SUPERCONDUCTING MAGNET APPARATUS, MAGNETIC RESONANCE IMAGING APPARATUS, AND METHOD FOR DEMAGNETIZING SUPERCONDUCTING MAGNET

• Main Authors: ICHIKI YOTA, FUJITA SHINJI, KODAMA KAZUMUNE
• Format: Patent
• Language: English; Japanese
• Published: 15.08.2022
• Subjects: BASIC ELECTRIC ELEMENTS; DIAGNOSIS; ELECTRICITY; HUMAN NECESSITIES; HYGIENE; IDENTIFICATION; INDUCTANCES; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MAGNETS; MEASURING; MEDICAL OR VETERINARY SCIENCE; PHYSICS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; SURGERY; TESTING; TRANSFORMERS

To provide a superconducting magnet apparatus, a magnetic resonance imaging apparatus, and a method for demagnetizing a superconducting magnet that can quickly demagnetize a superconducting magnet while reducing the amount of heat generated in a cryostat.SOLUTION: A superconducting magnet apparatus 100 comprises: a superconducting coil 1; a permanent current switch 2; a cryostat 3; an external resistance element 4 that attenuates energy stored in the superconducting coil 1 when the superconducting coil 1 is demagnetized; an external power supply 5 that can energize the superconducting coil 1 with a reverse current of a permanent current; and a breaker 6 that can freely cuts off the energization between the external power supply 5 and the superconducting coil 1. A magnetic resonance imaging apparatus includes such a superconducting magnet apparatus 100. A method for demagnetizing a superconducting magnet includes: causing the external power supply 5 to flow the reverse current of the permanent current; when the amount of current flowing through the permanent current switch 2 is reduced, switching the permanent current switch 2 to an off-state and switching the breaker 6 to an off-state; and causing a current flowing through the superconducting coil 1 to flow through the external resistance element 4 to demagnetize the superconducting magnet.SELECTED DRAWING: Figure 1 【課題】クライオスタットの内部における発熱量を抑制して超伝導磁石を急速に減磁させることができる超伝導磁石装置、磁気共鳴イメージング装置および超伝導磁石の減磁方法を提供する。【解決手段】超伝導磁石装置１００は、超伝導コイル１と、永久電流スイッチ２と、クライオスタット３と、超伝導コイル１を減磁させるときに超伝導コイル１に蓄積されたエネルギを減衰させる外部抵抗素子４と、超伝導コイル１に対して永久電流の逆電流を通電可能な外部電源５と、外部電源５と超伝導コイル１との間の通電を遮断自在である遮断器６と、を備える。磁気共鳴イメージング装置は、このような超伝導磁石装置１００を備える。超伝導磁石の減磁方法は、外部電源５から永久電流の逆電流を流し、永久電流スイッチ２に流れる電流量が低下したとき、永久電流スイッチ２をオフ状態に切り替えると共に、遮断器６をオフ状態に切り替え、超伝導コイル１に流れる電流を外部抵抗素子４に流して超伝導磁石を減磁させる。【選択図】図１