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Science Newsletter of the Faculty fo Physics
This is a new bulletin, which, as we hope, will bring fresh, updated information on scientific news, research activities, and related events in the life of our department to our staff members, undegraduate and graduate students, postdocs, collaborators and partners. We greatly hope that this Science Newsletter will help us to find new partners in research and shorten the way from fundamental research to applications and innovations, from our fundamental discoveries to their successful implementations in not too distant future.
XIV National School-Seminar "Wave phenomena in inhomogeneous media"
The conference papers from the School-Seminar «Waves-2014» will be submitted for publishing in the Memoirs of the Faculty of Physics journal.
| Journals » Memoirs of the Faculty of Physics » Issues » 2014 » # 5 |
Determination of the parameters of a high power ultrasound transducer to provide certain shock amplitude at the focus
P.B. Rosnitskiy, P.V. Yuldashev, V.A. Khokhlova
M. V. Lomonosov Moscow State University, Physics Faculty, Department of Acoustics. 119991, Moscow, Russia.Many modern medical applications of high intensity focused ultrasound rely on nonlinear acoustic effect of shock formation in the pressure waveform at the focus. The problem arises to determine parameters of the transducer that allow to obtain a certain value of the shock amplitude at the focus required for a specific application. It was proposed that the main transducer parameter, which determines the shock amplitude, is the transducer F-number. This hypothesis was tested using multi parameter numerical calculations of nonlinear ultrasound fields generated by such transducers. Khokhlov-Zabolotskaya-Kuznetsov equation was used in the modeling. The method to determine characteristic focal waveform with fully developed shock front was proposed. The approach was developed for calculating the shock amplitude between the time points at the specified level of the waveform time derivative. The magnitude of this level as relative to the maximum value of the derivative was determined by comparing heat deposition at the focus, calculated numerically and analytically using the weak shock theory. Characteristic shock amplitudes in the focal waveforms were calculated for transducers operating at 1 MHz frequency within the range of F-numbers from 0.8 to 2. It was shown that fully developed shock fronts of 80 MPa amplitudes correspond to transducers with F-number close to unity, which is a typical value for therapeutic transducers.
| URL: | http://uzmu.phys.sunmarket.com/abstract/2014/5/145314 |
| PACS: | 43.25.+y Nonlinear acoustics |
| UDC: | 534.7, 534.2 |
| Цитата: | П.Б. Росницкий, П.В. Юлдашев, В.А. Хохлова. Определение параметров ультразвукового излучателя для обеспечения определенной амплитуды ударного фронта в фокусе // Учен. зап. физ. фак-та Моск. ун-та. 2014. № 5. 145314 |