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Time-Resolved High-Speed Visualization and Analysis of Underwater Shock Wave Focusing Generated by a Magnetic Pulse Compression Unit Daiki, Oshita S. Hamid R., Hosseini Yuta, Okuda Yuta, Miyamoto Takashi, Sakugawa Sunao, Katsuki Hidenori, Akiyama open access (C) 2012 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. Underwater shock wave magnetic pulse compression circuit high speed visualization cavitation bubble medical application Paper reports on visualization and analysis of underwater shock waves generation, focusing, and propagation. Recently, shock waves have been attractive with rising attention in medical field. Extracorporeal shock wave lithotripter has been one of its very successful applications. However, the effects of shock waves on living tissue are not sufficiently understood, due to unknown parameters involving the shock wave interaction. For better understanding of affecting points, a precise and controllable shock wave source is required. In this paper, in order to study shock wave effects, pulsed electric discharges produced by magnetic pulse compression circuit were used to generate underwater shock waves. A half-ellipsoidal reflector was used for shock wave focusing. The whole sequences of the shock wave generation, propagation, focusing, and cavitation bubbles, which appeared after shock wave passage, were visualized by time-resolved high-speed shadowgraph method. The peak pressure of shock wave focusing at second focal point reached 180 MPa. A cylindrical test section was used to observe phenomena around the electrode from the pulse discharge to bubble collapse. The first cavitation bubble's collapse occurred at about 750 μs. In the experiment, the two shock waves, one generated by expansion of plasma and another generated by collapse of the cavitation bubble were studied. Using high-speed visualization and image analysis, the velocity and pressure of the two shock waves were evaluated. The peak pressure of shock wave generated by bubble collapse reached 157 MPa. IEEE 2012-10 eng journal article AM http://hdl.handle.net/2298/0002000725 https://kumadai.repo.nii.ac.jp/records/2000725 https://doi.org/10.1109/TPS.2012.2187541 0093-3813 IEEE Transactions on Plasma Science 40 10 2395 2400 https://kumadai.repo.nii.ac.jp/record/2000725/files/10.1109_TPS.2012.2187541.pdf application/pdf 3.8 MB 2024-12-09