Effect of Core Width, Placement, and Condition on Calorimetrically Measured AC Loss and Interstrand Contact Resistance of Stainless-Steel-Cored $hbox{Nb}_{3}hbox{Sn}$ Rutherford Cables

摘要

Calorimetric measurements of AC loss were made on $hbox{Nb}_{3}hbox{Sn}$ Rutherford cables furnished with cores of widths 4.5, 5.2, and 10.8 mm in the face-on (FO) and edge-on (EO) orientations of the applied AC field. The resulting FO-measured effective interstrand contact resistances, $R_{perp,eff.}$ , were compared with that of the uncored cable after which it was noted that although the uncored $R_{perp,eff.}$ agreed well with those of previously measured cables, the cored values $-$0.3 to 8 $muOmega$—were lower than expectation. The relatively low $R_{perp,eff.}$ s are attributed to (i) drifting of the narrower cores to one edge of the cable (ii) shrinkage of the effective width of the widest core as a result of severe texturization. After correcting for these deficiencies the projected $R_{perp,eff.}$ for the widest-core cable moved closer to the range of values expected for a full-width-core $hbox{Nb}_{3}hbox{Sn}$ cable.