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1.
In the presence of an applied static and uniform magnetic field, a cylindrical Kadomtsev-Petviashivili equation is derived for a relativistic electromagnetic solitary wave propagating in collisionless plasma consisting electrons, positrons, and ions in the case of weak relativistic limit. This equation is solved in a stationary frame to obtain explicit expression for the velocity, amplitude and width of solitons. The amplitude of the solitary wave has a maximum value at a critical αc of the ratio of the ion equilibrium density to the electron one, and it increases as the applied magnetic field becomes larger. 相似文献
2.
New electrostatic instabilities in the plasma shock front are reported. These instabilities are driven by the electro- static field which is caused by charge separation and the parameter gradients in a plasma shock front. The linear analysis to the high frequency branch of electrostatic instabilities has been carried out and the dispersion relations are obtained numerically. There are unstable disturbing waves in both the parallel and perpendicular directions of shock propagation. The real frequencies of both unstable waves are similar to the electron electrostatic wave, and the unstable growth rate in the parallel direction is much greater than the one in the perpendicular direction. The dependence of growth rates on the electric field and parameter gradients is also presented. 相似文献
3.
A three-dimensional(3D)BurgersJ equation adopting perturbative methodology is derived to study the evolution of a shock wave with Landau quantized magnetic field in relativistic quantum plasma.The characteristics of a shock wave in such a plasma under the influence of magnetic quantization,relativistic parameter and degenerate electron density are studied with assistance of steady state solution.The magnetic field has a noteworthy control,especially on the shock wave's amplitude in the lower range of the electron density,whereas the amplitude in the higher range of the electron density reduces remarkably.The rate of increase of shock wave potential is much higher(lower)with a magnetic Held in the lower(higher)range of electron density.With the relativistic factor,the shock wave's amplitude increases significantly and the rate of increase is higher(lower)for lower(higher)electron density.The combined effect of the increase of relativistic factor and the magnetic field on the strength of the shock wave,results in the highest value of the wave potential in the lower range of the degenerate electron density. 相似文献
4.
Large Amplitude Low Frequency Waves in a Magnetized Nonuniform Electron-Positron-Ion Plasma
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Q.Haque H.Saleem 《中国物理快报》2004,21(5):884-887
It is shown that the large amplitude low-frequency electromagnetic drift waves in electron-positron-ion plasmas might give rise to dipolar vortices. A linear dispersion relation of several coupled electrostatic and electromagnetic low-frequency modes is obtained. The relevance of this work to both laboratory and astrophysical situations is pointed out. 相似文献
5.
Evaluation of Light Frequency Shift in a Caesium Beam Frequency Standard with Sharp Angle Incident Detecting Laser
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Light frequency shift measured in a small optically pumped caesium beam frequency standard is reported and analysed. Two light sources, the diffused laser light scattered from the caesium beam tube parts and the fluorescence light from the beam atoms excited by the laser light, for the light frequency shift are discussed. 相似文献
6.
Davoud Kamani 《International Journal of Theoretical Physics》2009,48(3):611-620
We study behaviors of a compact dimension and the T-duality, in the presence of the wrapped closed bosonic strings. When the closed strings interact and form another system
of strings, the radius of compactification increases. This modifies the T-duality, which we call it as T-duality-like. Some effects of the T-duality-like will be studied. 相似文献
7.
DENGBaiquan G.A.Emmert 《核工业西南物理研究院年报(英文版)》2002,(1):41-44
The fast ions, produced in D-3He fusion plasma, are the 14.7 MeV protons and 3.6 MeV α particles. Because their slowing down times are finite, therefore, they develop a certain amount of additional beta (fir) which has to be supported by the magnetic field. 相似文献
8.
José Ignacio Rosado 《Foundations of Physics》2011,41(7):1200-1213
The quantum state of a d-dimensional system can be represented by a probability distribution over the d
2 outcomes of a Symmetric Informationally Complete Positive Operator Valued Measure (SIC-POVM), and then this probability distribution
can be represented by a vector of
\mathbb Rd2-1\mathbb {R}^{d^{2}-1} in a (d
2−1)-dimensional simplex, we will call this set of vectors Q\mathcal{Q}. Other way of represent a d-dimensional system is by the corresponding Bloch vector also in
\mathbb Rd2-1\mathbb {R}^{d^{2}-1}, we will call this set of vectors B\mathcal{B}. In this paper it is proved that with the adequate scaling B=Q\mathcal{B}=\mathcal{Q}. Also we indicate some features of the shape of Q\mathcal{Q}. 相似文献
9.
A. Palit A. Panchenko N. G. Migranov A. Bhadra K. K. Nandi 《International Journal of Theoretical Physics》2009,48(5):1271-1289
Phase space method provides a novel way for deducing qualitative features of nonlinear differential equations without actually
solving them. The method is applied here for analyzing stability of circular orbits of test particles in various physically
interesting environments. The approach is shown to work in a revealing way in Schwarzschild spacetime. All relevant conclusions
about circular orbits in the Schwarzschild-de Sitter spacetime are shown to be remarkably encoded in a single parameter. The analysis in the rotating Kerr black hole readily exposes information as to how stability depends on the ratio
of source rotation to particle angular momentum. As a wider application, it is exemplified how the analysis reveals useful
information when applied to motion in a refractive medium, for instance, that of optical black holes. 相似文献
10.
12.
A parameter for evaluating the sensitivity of quantum vibrational energy to anharmonicity in a diatomic gasdynamic laser is defined and calculated by considering the corresponding diatomic molecules as quantum anharmonic oscillators under an interatomic Morse potential. The variation of the above parameter in terms of the vibrational states and in terms of an involved anharmonic coefficient is discussed. In particular, the parameter in question at the classical limit is examined. Both weak and strong anharmonicities are discussed. 相似文献
13.
The mesoscopic effect of spectral modulation is used to experimentally investigate the possible effect of a metal-coated SNOM tip on the intermodal dispersion of an optical fiber. Highly regular modulation registered in a fixed spectral region of the broadband light transmitted by a 200 nm SNOM tip yields the value of optical path difference (OPD) in the two-mode model. To investigate the origin of this OPD a series of spectral measurements accompanied with a gradual reduction of the multimode fiber tail length has been performed. The results indicate that the observed OPD consists of two clearly distinguishable contributions: the OPD in the non-coated multimode fiber and the OPD in the metal-coated SNOM tip. The first one is a result of the inherent modal dispersion of an optical fiber. A numerical consideration shows that the second one can be attributed to a mode-dependent contribution of surface plasmon polaritons: one of the two modes couples to plasmons stronger than the other one, resulting in a remarkably slower propagation. This leads to a completely different value of intermodal dispersion, which actually changes its sign in the SNOM tip. Proposed is a logical explanation for such kind of a sign-switching behavior. 相似文献
14.
We obtain a large positive lateral shift of a light beam reflected from a layered configuration due to the formation of the unusual standing wave, which acts like the forward surface wave. An explicitly analytic condition to obtain the large lateral shift is presented. Finally we present a numerical simulation for the lateral displacement of a Gaussian beam. 相似文献
15.
T. Kobayashi T. Kato Y. Matsuo M. Kurata-Nishimura Y. Hayashizaki J. Kawai 《Applied Physics A: Materials Science & Processing》2008,92(4):817-819
We investigate the so-called “matrix effect” on the relative intensities of ions in mixed solutions of alkali salts by using
femtosecond laser ablation time-of-flight mass spectrometry (fsLA-TOFMS). For the 1:1 mixed solution of sodium and potassium
salts, the intensity ratio of cations (Na+/K+) decreases as the total concentration increases. From the measurement for the mixed solution of lithium, sodium, potassium,
rubidium, and cesium solutions, we find out significant dependence of each ion intensity on the total concentration. The results
suggest that the electron transfer from neutral atoms to cations coexistent in the ablation plasma affects the relative ion
intensities observed with TOFMS when the total ion concentration is high. 相似文献
16.
D. S. N. Parker A. D. G. Nunn R. S. Minns H. H. Fielding 《Applied physics. B, Lasers and optics》2009,94(2):181-186
Tuneable, shaped, ultraviolet (UV) femtosecond laser pulses are produced by shaping and frequency doubling the output of a
commercial optical parametric amplifier (OPA). A reflective mode, folded, pulse shaping assembly employing a spatial light
modulator (SLM) shapes femtosecond pulses in the visible region of the spectrum. The shaped visible light pulses are frequency
doubled to generate phase- and amplitude-shaped, ultrashort light pulses in the deep ultraviolet. This approach benefits from
a simple experimental setup and the potential for tuning the central frequency of the shaped ultraviolet waveform. A number
of pulse shapes have been synthesised and characterised using cross-correlation frequency resolved optical gating (XFROG).
This pulse shaping method can be employed for coherent control experiments in the ultraviolet region of the spectrum where
many organic molecules have strong absorption bands.
D.S.N. Parker and A.D.G. Nunn contributed equally to this work. 相似文献
17.
18.
We examine in detail the theory of the intrinsic non-linearities in the dynamics of trapped ions due to the Coulomb interaction.
In particular, the possibility of mode–mode coupling, which can be a source of decoherence in trapped ion quantum computation,
or can be exploited for parametric down-conversion of phonons, is discussed and conditions under which such coupling is possible
are derived.
Received: 8 November 2002 / Published online: 26 March 2003
RID="*"
ID="*"Permanent address: MIP, Université Pierre et Marie Curie and Département de Physique, école Normale Supérieure, 75005
Paris, France
RID="**"
ID="**"Corresponding author. Fax: +1-505/667-1931, E-mail: dfvj@lanl.gov 相似文献
19.
We consider the effect of the multiple Coulomb scattering on the spatial dynamics of the relativistic hose instability of a relativistic electron beam propagating along an Ohmic plasma channel. It is shown that the enhancement of scattering noticeably suppresses this instability.
相似文献20.
The expressions for static displacements on the surface of a layered half-space due to static point moment tensor source are given in terms of the generalized reflection and transmission coefficient matrix method. The validity and precision of the new method is illustrated by comparing the consistency of our results with the analytical solution given by Okada‘s code employing the same point source and homogenous half-space model. The computed vertical ground displacement using the moment tensor solution of the Lanchang-Gengma earthquake displays considerable difference with that of a double couple component. The effect of a soft layer at the top of the homogenous half-space on a shallow normal-faulting earthquake is also analysed. Our results show that more seismic information would be obtained utilizing seismic moment tensor source and layered half-space model. 相似文献