PURPOSE: To lighten the noise generated during operation by installing an inclined magnetic field coil installed in a vacuum container onto a winding spool made of the nonmagnetic material which possesses high specific resistance and high thermal conductivity.
CONSTITUTION: A spool 17 onto which an inclined magnetic field coil 10 is wound is formed from a nonmagnetic material which possesses high heat conductivity and high specific resistance, and a thermal anchor 18 formed from a flexible nonmagnetic body having high heat conductivity connects the spool and a vacuum container 6. Onto a coil installation board 20, the inclined magnetic field coil 10, thermal anchor 18 and a damper 19 can be installed, and further, these bodies are installed into a hollow vacuum container 6. With such constitution, if a high frequency electric current is allowed to flow in the inclined magnetic field coil, said field coil is vibrated. Though this vibration is transmitted to the coil, the propagation of sound to the inside of the vacuum container is prevented, since air as vibration medium does not exist. Further, the vibration transmitted to the vacuum container is attenuated by receiving the spool by a vibrationproof member, and the sound transmitted to the outside of the vacuum container is reduced.
SAHO NORIHIDE
OGATA HISANAO
Next Patent: LOCAL INCLINED MAGNETIC FIELD COIL