To efficiently cool a plurality of coils by independently cooling one coil of a split pair coils separately from the other coil by means of refrigerating machines.

A magnet system is a magnet used for neutron beam diffraction and three concentric aluminum rings and a fan-shaped aluminum spacer are arranged in a coil gap. The outermost aluminum ring is fixed to the bobbin of each coil and two coils are mechanically connected to each other. The coils are thermally connected to a two-stage thermal load flange 5 made of copper as a whole and the second stage 6 of one refrigerating machine R1 is connected to the flange 5. A copper heat conductor 4 from the bottom face of a lower coil C2 is thermally connected to the second stage 6 of the other refrigerating machine R2 on the outside of the fan-shaped aluminum spacer. The first stages of the refrigerating machines R1 and R2 are thermally brought into contact with a heat-shield plate 7.