Split Coil magnet
Optics, nanoscience and semiconductor research will receive a boost this summer with the debut of the National High Magnetic Field Laboratory’s Split Magnet system, a custom-built, $2.5-million instrument with the potential to (literally) open up high-field magnet research. The magnet is successfully operating at 25 tesla; the standing record for this type of magnet was 17.5 tesla.
The magnet’s design required engineers to rethink the structural limits of resistive magnets, then invent, patent and find (sometimes elusive) builders for the technology that could carry their idea through. The Split Magnet features four large elliptical ports that enable scientists direct, horizontal access to the magnet’s central experimental space, or bore, while maintaining a high magnetic field. “Tesla” is a measurement of the strength of a magnetic field; 1 tesla is equal to 20,000 times the Earth’s magnetic field.
Split magnets are typically lower-field, less efficient systems with pencil-sized access ports. The elliptical-shaped ports visible in the accompanying photo enlarge the previously pencil-sized access for experiments by several hundredfold, a capability the laboratory’s user community has long desired.
This engineering feat represents years of intense collaboration between the lab’s engineering and research teams, headed by Magnet Science and Technology Scholar/ Scientist Jack Toth. Magnets are created by packing together dense, high-performance copper alloys and running a current through them, and all the magnet’s tremendous forces are focused on the center of a magnet coil — right where Toth and his team engineered the four large ports. Building a magnet system including such ports strong enough to withstand such high magnetic fields and such a heavy power load (at 28 megawatts, the power consumption of the magnet is exceeded only by the 45 tesla hybrid magnet) was at first deemed impossible.
While the technological breakthroughs enabling this magnet’s construction are important, the multidisciplinary research possibilities it allows are even more exciting. Optics researchers in chemistry, physics and biology are poised to conduct research using the split coil, and the magnet’s first user, travelling from Kent State, has already begun conducting experiments.