Superconducting tubular material for magnetic shielding.

摘要

A small tube (13) satisfying the following formula is fixed to the opening (for enabling the insertion of sensor, etc.) provided at the bottom or sidewall of a superconducting tubular material for magnetic shielding comprising a bottomed tubular substrate (20) and an oxide superconducting layer (21) formed on the substrate: <MATH> wherein L is a distance from the top end of the tubular material to the small tube, i.e. the opening of the tubular material; R is an inside diameter of the oxide superconducting layer in the tubular material; L1 is a length of the small tube; and R1 is an inside diameter of the oxide superconducting layer in the small tube. An oxide superconducting layer is formed on the small tube contiguously to the oxide superconducting layer (21) formed on the bottomed tubular substrate. The resulting superconducting tubular material for magnetic shielding restricts the penetration of a magnetic field into the tubular material through the opening. <IMAGE>