System Design of a Magnetically Levitated Internal Coil Device Mini-RT

摘要

Synopsis:Mahajan-Yoshida proposed an idea for confining high-beta plasma utilizing a fast plasma flow in a toroidal direction.In addition,Hasegawa considered a dipole fusion reactor.Here,the authors introduce a"Mini-RT"internal coil device,in which a superconducting coil is levitated in a vacuum vessel and plasma is confined by a dipole magnetic field,to explore a new high-beta plasma for fusion research.The conductor of the floating coil(R_c=0.15 m,I_c=50 kA)is Bi-2223 tape that is cooled by cold helium gas to 20 K.By controlling the coil current of the levitation coil located at the top of the vacuum chamber,a few hours of levitation can be obtained for plasma experiments.It is possible to produce various magnetic configurations with a combination of vertical field coils.Several issues related to interaction with plasma produced around the floating coil have been taken into account for designing the floating coil;for example,clearance of the magnetic surface at the torus inner region,heat load to the floating coil caused by the plasma and so on.