Magnet designers look to the future of light sources with a new prototype
After more than 15 years of work, scientists at the DOE’s three national laboratories have managed to create and test a more powerful and advanced superconducting magnet made of niobium and tin for use in future generations of sources.
With enough strong light, you can see things that people once thought were impossible. Large-scale light source installations generate this powerful light and scientists use it to create more durable materials, build more efficient batteries and computers, and learn more about the natural world.
When it comes to building these massive facilities, space is money. If you get high-energy light rays from smaller devices, you can save millions in construction costs. Add to that the opportunity to significantly improve the capabilities of existing light sources, and you have the motivation behind a project that brings together scientists from three national laboratories in the U.S. Department of Energy.
This team has just achieved an important milestone in more than 15 years: they have designed, built and fully tested a new half-meter-long prototype magnet that meets the requirements for use. in existing and future light source installations.
The next step, according to Efim Gluskin, an excellent colleague at the DOE’s Argonne National Laboratory, is to enlarge this prototype, build one longer than a meter, and install Advanced Photon Source, the DOE’s Office of Science Users. Installation in Argonne. But while these magnets will be compatible with light sources like APS, the real investment made here is in the next generation of unbuilt facilities.
“The real scale of this technology is for future free electron laser installations,” Gluskin said. “If you reduce the size of the device, you reduce the size of the tunnel and by doing that you can save ten million dollars. That makes a huge difference. “
That long-term goal led Gluskin and his colleague Argonne to collaborate with scientists at the Lawrence Berkeley National Laboratory and the Fermi Accelerator National Laboratory in DOE Laboratories. Each laboratory has been searching for superconducting technology for several decades and in recent years has focused its research and development efforts on compounds that combine niobium and tin.
This material remains in a superconducting state – that is, it has no resistance to the current flowing through it – even if it generates large magnetic fields, which is perfect for building what are called corrugated magnets. Light sources such as APS produce photon rays (light particles) while circulating the energy emitted by electrons as they circulate inside a storage ring. Corrugating magnets are devices that convert this energy into light, and the higher the magnetic field with them, the more photons you can generate from a device of the same size.
There are some superconducting magnet inverters installed in the APS, but they are made of niobium-titanium. alloy, which has been the standard for decades. Soren Prestemon, chief scientist at Berkeley Lab, said niobium-titanium superconductors are good for low magnetic fields – they stop being about 10 tesla superconductors. (That’s 8,000 times more powerful than your typical fridge magnet.)
“Niobium-3-tin is a more intricate material,” Prestemon said, “but it is able to transport current to a higher area. It is superconducting up to 23 tesla and can carry three times the current of niobium-titanium in the lower areas. These magnets stay cold 4, At 2 Kelvin, which is at least about 450 degrees Fahrenheit, to keep superconductors. ”
Prestemon has been at the forefront of Berkeley’s niobium-3-tin program, which began in the 1980s. The new design was developed at Argonne, based on the previous work of Prestemon and his colleagues.
“It is the first niobium-3-tin inverter that meets current design specifications and is fully tested for the quality of the magnetic field for beam transport,” he said.
Fermilab started working with this material in the 90s, according to Sasha Zlobin, who started and guided the niobium-3-tin magnet program there. Fermilab’s niobium-3-tin program is based on superconducting magnets for particle accelerators, such as the Large Hadron Collider CERN In Switzerland and the forthcoming PIP-II linear accelerator, to be built at the Fermilab site.
“We have shown success with high-area niobium-3-tin magnets,” Zlobin said. “We can apply this knowledge to superconducting inverters based on this superconductor.”
Part of the process, according to the group, is to avoid premature tightness in the magnets as they approach the desired magnetic field level. When magnets lose their ability to carry current without resistance, the reaction is called tempering, which eliminates the magnetic field and can damage the magnet itself.
The Group will report in its Transaction on Superconductivity Applied in IEEE Operations that its new device takes up almost twice the amount of current with a higher magnetic field than the niobium-titanium superconductors currently in APS.
The project is based on Argone’s experience in building and exploiting superconducting undulating waves and Berkeley’s and Fermilab’s knowledge of niobium-3-tin. Fermilab helped guide the process by advising on the selection of superconducting wires and sharing the latest developments in their technology. Berkeley designed a state-of-the-art system that uses advanced computer techniques to detect and protect the magnet.
At Argonne, the prototype was designed, manufactured, assembled and tested by a team of engineers and technicians under the guidance of project director Ibrahim Kesgin, who assisted in the design, construction and testing of the APS superconducting corrugator group led by Yury Ivanyushenkov. .
The research team plans to install a full-size prototype, which should be completed next year, in Sector 1 of the APS, which uses high-energy photon beams to study thicker samples of material. It will be demonstrable for the device, showing that it can work with design specifications in a light source. But the eye, Gluskin says, is on transferring two technologies, niobium titanium and niobium-3-tin, to industry partners and manufacturing these devices for future high-energy light sources.
“The key has been stable and sustainable work, supported by laboratories and DOE research and development funds,” Gluskin said. “Gradually progress has been made to get to this point.”