Superconducting Magnet

A superconducting magnet is more than a coil of wire carrying current without resistance. It is a precision instrument where electromagnetic, thermal, mechanical, and cryogenic engineering converge to generate magnetic fields of extraordinary strength and stability. At Eata Electronic, we design and fabricate superconducting magnet systems spanning from compact 1 Tesla laboratory solenoids to complex multi-coil configurations exceeding 20 Tesla, each optimized for its intended application in research, medical imaging, or industrial processing.

What sets our magnet systems apart is the integration of in-house conductor production with electromagnetic design and cryogenic engineering. By controlling the superconducting wire that forms the heart of every coil, we eliminate the interface risks that arise when magnets are built from third-party conductors. This vertical integration translates directly into field quality, operational stability, and the ability to customize winding patterns, coil geometry, and cooling architecture to match requirements that no catalog product can satisfy.

Solenoid Magnets for Spectroscopy and Materials Research

The solenoid is the most fundamental superconducting magnet geometry, and for many applications, the most effective. A cylindrical coil wound from continuous superconducting wire generates a highly uniform axial field within the bore, with field homogeneity improving as the ratio of coil length to diameter increases. Our solenoid magnets utilize NbTi conductors for central fields up to approximately 9 Tesla at 4.2 K, and Nb3Sn inserts to extend the central field to 15 Tesla and beyond in standard bore sizes.

Field homogeneity is specified in parts per million over a defined diameter spherical volume, with our research-grade solenoids achieving better than 0.1 ppm over a 10 mm DSV for NMR pre-polarization and quantum computing applications. For material characterization work requiring optical or sample insertion access, we offer split-pair solenoids with horizontal or vertical gaps, where two coil halves are separated by a precisely controlled distance to allow beams, samples, or measurement probes to traverse the field region.

• Standard bore diameters: 25 mm, 54 mm, 100 mm, 150 mm, with custom sizes available
• Central field range: 1 T to 15 T (NbTi) and 15 T to 22 T (Nb3Sn insert configurations)
• Homogeneity options: 0.1 ppm to 100 ppm over specified DSV for various measurement techniques
• Persistent current switches for field drift below 0.01 ppm per hour without power supply

Figure 1: Split-pair superconducting magnet assembly with opposing coils and sample access gap

Cryogen-Free Conduction-Cooled Magnet Systems

Liquid helium has become an increasingly scarce and expensive resource in many regions, and the logistics of cryogen supply create operational dependencies that research laboratories and industrial facilities can no longer tolerate. Our cryogen-free superconducting magnets eliminate liquid helium entirely by connecting the magnet coil to the cold head of a closed-cycle cryocooler through a high-thermal-conductivity copper link. The coil and current leads are cooled by conduction, while radiation shields intercept thermal loads from the vacuum vessel walls.

Operating temperatures from 2.5 K to 10 K are achievable depending on cooler capacity and magnet heat load. At 4.2 K, our conduction-cooled NbTi magnets reach 9 Tesla in compact footprints suitable for laboratory benchtops, while Nb3Sn systems extend this to 14 Tesla without liquid cryogens. Every cryogen-free system we deliver includes integrated cryocooler, vacuum system, magnet power supply, and quench protection electronics in a turnkey configuration.

Figure 2: Compact cryogen-free superconducting magnet system with integrated cryocooler on laboratory bench

Dipole, Quadrupole, and Racetrack Magnets for Accelerators

Particle accelerators demand magnet geometries fundamentally different from solenoids. Dipole magnets bend particle trajectories with a transverse field, requiring C-shaped or H-shaped iron yokes with precisely shimmed pole faces to achieve field uniformity across the beam aperture. Quadrupoles focus particle beams with linear field gradients, calling for hyperbolic pole profiles and four-fold symmetry. Racetrack coils, formed from long straight sections joined by semicircular end turns, generate dipole fields without the iron saturation limitations of C-magnets, enabling fields above 10 T in compact accelerator arcs.

We have supplied accelerator magnets for synchrotron light sources, compact medical proton therapy cyclotrons, and beamline instrumentation at national laboratories. Key design considerations include AC loss management in ramped dipoles, precise field mapping and correction, and vacuum integration with beam pipes passing through the magnet aperture. Our NbTi accelerator magnets operate at fields up to 4.5 T in dipole configuration, while hybrid Nb3Sn designs push dipole performance toward 12 to 16 T for next-generation collider programs.

Figure 3: Cross-sectional view of a C-type superconducting dipole magnet with iron yoke and beam pipe

Superconducting Magnet System Specifications

The table below summarizes the operating parameters and application domains for our principal magnet system categories. Selection depends on required field strength, bore size, field uniformity, temporal stability, and cooling infrastructure.

High-Field and Hybrid Magnet Systems

Pushing beyond the practical limits of any single superconductor demands hybrid configurations that combine multiple conductor technologies within a single magnet system. Our high-field systems typically employ an LTS outsert of NbTi and Nb3Sn coils generating a 10 to 15 Tesla background field, within which an HTS insert coil of REBCO or Bi-2212 tape contributes an additional 5 to 12 Tesla. The resulting all-superconducting hybrid achieves central fields of 20 to 32 Tesla in useful bore diameters, rivaling the performance of much larger resistive-superconducting hybrid facilities.

Mechanical stress management becomes the dominant design challenge at these field levels. Hoop stress in the innermost coils can exceed 300 MPa, requiring high-strength reinforcement materials such as Cu-Nb composites, stainless steel overbanding, or carbon fiber external supports. Electromagnetic forces between nested coils must be carefully balanced to prevent axial displacement, and quench protection must safely dissipate stored energies that can reach tens of megajoules without exceeding local temperature limits.

Figure 4: Precision CNC winding system depositing superconducting wire onto a cylindrical coil former

Quench Protection, Persistent Switches, and System Integration

A superconducting magnet stores enormous energy in its magnetic field. Should a localized region of the coil transition to the normal resistive state, a quench, that energy becomes heat concentrated in a small volume, with the potential to cause permanent damage within seconds. Every magnet system we produce incorporates a multi-layered quench protection strategy tailored to its stored energy, operating current, and cooling method.

Passive protection relies on cold diodes connected in parallel with coil sections, allowing current to bypass a quenching region. Active protection monitors voltage differences across coil segments, triggering external dump resistors or heater networks that propagate the quench uniformly to distribute the dissipated energy. For magnets operating in persistent mode, superconducting joints with resistances below 10 to the minus 12 ohms enable the coil to be short-circuited and disconnected from the power supply, maintaining field stability for months with drift rates below 0.01 ppm per hour.

Figure 5: Layered cross-section of a superconducting magnet cryostat showing vacuum jacket, radiation shields, and coil assembly

Custom Magnet Design & Engineering Services

Beyond our standard platforms, Eata Electronic maintains an active custom magnet engineering group capable of designing entirely novel coil geometries for specialized applications. The process begins with your specification: field strength, bore geometry, spatial homogeneity, temporal stability, access ports, and constraints on mass, volume, or cryogenic infrastructure. Our electromagnetic designers then optimize coil winding patterns using finite-element analysis, followed by structural, thermal, and quench behavior modeling to ensure the design is both manufacturable and reliably operable.

Recent custom projects include a 6 Tesla split-pair magnet with 200 mm horizontal gap for neutron scattering experiments, a compact 3 Tesla conduction-cooled magnet system for semiconductor wafer parametric testing, and a 12 Tesla Nb3Sn solenoid with integrated gradient coils for preclinical magnetic particle imaging. Whether your requirement is a single research magnet or a production program of industrial systems, we invite you to discuss your project with our engineering team.

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