PROBLEM TO BE SOLVED: To provide a superconducting magnet device which has a simple constitution and can quickly consume accumulated magnetic energy when quenching has occurred, and to provide a magnetic resonance imaging device and a protection method of a superconducting coil.SOLUTION: A superconducting magnet device 1 includes superconducting coils 2a, 2b, 3a, 3b, 4a, and 4b a cooling container for storing the superconducting coils 2a, 2b, 3a, 3b, 4a, and 4b together with a cooling medium and cooling the superconducting coils a permanent current switch 6 which is connected to the superconducting coils 2a, 2b, 3a, 3b, 4a, and 4b in series for constituting a first closed circuit C1 and feeding a permanent current Ip a diode D which is connected to the superconducting coils 2a, 2b, 3a, 3b, 4a, and 4b in series separately from the first closed circuit C1 for constituting a second closed circuit C21 a thermoelectric transducer 10 which is thermally connected to the diode D and an electric heater 13 which is electrically connected to the thermoelectric transducer 10 and thermally connected to the superconducting coil 4a.COPYRIGHT: (C)2015,JPO&INPIT【課題】簡易な構成により、クエンチが発生した場合には蓄積された磁気エネルギを迅速に消費できる超電導磁石装置、磁気共鳴画像装置および超電導コイルの保護方法を提供する。【解決手段】超電導磁石装置1は、超電導コイル2a,2b,3a,3b,4a,4bと、超電導コイル2a,2b,3a,3b,4a,4bを冷媒と共に収納し冷却する冷却容器と、超電導コイル2a,2b,3a,3b,4a,4bに直列に接続して第1閉回路C1を構成して永久電流Ipを流す永久電流スイッチ6と、第1閉回路C1とは別に超電導コイル2b,4aに直列に接続して第2閉回路C21を構成するダイオードDと、ダイオードDに熱的に接続される熱電変換素子10と、熱電変換素子10と電気的に接続され、超電導コイル4aに熱的に接続される電熱ヒータ13とを有している。【選択図】図5
