SUPERCONDUCTING MAGNET FOR NUCLEAR MAGNETIC RESONANCE IMAGING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a superconducting magnet for MRI whose operation time is long even in the state that an extremely low temperature refrigerator is stopped, in a magnet for open type MRI for which superconducting coils are oriented opposingly in the vertical direction. SOLUTION: A gaseous helium storage container is provided inside a liquid helium storage container and pressure piping is connected. Since the storage container has a structure that the lower part is opened and the upper part is closed, evaporated gaseous helium is captured and stored. As a result, the evaporated gaseous helium pushes up the liquid level of liquid helium, and hence the temperature rise of the superconducting coil due to liquid level decline is suppressed. COPYRIGHT: (C)2005,JPO&NCIPI