| 摘要 |
PURPOSE:To operate a correction coil in a superconducting state and to reduce in size a device by forming the coil made of a high temperature superconductor which becomes a superconducting state at a relatively high temperature on a heat shielding plate in a heat insulating layer for adiabatically insulating liquid helium. CONSTITUTION:A superconducting coil 3 of dipole structure formed of 2 layers on the outer periphery of a heat insulating layer 2 formed of 2 layers on the outer periphery of a ring vacuum tank 1 for storing an electron beam is provided. Liquid helium 5 for cooling the coil 3, and a heat shielding plate 7 provided in a heat insulating layer 6 for adiabatically insulating the helium 5 are provided, and held at liquid nitrogen temperature. A superconduction correcting coil 8 provided to correct a magnetic field by the coil 3 is of a dipole structure coil made of a high temperature superconductor exhibiting a superconducting state at higher liquid nitrogen temperature than the liquid helium temperature, and formed on the plate 7. With thus construction, the coil 8 is cooled to the liquid nitrogen temperature to be operated by superconduction. |
