BSCCO-2223 wire

The most widely used development in HTS wire production is tlie powder-in-tube procedure with BSCCO ceramic materials. In this procedure very fine HTS powder, placed inside of a hollow silver tube, is fused as the tube lengtn is mechanically increased to form a wire. Very high magnetic fields with this wire have been reported at 4 K however, the performance degrades substantially above 20 to 30 K. 

Why is the BSCCO superconductor the material of choice for superconducting wires ... 

Critical current densities on the order of 10 A cm at 77 K in zero field were measured on BSCCO thin films. In Fig. 4.2-46 the field dependence of 7c of a B12212 film is shown for two temperatures [2.90] and Fig.4.2-47 demonstrates the Jc(B, T) dependence of a B12223 film [2.87]. In magnetic fields aligned parallel to the plane of the film, that is perpendicular to the c axis of the crystal structure, 7c is practically independent on the field strength, even at higher temperatures such as 60 K. The reasons for this behavior are discussed below in connection with the Jc(B, T) correlation of wires and tapes. 

Shown in fig. 16 is the magnetic field dependence of the critical current density for the IBAD and RABiTS based YBCO coated samples recently produced at LANL and ORNL, respectively. These coated samples operated in the liquid nitrogen temperature range clearly outperform the metallic superconductors (NbTi, NbjSn) at 4.2 K. Furthermore, even in the worst field direction H c), and for temperatures below 65 K, the short sample YBCO coated conductors operated in a 8-tesla background field have at least an order of magnitude higher Jc than pre-commercial BSCCO-2223 wire with no applied field. 

Fig. 16. Magnetic field dependence of the critical current density for a range of short sample YBCO conductors produced using either IBAD or RABiT substrates. These data are compared with typical values obtained for NbTi and Nb3Sn wires at 4.2 K and for BSCCO, oxide-powder-in-tube wires at 77 K. From Hawsqr and Peterson (1996).

Superconducting wires were first made from Bi2Sr2CaCu20g, known as BSCCO-2212, a high-temperature superconductor with r<. = 95 K. It can be prepared in wire forms because it has layers of bismuth and oxygen atoms that YBCO does not have. BSCCO-2212 is so named because its formula consists of two bismuth, two strontium, one calcium, and two copper atoms. Other BSCCO compounds exist too, and they all have a general formula of Bi2Sr2Ca,Cu + 02 +6. BSCCO-2223, for example, which has the formula Bi2Sr2Ca2Cu30,o (where n = 2), is a superconductor with Tc= 107 K. 

IC -Advanced Superconductors manufactures superconductive wire, cable, and tape for MRI diagnostic systems, high-energy physics, and fusion power research. Products are based on NbTi, NbjSn, BSCCO (Bi-Sr-Ca-Cu-O) 2212/Ag, and BSCCO 2223/Ag multi-fUament wire and tape. 

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