 In August, 2015, MIT announced a tokamak it named ARC fusion reactor using rare-earth barium-copper oxide (REBCO) superconducting tapes to produce high-magnetic field coils that it claimed produce comparable magnetic field strength in a smaller configuration than other designs.In October 2015, researchers at the Max Planck Institute of Plasma Physics completed building the largest stellarator to date, named Wendelstein 7-X.On December 10, they successfully produced the first helium plasma, and on February 3, 2016 produced the device's first hydrogen plasma.