A superconducting wire segment based on rare-earth barium copper oxide (REBCO) is the highest performing yet in terms of current density, carrying 190 MA/cm2 in the absence of any external magnetic field at a temperature of 4.2 K. At warmer temperatures of 20 K (which is the proposed application temperature for magnets used in commercial nuclear fusion reactors), the wires can still carry over 150 MA/cm2. These figures mean that the wire, despite being only 0.2 micron thick, can carry a current comparable to that of commercial superconducting wires that are almost 10 times thicker, according to its developers at the University at Buffalo in the US.
To read more, click here.