BOBBIN FOR SUPERCONDUCTIVE MAGNET USING GIFFORD-MCMAHON CRYOCOOLER

摘要

A bobbin for superconductive magnet adopting a conductive cooling system using a GM(Gifford-McMahon) cryocooler is provided, in which the bobbin includes a bobbin constituted by a central insulating portion and upper and lower conduction portions each of which has an end coupled to both ends of the central insulating portion and the other end with edges, the bobbin having a superconductive coil being wound along the outer periphery thereof and fixed to the edges of upper and lower conduction portions of the bobbin; a rectangular thermal capacitor having a side an upper end of which being perpendicularly coupled with a lower end of a head portion of the GM cryocooler; a conductive cooling rod having an end coupled with upper and lower ends of the other side of the thermal capacitor, with an insulation member interposed between the conductive cooling rod and the thermal capacitor, the conductive cooling rod having the other end coupled to sides of edges of the bobbin; a rod cable serving as a current lead-in portion, and which is coupled to sides of the edges of the bobbin so as to apply an electric power from a power source to the bobbin; and a pair of diodes connected in parallel to a protrusion formed at the other sides of the edges. The bobbin of the present invention provides advantages as follows; difficulty of electrical insulation between the current lead-in portion and bobbin is eliminated through the bobbin which is coupled in three stages by upper and lower conduction portions and central insulating portion; thermal conductivity is improved through the thermal capacitor, conduction cooling portion and thermal anchor; mechanical strength of the bobbin is improved through the press plate, grooves for soldering and thermal anchor; and the current is by-passed upon breakdown of the magnet, and electrical energy is emitted in a thermal energy, to thereby prevent local concentration of heat.