of the onset of resistive behavior. Levels of critical current density as high as 10⁵Amperes/cm²(bronze and filament area) were observed. Bend diameters as small as 1.9 cm appear to be achieved in conductors carrying 100 to 300 amperes, depending upon the level of resistivity which can be tolerated for the conductor application. The 4.5 cm I.D. potted react-after-wind coil performed to short sample critical current producing 1 T in the 10 T background field.