Quenching of a superconducting coil with metal vessels is affected by
the induced current. A numerical calculational method in which vessels
are treated as coils is used, taking account of the influence on the
magnet generated by the induced current. The calculational results sho
w that the profile of the superconducting current decay strongly depen
ds on the helium vessel's resistance. Furthermore, the temperature at
the superconducting coil is lower as the resistance of the helium vess
el is lower. Use of the helium vessel with low resistance is demonstra
ted as having an effect of delaying the time when the magnetic field b
egins to decrease.