Superconducting Wire

Multifilamentary superconducting wire lies at the heart of virtually every high-field magnet system operating today. At Eata Electronic, we supply precision-engineered NbTi, Nb3Sn, and MgB2 conductors in round wire, rectangular cable, and cable-in-conduit geometries, serving laboratories, medical imaging OEMs, and fusion energy consortia across the globe. Every strand we ship is characterized for critical current density, hysteresis loss, and residual resistivity ratio, giving magnet designers the confidence to specify our conductors for systems where performance directly determines experimental outcomes.

Drawing on metallurgical expertise refined through years of billet assembly, extrusion, and cold drawing operations, we control filament spacing, twist pitch, and copper ratio from raw material through final heat treatment. The result is a conductor with mechanical and electromagnetic properties that remain consistent across production lots, a factor that matters enormously when your magnet must train reliably or your accelerator cavity demands field uniformity within parts per million.

Niobium-Titanium (NbTi) Multifilamentary Wire

Niobium-titanium remains the workhorse of applied superconductivity, and for excellent reasons. With a critical temperature of 9.8 K and an upper critical field near 10.5 T at liquid helium temperature, NbTi offers an unmatched balance of performance, ductility, and cost for magnets operating below roughly 9 T. Our NbTi conductors are produced via the classical billet approach: NbTi alloy rods are arranged in a hexagonal array within a high-purity copper canister, extruded at elevated temperature, and drawn through diamond dies to final diameter with intermediate anneals to manage work hardening.

Filament diameters range from under 5 micrometers for AC-loss-sensitive applications such as accelerator magnets, up to several tens of micrometers for DC solenoids where stability against flux jumps takes priority. Copper-to-superconductor ratios from 1.5:1 to 10:1 are available, with higher ratios offering improved stability and lower operating temperature margin requirements. We routinely supply NbTi wire in the following configurations:

• Round wire from 0.1 mm to 2.0 mm diameter, with filament counts from 6 to over 10,000
• Rectangular cable (Rutherford-style) for compact, high-current-density windings
• Wire-in-channel and cable-in-channel integrated conductors with hollow copper profiles
• Enameled and insulated variants with polyimide or fiberglass braid wrap

Figure 1: Precision-wound NbTi multifilamentary wire on aluminum shipping reel

Niobium-Tin (Nb3Sn) High-Field Conductor

When the magnetic field exceeds what NbTi can tolerate, Nb3Sn steps in. This intermetallic A15 compound carries critical current densities exceeding 1,000 A/mm2 at 12 T and 4.2 K, making it indispensable for nuclear magnetic resonance spectrometers above 400 MHz, fusion reactor toroidal field coils, and high-field test facilities. The price for this performance is brittleness: Nb3Sn forms only during a high-temperature reaction heat treatment near 650 to 750 degrees Celsius, after which the conductor cannot be bent on a small radius without cracking the superconducting layer.

We manufacture Nb3Sn wire by three distinct routes, each offering a different trade-off between critical current, filament size, and mechanical properties. The bronze route embeds pure niobium rods in a Cu-Sn bronze matrix, yielding fine filaments ideal for AC applications but with moderate Jc. The internal-tin method surrounds a central tin core with niobium rods in a pure copper matrix, achieving significantly higher Jc through enhanced tin availability during reaction. For the most demanding high-field applications, our powder-in-tube process produces conductors with the highest critical current densities and finest filament microstructures available.

Figure 2: Macro photograph of a reacted Nb3Sn superconducting strand showing copper-clad surface detail

Cable-in-Conduit Conductors for Fusion & Large-Scale Magnets

Large fusion magnets and high-energy physics detectors require conductors that carry tens of kiloamperes while surviving enormous electromagnetic forces and nuclear heating. The cable-in-conduit conductor addresses this challenge by packing hundreds or thousands of superconducting strands into a stainless steel jacket with a central channel for forced-flow helium cooling. Our CICC offerings leverage both Nb3Sn and NbTi strands, cabled in multiple stages around a central spiral to achieve the required current capacity and mechanical flexibility.

Each CICC project demands bespoke engineering. Strand diameter, cabling pattern, void fraction, and jacket wall thickness are all optimized through electromagnetic, thermal-hydraulic, and structural finite-element analysis before manufacturing begins. We have supplied CICC components for tokamak toroidal field coils, central solenoid modules, and poloidal field systems, with strand counts ranging from a few hundred to over one thousand per cable.

Figure 3: Cutaway view of a cable-in-conduit conductor showing cabled strands within stainless steel jacket

Superconducting Wire Specifications

Engineers selecting a superconducting wire must weigh critical temperature, upper critical field, strain sensitivity, and AC loss characteristics against system requirements. The table below compares our principal conductor grades across key parameters.

Magnesium Diboride (MgB2) Wire for Cryocooler-Cooled Systems

Magnesium diboride occupies a compelling niche in the superconducting materials landscape. With a critical temperature of 39 K, it bridges the gap between low-temperature NbTi and Nb3Sn on one side and the expensive high-temperature cuprates on the other. Crucially, MgB2 retains useful critical current density at 20 K, the temperature readily achieved by compact closed-cycle cryocoolers. This eliminates the need for liquid helium entirely, dramatically reducing both capital cost and operational complexity for magnets operating below about 3 T.

Our MgB2 conductors are fabricated by the powder-in-tube method, in which a mixture of magnesium and boron powders is packed into a metallic sheath, typically iron or niobium, and drawn to final diameter. Reaction heat treatment between 600 and 950 degrees Celsius forms the superconducting MgB2 phase inside the sheath. We supply both ex-situ conductors, using pre-reacted MgB2 powder for simpler processing, and in-situ conductors, where the MgB2 forms during final heat treatment for superior grain connectivity and higher critical current.

Figure 4: Multi-die wire drawing line with coolant flow during conductor fabrication

REBCO Coated Conductor Cables for Ultra-High Field Applications

For magnetic fields beyond the reach of any metallic superconductor, REBCO coated conductor tapes assembled into cables offer an extraordinary combination of critical current and mechanical strength. Operating at 4.2 K, REBCO tapes carry thousands of amperes per square millimeter in fields exceeding 20 T, making them the only practical choice for next-generation fusion reactors, compact particle accelerators, and 40+ tesla all-superconducting user magnets.

Eata Electronic supplies REBCO tapes in CORC, twisted stacked, and Roebel cable configurations. Each design addresses specific electromechanical challenges: CORC cables wrap tapes around a central copper former for isotropic flexibility, twisted stacked arrangements maximize current density in solenoid windings, and Roebel transposition distributes current uniformly across all tapes while minimizing AC losses. Tape widths from 4 mm to 12 mm are available, with minimum critical currents specified at 77 K self-field, 4.2 K at 12 T perpendicular field, and under bending strain relevant to your coil diameter.

Figure 5: Rectangular Rutherford-style superconducting cables staged for magnet winding assembly

Quality Assurance & Characterization

Every spool of superconducting wire we produce undergoes a battery of tests before release. Critical current is measured on short samples at specified temperature and magnetic field using a 1 microvolt per centimeter electric field criterion. For Nb3Sn conductors, uniaxial strain dependence of Ic is characterized to provide scaling parameters for magnet design. Hysteresis loss is determined by vibrating sample magnetometry or AC susceptibility, while residual resistivity ratio quantifies the purity of the copper stabilizer. Dimensional verification includes diameter, ovality, and twist pitch measurement along the full production length.

Bespoke Conductor Development

Standard catalog products meet many requirements, but the frontier of superconducting technology often demands something unique. Our custom conductor development program engages your engineering team from concept through qualification, designing billet layouts, optimizing heat treatment schedules, and validating performance against your specification. Whether you need an NbTi wire with an unconventional filament array to minimize coupling loss in a ramped accelerator magnet, an Nb3Sn conductor with enhanced strain tolerance for a high-field insert coil, or an MgB2 wire with modified sheath composition for improved thermal conductivity, we have the metallurgical expertise and manufacturing flexibility to deliver. Prototype quantities and full production volumes are both within our capability.

For Research or Industrial Raw Materials, Not For Personal Medical Use!