PPT-Numerical Analysis of Gradient-Induced Eddy Current in a Superconducting MRI Magnet

Institute of Electrical Engineering Chinese Academy of Sciences Beijing 100190 China College of Electrical and Information Engineering Hunan University Changsha 410082 China Chaoqun Niu. It is used for measuring targets made of electrically conductive materials which may be either ferromagnetic or nonferromagnetic A highfrequency alternating current flows through a coil cast in the sensor housing The electromagnetic coil field induc Lee Jr Induced is a term implying that a particular condition is indirectly caused by another condition In the case of traffic volumes the term arose from the phenomenon that improvements to a highway especially capacity improvements seemed to res magnetism. Faraday’s Law of Electromagnetic Induction. induced currents. electric generator. eddy currents. Electromagnetic Waves (Maxwell & Hertz). 1. Basic facts of Magnetism. Oersted. . discovered that a compass needle responded to the a current in a loop of wire. EDDY CURRENTS SEPARATOR. Eddy . currents. are . an. . electrical. . phenomenon. . that. . occurs. . when. a conductor . goes. . through. a variable . magnetic. . field. . . This. . relative. Insert student pic…. When Eddy gets out of the taxi . in the. . morning he will put his school bag at the classroom door.. Eddy then plays in the playground until the bell rings.. When the bell rings Eddy will line up with his class.. Eddy current inspection is one of several NDT methods that use the principal of “electromagnetism” as the basis for conducting examinations. .. Eddy currents are created through a process called electromagnetic induction. When alternating current is applied to the conductor, such as copper wire, a magnetic field develops in and around the conductor. This magnetic field expands as the alternating current rises to maximum and collapses as the current is reduced to zero. If another electrical conductor is brought into the close proximity to this changing magnetic field, current will be induced in this second conductor. Eddy currents are induced electrical currents that flow in a circular path. They get their name from “eddies” that are formed when a liquid or gas flows in a circular path around obstacles when conditions are right.. How Many Magnets Operational?. Spares Situation?. General Condition?. What makes up the Booster?. . (. Magnet wise, that is. . .. . ). 1 – 400 . MeV. transport line.. 8 Bends . Tom Peterson, . SLAC . USPAS. January, 2017. January, 2017 USPAS. Superconducting Magnets Tom Peterson. 2. O. utline . Introduction – magnet thermal design issues . An example of thermal considerations for forced-flow, normal helium I cooling – . Burba. , G., 2013. Eddy Covariance Method for Scientific, Industrial, Agricultural and Regulatory Applications: A Field Book on Measuring Ecosystem Gas Exchange and Areal Emission Rates. . LI-COR . Biosciences, Lincoln, . Claudio Sanelli. March 19, 2012. Preliminary Questions - 1. . Some preliminary questions should be clarified to better understand the problems and to make a more clear and precise cost evaluation. Just as an example:. . Gijs de Rijk. CERN. 10. th. April 2019. Magnet types: field. 1.5 - 2T resistive (Cu or Al coils, steel yoke, all warm), ramp rates 10 . th. T/s, ~40kCHF/m. 2 - 3 T . Superferric. (Superconducting, . Magnetic Field. While MRI is considered to be a safe imaging technique, it is not without hazards. The magnet field will attract many ferromagnetic metals in an uncontrolled fashion and cause them to fly towards the magnets bore and turning them into high velocity projectiles. The bore of the magnet is where the fringe field is strongest, as all the lines of force are constricted and their relative strengths heightened. Various objects can be considered projectiles. Quadrupole. Dipole magnets. A dipole magnet gives a constant B-field.. The field lines in a magnet run from North to South. . The field shown at right is positive in the vertical direction.. Symbol convention:. John Kakareka. Signal Processing and Instrumentation Section, . Division of Computational Bioscience, Center for Information Technology. NIH. Conflict of Interest Statement. I have no financial relationships regarding the .