المؤلفون: Anderson, Paul¹ (AUTHOR), Finegold-Sachs, Lillian¹ (AUTHOR), Vahala, George¹ (AUTHOR) gvahala@gmail.com, Vahala, Linda² (AUTHOR), Ram, Abhay K.³ (AUTHOR), Soe, Min⁴ (AUTHOR), Koukoutsis, Efstratios⁵ (AUTHOR), Hizandis, Kyriakos^1,5 (AUTHOR)

المصدر: Radiation Effects & Defects in Solids: Incorporating Plasma Techniques & Plasma Phenomena. Jan/Feb2023, Vol. 178 Issue 1/2, p72-82. 11p.

مصطلحات موضوعية: *ELECTROMAGNETIC wave propagation, *KORTEWEG-de Vries equation, *UNITARY operators, *REFRACTIVE index, *ALGORITHMS

مستخلص: A qubit lattice algorithm (QLA), which consists of a set of interleaved unitary collision-streaming operators, is developed for electromagnetic wave propagation in tensor dielectric media. External potential operators are required to handle gradients in the refractive indices, and these operators are typically non-unitary but sparse. A similar problem arises in the QLA for the Korteweg–de Vries equation, as the potential operator that models the KdV nonlinear term is also non-unitary. Several QLAs are presented here that avoid the need of this non-unitary potential operator by perturbing the collision operator. These QLAs are fully unitary. [ABSTRACT FROM AUTHOR]

المؤلفون: Yarkov, A. A.^1,2 (AUTHOR) a12l@mail.ru, Rumyantsev, D. A.¹ (AUTHOR), Chistyakov, M. V.¹ (AUTHOR)

المصدر: Physics of Atomic Nuclei. Dec2022, Vol. 85 Issue 9, p1566-1569. 4p.

مصطلحات موضوعية: *ELECTROMAGNETIC wave propagation, *MAGNETIC fields, *PHOTONS, *LIGHT absorption

مستخلص: The process of electromagnetic wave propagation in a strongly magnetized (magnetic fields exceeding G) charge-symmetric plasma is investigated. Taking the change in the dispersion properties of a photon in a magnetic field and plasma into account, it is found that, as in the case of a pure magnetic field, the process of photon damping in a magnetized plasma has a nonexponential character. It is shown that the effective photon absorption width is significantly smaller in comparison with the results in the literature. [ABSTRACT FROM AUTHOR]

المؤلفون: Pokhrel, Santosh, Shankar, Varun, Simpson, Jamesina J.

المصدر: IEEE Transactions on Antennas & Propagation. Sep2018, Vol. 66 Issue 9, p4772-4781. 10p.

مصطلحات موضوعية: ELECTROMAGNETIC wave propagation, FINITE difference time domain method, CURRENT density (Electromagnetism), MAGNETIZATION, MAGNETIC anisotropy

مستخلص: A new finite-difference time-domain (FDTD) algorithm for electromagnetic wave propagation in magnetized plasma is proposed. This algorithm permits the use of two time step increments: one for Maxwell’s equations, ${\Delta t}$ , and the other for the current density equation derived from the Lorentz equation of motion, ${\Delta }{t}_{c}$. A major advantage of this algorithm over previous approaches is that only a single update iteration is needed for the current density equation even when ${\Delta }{t}_{c}<\Delta t$. This provides significant time savings that can make previously infeasibly long simulations now practical. The algorithm’s implementation is also relatively simple and it has relatively low memory requirements. The algorithm is validated against analytical results. A stability analysis is performed. [ABSTRACT FROM AUTHOR]

: Copyright of IEEE Transactions on Antennas & Propagation is the property of IEEE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Vahala, George¹ (AUTHOR) gmvaha@wm.edu, Vahala, Linda² (AUTHOR), Soe, Min³ (AUTHOR), Ram, Abhay K.⁴ (AUTHOR)

المصدر: Radiation Effects & Defects in Solids: Incorporating Plasma Techniques & Plasma Phenomena. Nov-Dec2020, Vol. 175 Issue 11/12, p986-990. 5p.

مصطلحات موضوعية: *ELECTROMAGNETIC wave propagation, *THEORY of wave motion, *MAXWELL equations, *ALGORITHMS

مستخلص: A three-dimensional quantum lattice algorithm (QLA) for electromagnetic wave propagation is being developed by stitching together the individual QLAs for 1D wave propagation in the three orthogonal Cartesian directions [ABSTRACT FROM AUTHOR]

المؤلفون: Davidovich, M. V.

المصدر: Technical Physics; Jul2022, Vol. 67 Issue 7, p549-562, 14p

مصطلحات موضوعية: PLASMA waves, NONLINEAR integral equations, QUANTUM tunneling, THIRD harmonic generation, ELECTROMAGNETIC wave propagation, ELECTROMAGNETIC pulses, ELECTROMAGNETIC waves

مستخلص: The propagation of a strong plane electromagnetic wave from vacuum through a bounded plasma layer is considered taking into account nonlinearity under tunneling and transparency conditions. The plasma is considered to be cold and nonmagnetic, and the electromagnetic pulse to be quasi-monochromatic, but short (i.e., not heating the plasma layer during its passage through it). The temperature dependence is not taken into account. The nonlinearity is taken into account phenomenologically as a dependence of the plasma frequency and collision rate on the field square averaged over the period. Associated stationary nonlinear integral equations for field harmonics, as well as a nonlinear integral equation for a nonstationary process, are obtained. The rate and time of tunneling in linear and nonlinear cases, the field distribution, and the third harmonic generation coefficient are determined. It is shown that tunneling takes longer than the passage through a transparent layer, and the nonlinear tunneling is a longer process compared to linear tunneling, while in all cases the time of the wave passage is longer when the time of passage through the equivalent length in vacuum at the speed of light. [ABSTRACT FROM AUTHOR]

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المؤلفون: Ratan, Naren

المساهمون: Norreys, Peter

مصطلحات موضوعية: 530.12, Wave propagation, Time-frequency analysis, Plasma physics, Plasma, Waves, Wavepackets

الوصف: This thesis presents results on the description of plasma waves in terms of wavepackets. The wave field is decomposed into a distribution of wavepackets in a space of position, wavevector, time, and frequency. A complex structure joining each pair of Fourier conjugate variables into a single complex coordinate allows the efficient derivation of equations of motion for the phase space distribution by exploiting its analytic properties. The Wick symbol calculus, a mathematical tool generalizing many convenient properties of the Fourier transform to a local setting, is used to derive new exact phase space equations which maintain full information on the phase of the waves and include effects nonlocal in phase space such as harmonic generation. A general purpose asymptotic expansion of the Wick symbol product formula is used to treat dispersion, refraction, photon acceleration, and ponderomotive forces. Examples studied include the nonlinear Schrödinger equation, mode conversion, and the Vlasov equation. The structure of partially coherent wave fields is understood in terms of zeros in the phase space distribution caused by dislocations in its complex phase which are shown to be correlated with the field entropy. Simulations of plasma heating by crossing electron beams are understood by representing the resulting plasma waves in phase space. The local coherence properties of the beam driven Langmuir waves are studied numerically.

الوصول الحر: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.740922Test

المؤلفون: Smith, T., Strong, K., Ibenki, S., Sen, S., Avasthi, D.

المصدر: Radiation Effects & Defects in Solids: Incorporating Plasma Techniques & Plasma Phenomena; Jan/Feb2022, Vol. 177 Issue 1/2, p198-205, 8p

مصطلحات موضوعية: GEOMAGNETISM, SHORTWAVE radio, RADIO waves, RADIO wave propagation, RADIO frequency, PLASMA waves

مستخلص: The interaction of radio frequency waves as it propagates through a plasma medium – has fascinated the plasma physicists for decades. The ionosphere is crucial for radio wave propagation. Short radio waves reflect from the F-layer and spread over long distances (up to two-three thousand kilometers) due to a high altitude of the layer. Long and medium radio waves propagate in the E- and D-layers. The anisotropy of ionospheric plasma due to the Earth's magnetic field accounts for the presence of two radio wave components, ordinary (O-mode) and extraordinary (X-mode). Powerful, high-frequency (HF) radio waves can be used to temporarily modify the ionosphere. These controlled, active experiments have proven useful both for studies of the natural upper atmosphere through observations of the ionospheric response to HF-induced perturbations, and for basic physics investigations exploiting the ionosphere as a large, natural plasma laboratory-without-walls. Here, we study these wonderful aspects through a student project. [ABSTRACT FROM AUTHOR]

: Copyright of Radiation Effects & Defects in Solids: Incorporating Plasma Techniques & Plasma Phenomena is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المساهمون: Kalmykov, S. [Univ. of Nebraska, Lincoln, NE (United States). Dept. of Physics and Astronomy]

وصف الملف: Medium: ED; Size: 20 p.

الوصول الحر: http://www.osti.gov/scitech/servlets/purl/1334788Test

المؤلفون: Labrunie, Simon, Zaafrani, Ibtissem

المصدر: ESAIM: Control, Optimisation & Calculus of Variations; 6/18/2021, p1-46, 46p

مصطلحات موضوعية: LOW temperature plasmas, ELECTRODYNAMICS, ELECTROMAGNETIC wave propagation, EXPONENTIAL stability, PLASMA waves, ELECTROMAGNETIC wave absorption

مستخلص: We consider a linearized Euler–Maxwell model for the propagation and absorption of electromagnetic waves in a magnetized plasma. We present the derivation of the model, and we show its well-posedeness, its strong and polynomial stability under suitable and fairly general assumptions, its exponential stability in the same conditions as the Maxwell system, and finally its convergence to the time-harmonic regime. No homogeneity assumption is made, and the topological and geometrical assumptions on the domain are minimal. These results appear strongly linked to the spectral properties of various matrices describing the anisotropy and other plasma properties. [ABSTRACT FROM AUTHOR]

: Copyright of ESAIM: Control, Optimisation & Calculus of Variations is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المصدر: 2011 AGU Fall meeting/San Francisco, CA 12/6/11; Conference: 2011 AGU Fall meeting/San Francisco, CA 12/6/11

وصف الملف: Medium: ED

الوصول الحر: http://www.osti.gov/scitech/servlets/purl/1036305Test