Identyfikatory
Warianty tytułu
Języki publikacji
Abstrakty
The dynamics of slightly diverging two-dimensional beams whose direction forms a constant angle θ with the equilibrium straight magnetic strength is considered. The approximate dispersion relations and corresponding links which specify hydrodynamic perturbations in confined beams are derived. The study is dedicated to the diffraction of a magnetosonic beam and nonlinear thermal self-action of a beam in a thermoconducting gaseous plasma. It is shown that the divergence of a beam and its thermal self-action is unusual in some particular cases of parallel propagation (θ = 0) and has no analogues in the dynamics of the Newtonian beams. The nonlinear attenuation of Newtonian beams leads to their defocusing in gases, whereas the unusual cases correspond to the focusing in a presence of magnetic field. The examples of numerical calculations of thermal self-action of magnetoacoustic beams with shock fronts are considered in the usual and unusual cases of diffraction concerning stationary and non-stationary self-action. It is discovered that the diffraction is more (θ = 0) or less (θ = π/2) manifested as compared to that of the Newtonian beams. The beams which propagate oblique to the magnetic field do not reveal diffraction. The special case, when the sound and Alfvénic speeds are equal, is discussed. This magnetosonic beams incorporate acoustic and Alfvénic properties and do not undergo diffraction in this particular case.
Wydawca
Czasopismo
Rocznik
Tom
Strony
355--362
Opis fizyczny
Bibliogr. 14 poz., rys., wykr.
Twórcy
autor
- Gdansk University of Technology, Faculty of Applied Physics and Mathematics Gdansk, Poland
Bibliografia
- 1. Botha G.J.J., Arber T.D., Nakariakov V.M., Keenan F.P. (2000), A developed stage of Alfvén wave phase mixing, Astronomy and Astrophysics, 363(3): 1186-1194.
- 2. Callen J.D. (2003), Fundamentals of Plasma Physics, Lecture notes, University of Wisconsin, Madison.
- 3. Chin R., Verwichte E., Rowlands G., Nakariakov V.M. (2010), Self-organization of magnetoacoustic waves in a thermal unstable environment, Physics of Plasmas, 17: 032107, doi: 10.1063/1.3314721.
- 4. Duck F.A. (2002), Nonlinear acoustics in diagnostic ultrasound, Ultrasound in Medicine & Biology, 28(1): 1-18, doi: 10.1016/S0301-5629(01)00463-X.
- 5. Freidberg J.P. (1987), Ideal Magnetohydrodynamics, Plenum Press, New York.
- 6. Hamilton M., Blackstock D. [Eds] (1998), Nonlinear Acoustics, Academic Press, New York.
- 7. Krall N.A., Trivelpiece A.W. (1973), Principles of Plasma Physics, McGraw Hill, New York.
- 8. Kuznetsov V.P. (1971), Equations of nonlinear acoustics, Soviet Physics Acoustics, 16: 467-470.
- 9. Leble S., Perelomova A. (2018) The Dynamical Projectors Method: Hydro and Electrodynamics, CRC Press.
- 10. McLaughlin J.A., De Moortel I., Hood A.W. (2011), Phase mixing of nonlinear visco-resistive Alfvén waves, Astronomy & Astrophysics, 527: A149, doi: 10.1051/0004-6361/201015552.
- 11. Nakariakov V.M., Mendoza-Briceño C.A., Ibáñez M.H. (2000), Magnetoacoustic waves of small amplitude in optically thin quasi-isentropic plasmas, The Astrophysical Journal, 528(2): 767-775, doi: 10.1086/308195.
- 12. Rudenko O.V., Sapozhnikov O.A. (2004), Self-action effects for wave beams containing shock fronts, Physics-Uspekhi, 47(9): 907-922.
- 13. Rudenko O.V., Soluyan S.I. (1977), Theoretical Foundations of Nonlinear Acoustics, Plenum, New York.
- 14. Yufeng Z. (2015), Principles and Applications of Therapeutic Ultrasound in Healthcare, Taylor & Francis Inc.
Typ dokumentu
Bibliografia
Identyfikator YADDA
bwmeta1.element.baztech-6b46239b-3158-4e05-8815-5a9a479616eb