The Iron Horse

FLAGSHIP ELECTROMAGNET PLATFORM

The Iron Horse is Highfield's workhorse pulsed magnet — the production implementation of the CHRONOS-100 tier. Where the CHRONOS-100 specification defines the physics target, the Iron Horse is the engineering object that ships to customers and operates in the field.

The core challenge: generate high-field pulses repeatedly without destroying the magnet. Every component of the Iron Horse was designed around this constraint. Current performance: 20T sustained, with the 100T pulsed target driving ongoing development.

The REBCO conductor is wound onto precision-machined steel mandrels using a proprietary tension-control winding system that maintains constant hoop prestress across the coil cross-section. Zylon fiber (poly-p-phenylene-2,6-benzobisoxazole) is co-wound between conductor layers — it provides tensile strength exceeding carbon fiber at a fraction of the cross-section area, while being electromagnetically transparent. At 100 Tesla, the Zylon takes the mechanical load that would otherwise fracture the superconductor tape.

The cryocooler array consists of four Turbo-Brayton closed-cycle units delivering 3 kW of cooling at 20K each. No liquid helium is used or stored on-site. This was a deliberate design decision: the Iron Horse is deployed to customer facilities — fusion labs, aerospace propulsion test stands — that cannot handle cryogen logistics. Cryocooler-only operation makes the Iron Horse shippable and field-operable by facilities staff without specialist cryogenic training.

Field homogeneity of ±0.01% over a 10 cm diameter sphere is achieved through an active shimming coil array integrated into the cryostat bore. Five independently driven correction coils cancel axial and radial field gradients in real time, using Hall probe feedback sampled at 100 kHz. This homogeneity spec is what qualifies the Iron Horse for materials science research applications beyond brute industrial compression — spectroscopy, quantum oscillation studies, and precision measurements at extreme fields.