Conveners
M2Po2C - Nb Properties and A15 Conductor
- Xingchen Xu (Fermi National Accelerator Lab)
- Chiara Tarantini (FSU)
We analyze the measured critical current reduction in Nb3Sn Rutherford cables under magnet-relevant transverse pressure levels in terms of the filament strain inside their strands. A mechanical 2D model of cables’ cross-section is developed to translate the stress that is applied to the surface of the impregnated cables into a strain distribution on the surface of its strands. The resulting...
Introducing materials with high specific heat (C) to Nb3Sn composite wires is a promising technique to suppress the intrinsic instability in high-Jc wires and also improve their stability with respect to external perturbations, which might help to reduce the long training of Nb3Sn magnets. Experiments on prototype wires have demonstrated its capability to improve conductor stability in...
In general, practical metallic superconducting wires, such as NbTi, Nb3Sn and V3Ga, have a fine multifilamentary configuration. Its predominant reason would be pointed as the reduction of electromagnetic losses, the improvement of intrinsic and thermal stabilities, and the reduction of mechanical strain. In particular on the A15 compounds, the promotion of the chemical reaction through the...
Tube type Nb3Sn wires are high performance conductors that typically reach a Jc of 2000-2500 A/mm2 at 12 T and 4.2 K (1000-1250 A/mm2 at 15 T). The wires have performance similar to that of PIT conductors, but are simpler, cheaper, and can be drawn down to finer filament sizes. The conductor consists of a number of subelements, each consisting of a...
A clear indicator of purity of niobium (Nb) used for fabricating Superconducting Radio Frequency (SRF) cavities is the Residual Resistivity Ratio (RRR) of the bulk Nb. Usual methods of determining the RRR is by Four-probe resistance measurement techniques. This process is destructive in nature and provides an average value of the RRR of the sample that is being used. It has already been shown...
High Purity large grain niobium ingots produced by CBMM, the global leading producer of niobium, have shown advantages in manufacturing superconducting radio frequency (SRF) cavities for particle accelerators in regard to less expensive fabrication and treatment procedures with comparable or better performance. For this application, the homogeneity of the ingot needs to be ensured. In this...
