I’m watching a black disc of wonder material hovering over a bubbling bath of liquid nitrogen.
“This is superconducting magnetic levitation,” says magnet scientist Greg Brittles. “The closest you’ll get to magic in the real world.”
And magical it is.
The ceramic-like substance, called rare-earth barium copper oxide (REBCO), is suspended – half a centimetre-or-so – in mid-air above a strip of copper.
Poke it with a finger and it won’t budge, give it a push and it will spin without wanting to stop.
REBCO is what’s known as a superconductor. Materials that have near-zero electrical resistance. But most need to be cooled to insanely cold temperatures to take on their magical properties.
This superconducting material has special magnetic properties which are being used in fusion research
What’s special about REBCO is it becomes superconducting at a balmy (in the world of superconductors) minus 200 Celcius (minus 328 Fahrenheit), around the temperature of liquid nitrogen. Making them far more useful.
The attraction for magnet scientists like Greg Brittles is the role for high-temperature superconductors (HTS) in making nuclear fusion a practical reality.
Nuclear fusion has long promised near-limitless, zero-carbon electricity from abundant, naturally occurring elements. But has, since the 1950s, remained out of reach.
The challenge is how to create, then harness nuclear fusion – the same process that powers stars like our Sun – down here on Earth.
That is where the magnets come in.
“HTS magnets allow us to go to stronger magnetic fields than have ever been possible before,” he says. “And they allow us to do it in more compact devices.”
Greg is a lead scientist at Tokamak Energy, an Oxfordshire-based company that…
