Emergence of unusual metallic state supports role of "charge stripes" in formation of charge-carrier pairs essential to resistance-free flow of electrical current.
The compact coil could lead to a new generation of magnets for biomedical research, nuclear fusion reactors and many applications in between.
With funding from the National Science Foundation, scientists and engineers will determine the best way to build a new class of record-breaking instruments.
MagLab experts fine-tuned a furnace for pressure-cooking a novel superconducting magnet. Now they're about to build its big brother.
A material already known for its unique behavior is found to carry current in a way never before observed.
MagLab-industry partnership ups the critical current density of this high-temperature superconductor by a third.
Game-changing technology may hold the key to ever-stronger magnets needed by scientists.
This week at the lab, we're trying a magnet on for size.
A research magnet is made of a set of coils engineered from a current-carrying material — a fancy version of the electromagnet many kids make in school using a wire, battery and nail. Typically, four or five coils are slid one inside the next like Russian nesting dolls.
This week, we're slipping the second coil of the highly anticipated 32 tesla all superconducting magnet over the inner-most coil, then making any necessary adjustments. Like a good pair of jeans, the fit should be snug but not tight, with a mere millimeter between the two coils.
"Assembling the coils and the entire electrical circuit is an intricate job, and an exiting one," said project leader Huub Weijers. "After almost seven years of development, design, testing and construction of components, the final magnet is taking shape in front of our eyes."
These two coils, which contain about 6 miles of superconducting tape made of the novel, high-temperature superconductor yttrium barium copper oxide (YBCO). But YBCO is only one layer in this magnet. Those coils will soon be nested inside five more of coils made of conventional superconductors, three of niobium-tin and two of niobium-titanium.
The finished, 2.3-ton magnet system, when completed this summer, will join the MagLab’s roster of world-record magnets. At 32 tesla, it will be by far the strongest superconducting user magnet in the world, surpassing the current record of 23.5 tesla.
"It’s a difficult task to work through the many details of a new technology," said the magnet's lead designer Adam Voran, who managed the computer modeling for the project. "But the reward of seeing those meticulous designs being born into a tangible reality is exhilarating."
Photo by Stephen Bilenky / Text by Kristen Coyne.
This week at the lab, Peng Chen starts a new job at the Applied Superconductivity Center (ASC), where he will contribute to developing a groundbreaking magnet with bismuth-strontium-calcium-copper-oxide (Bi-2212), a promising high-temperature superconductor.
Chen's new job sounds a lot like his old job: building a groundbreaking magnet at the ASC with Bi-2212. The main difference is that last week, Chen was still a graduate research assistant. This week, he is a postdoctoral research associate, having graduated Saturday from Florida State University (FSU) with a Ph.D. in mechanical engineering.
"I can relax a little bit," laughed Chen, who has put in long hours over the past several months writing and revising his thesis.
In addition to designing and building world-record magnets used by scientists from across the globe, the MagLab has an important educational mission. This includes training early-career scientists like Chen. It's not by accident that undergraduates, graduate students and postdocs make up 40 percent of the lab's staff.
Since arriving here from China five years ago, Chen has experienced an intense, hands-on education among the team building a Bi-2212-based, high-field, high-homogeneity nuclear magnetic resonance magnet dubbed the Platypus. ASC Director David Larbalestier, who is Chen's advisor, said Chen has shown a lot of grit in the face of tough technical problems that come with building a first-of-its-kind instrument. In fact, ASC is hoping to get a patent out of a fully superconducting joint Chen built for the Platypus.
"He combines an engineering viewpoint with a strong desire to understand what he is doing, which makes his approach to complex technical problems very valuable," said Larbalestier, who placed the blue doctoral hood on Chen during his graduation ceremony to signify his former student’s new status.
Chen said he is looking forward to his new role on the team.
"In the transition from student to postdoc, you have more freedom," said Chen. "It's not only about your dissertation; you have more choices to do different aspects of the project and to collaborate with other teammates to support them — take more responsibility. I have a feeling I will do more and broaden my duties."
Text by Kristen Coyne / Photo courtesy of Peng Chen.
Nicolas Doiron-Leyraud of Canada's Université de Sherbrooke talks about his recent experiments on cuprate superconductors, why he chose physics over philosophy, and what makes the MagLab a great place to do science.