Comparative Analysis of Cubic Permanent Magnet and C-Electromagnet for Laser-EMAT Integrated System

The cube permanent magnet and C-type electromagnet, which can generate transverse magnetic fields, are analyzed in detail. Both of them combine with racetrack coil to form a Laser-EMAT integrated system to receive the out-plane vibration velocity of particles. The simulation results show that the diameter of the hole used to pass through the laser has little effect on the flux density generated in the specimen, whether it is a cube magnet or a C-type electromagnet. For the cube magnet, the intensity of the transverse magnetic field converted by 90-degree rotation is half that of the longitudinal magnetic field. The magnetic field strength in the specimen is not affected within the lift-off of 4mm between the permanent magnet and the specimen. Finally, the experiment verifies the correctness of the simulation result that both of the magnet and C-electromagnet can generate a transverse magnetic field for the flaw detection of the Laser-EMAT integrated system.