|
Article information
2025 , Volume 30, ¹ 2, p.5-18
Koldanov V.A., Sidorov A.V., Semenov V.E.
Numerical simulation of the interaction of electromagnetiv radiation with a smoothly inhomogeneous plasma
The research addresses numerical modelling for the process of the interaction of electromagnetic radiation with a spatially inhomogeneous plasma in the case of low frequency of electron collisions when there is a plasma resonance region. In order to compare the numerical results with analytical predictions, it was decided to simulate the linear problem of the incidence of an electromagnetic beam at a given angle onto a given smoothly inhomogeneous plasma layer. The simulation was carried out using the widely used FDTD method, which consists of directly solving Maxwell’s equations on a cross spatial grid. The influence of plasma was taken into account within the Drude model. A feature of this model is the use of a pulse source with a diagnostic pulse duration of about 5 periods of the central frequency. The computations has demonstrated the presence of numerical artifacts, which can serve as an unambiguous criterion for the unreliability of the simulation results. According to theoretical predictions, plasma oscillations cannot transform back into electromagnetic waves. So the time dependence of the reflected power should show one single pulse, corresponding to the partial reflection of the incident pulse from the plasma. However, calculations have shown that after some rather long time period after the first reflected pulse, additional pulses are observed in a number of cases. It happened due to the repeated emission of energy stored in the plasma in the form of plasma oscillations, called as “plasma echo”. Detailed studies have shown that echo pulses arise as a result of replacing the smooth plasma profile with a stepwise approximation. In our opinion, “plasma echo” pulses are not the effect of numerical procedure. To experimentally observe this effect, several rather exotic conditions must be met simultaneously. For the case of a smoothly inhomogeneous plasma, “plasma echo” is a parasitic effect. The paper proposes two cost-effective methods to reduce the influence of this parasitic effect without significantly slowing down the speed of calculations.
[link to elibrary.ru]
Keywords: numerical modelling, inhomogeneous plasma, plasma resonance
doi: 10.25743/ICT.2025.30.2.002
Author(s):
Koldanov Vladimir Alexandrovich
PhD. , Associate Professor
Position: Associate Professor
Office: Nizhny Novgorod State Engineering and Economic University
Address: 606340, Russia, Knyaginino, str.Oktyabrskaya, 22A
E-mail: vlad.kold@gmail.com
SPIN-code: 4777-0538Sidorov Alexander Vasilievich
PhD.
Position: Senior Research Scientist
Office: Institute of Applied Physics RAS
Address: 603950, Russia, Nizhny Novgorod, str.Ulyanova, 46
E-mail: alvasid@inbox.ru
Semenov Vladimir Evgenievich
Dr.
Position: Leading research officer
Office: Institute of Applied Physics RAS
Address: 603950, Russia, Nizhny Novgorod, str.Ulyanova, 46
References:
1. Taflove A.Computationalelectrodynamics: the finite-difference time-domain method. Boston: Artech
House; 1995: 611.
2. Gildenburg V.B. Resonance properties of inhomogeneous plasma structures. Soviet Physics JETP.
1964; 18(5):1359–1364. Available at: http://jetp.ras.ru/cgi-bin/dn/e_018_05_1359.pdf.
3. Ginzburg V.L. The propagation of electromagnetic waves in plasmas (2nd ed.). Oxford/N.Y.:
Pergamon Press; 1970: 615.
4. Kruer W.L. The physics of laser plasma interactions. N.Y.: Addison-Wesley; 1988: 182.
5. Gildenburg V.B. Nonlinear effects in an inhomogeneous plasma. Soviet Physics JETP. 1964;
19(6):1456–1461. Available at: http://jetp.ras.ru/cgi-bin/dn/e_019_06_1456.pdf.
6. Gildenburg V.B., Fraiman G.M. Deformation of plasma resonance region in a strong high-fre
quency field. Soviet Physics JETP. 1975; 42(5):816–818. Available at: http://jetp.ras.ru/cgi-bin/
dn/e_042_05_0816.pdf.
7. Eatabrook K.G., Valeo E.J., Kruer W.L. Two-dimensional relativistic simulations of resonance
absorption. Physics of Fluids. 1975; 18(9):1151–1159. DOI:10.1063/1.861276.
8. Bratman V.L., Zorin V.G., Kalynov Yu.K., Koldanov V.A., Litvak A.G., Razin S.V.,
Sidorov A.V., Skalyga V.A. Plasma creation by terahertz electromagnetic radiation. Physics of
Plasmas. 2011; 18(8):083507. DOI:10.1063/1.3622202.
9. Denisov G.G., Glyavin M.Yu., Fokin A.P., Kuftin A.N., Tsvetkov A.I., Sedov A.S.,
Soluyanova E.A., Bakulin M.I., Sokolov E.V., Tai E.M., Morozkin M.V., Proyavin M.D.,
Zapevalov V.E. First experimental tests of powerful 250 GHz gyrotron for future fusion research
and collective Thomson scattering diagnostics. Review of Scientific Instruments. 2018; 89(8):084702.
DOI:10.1063/1.5040242.
10. Glyavin M.Yu., Chirkov A.V., Denisov G.G., Fokin A.P., Kholoptsev V.V., Kuftin A.N.,
Luchinin A.G., Golubyatnikov G.Yu., Malygin V.I., Morozkin M.V., Manuilov V.N.,
Proyavin M.D., Sedov A.S., Sokolov E.V., Tai E.M., Tsvetkov A.I., Zapevalov V.E.
Experimental tests of a 263 GHz gyrotron for spectroscopic applications and diagnostics of various
media. Review of Scientific Instruments. 2015; 86(5):054705. DOI:10.1063/1.4921322.
11. Glyavin M.Yu., Luchinin A.G., Nusinovich G.S., Rodgers J., Kashyn D.G., Romero
Talamas C.A., Pu R. A 670 GHz gyrotron with record power and efficiency. Applied Physics
Letters. 2012; 101(15):153503. DOI:10.1063/1.4757290.
12. Shalashov A.G., Vodopyanov A.V., Abramov I.S., Sidorov A.V., Gospodchikov E.D.,
Razin S.V., Chkhalo N.I., Salashchenko N.N., Glyavin M.Yu., Golubev S.V. Observation
of extreme ultraviolet light emission from an expanding plasma jet with multiply charged argon or
xenon ions. Applied Physics Letters. 2018; 113(15):153502. DOI:10.1063/1.5049126.
13. Sidorov A.V., Razin S.V., Golubev S.V., Safronova M.I., Fokin A.P., Luchinin A.G.,
Vodopyanov A.V., Glyavin M.Yu. Measurement of plasma density in the discharge maintained in
a nonuniform gas flow by ahigh-power terahertz-wave gyrotron. Physics of Plasmas. 2016; 23(4):043511.
DOI:10.1063/1.4947219.
14. Rukhadze A.A., Tarakanov V.P. Reflection of an electromagnetic pulse from a subcritical wave
guide taper and from a supercritical-density plasma in a waveguide. Quantum Electronics. 2006;
36(9):883–888. DOI:10.1070/QE2006v036n09ABEH013290.
15. Hockney R.W., Eastwood J.W.Computersimulationusingparticles.N.Y.: McGrawHill; 1981: 540
Bibliography link:
Koldanov V.A., Sidorov A.V., Semenov V.E. Numerical simulation of the interaction of electromagnetiv radiation with a smoothly inhomogeneous plasma // Computational technologies. 2025. V. 30. ¹ 2. P. 5-18
|
