共查询到20条相似文献,搜索用时 968 毫秒
1.
Bao-Liang Qian 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1999,27(6):1578-1581
An exact solution is found for the relativistic equation of motion of a charged particle driven by a circularly polarized electromagnetic wave and a constant magnetic field. The explicit expressions of particle position and velocity are obtained for certain initial conditions. The results are of interest to the interaction of the high-power laser with the magnetized plasma, electromagnetically pumped free-electron laser with a guide magnetic field, propagation of electromagnetic wave signals through a re-entry plasma sheath in the presence of a strong magnetic field, and magnetic confinement plasmas 相似文献
2.
A cold and uniform plasma-filled travelling wave tube with
sinusoidally corrugated slow wave structure is driven by a finite
thick annular intense relativistic electron beam with the entire
system immersed in a strong longitudinal magnetic field. By means of
the linear field theory, the dispersion relation for the relativistic
travelling wave tube (RTWT) is derived. By numerical computation, the
dispersion characteristics of the RTWT are analysed in different
cases of various geometric parameters of the slow wave structure and
plasma densities. Also the gain versus frequency for three different
plasma densities and the peak gain of the tube versus plasma density
are analysed. Some useful results are obtained on the basis of the
discussion. 相似文献
3.
Yu. V. Kirichenko 《Technical Physics》1999,44(6):709-711
A theoretical analysis is made of the conditions for generation of electromagnetic waves by a thin cylindrical layer of relativistic
electrons rotating in crossed axial magnetic and radial electrostatic fields in a cylindrical cavity. A dispersion equation
is obtained to describe the interaction between waves and electrons under plasma resonance conditions. The dependence of the
growth rates on the relativistic factor and the magnetic field are studied.
Zh. Tekh. Fiz. 69, 112–114 (June 1999) 相似文献
4.
In this work we investigate the effect of a relativistic homogeneous electron beam on the field stability and minimizing the energy losses in waveguide filled homogeneously with plasma. Analytical calculations are performed to find the plasma dielectric tensor by applying the boundary conditions at the plasma‐conductor interface. We derive the dispersion equations which describe the propagated E‐ and H‐waves and their damping rate. The necessary condition for the field stability in the waveguide and the amplification coefficient for the E‐wave are obtained. The effects of plasma warmness and an external static magnetic field are taken into consideration. Relativistic electron beam is found to play a crucial role in controlling the field attenuation in waveguide. 相似文献
5.
A. G. Khachatryan 《Journal of Experimental and Theoretical Physics》2002,94(3):516-520
The effect of a longitudinal magnetic field on the linear wake fields excited by a relativistic electron bunch in a cold homogeneous plasma is considered. The obtained results prove that the presence of an external magnetic field leads to a dependence of the wake wavelength on the transverse coordinate, to a change in the wave amplitude with increasing distance from the bunch, and to the emergence of anharmonicity. It is found that a strong magnetic field reduces the wave amplitude significantly for narrow bunches and changes the amplitude insignificantly for broad bunches. 相似文献
6.
Experimental results on interaction of a rotating relativistic electron beam with plasma and neutral gas are presented. The
rotating relativistic electron beam has been propagated up to a distance of 150 cm in a plasma. The response of the plasma
to the rotating electron beam is found to be of magnetic diffusion type over a plasma density range 1011–1013 cm−3. Excitation of the axial and azimuthal return currents by the rotating beam and subsequent trapping of the azimuthal return
current layer by the magnetic mirror field are observed. A field-reversed configuration has been formed by the rotating relativistic
electron beam when injected into neutral hydrogen gas. We have observed field reversal up to three times the initial field
in an axial length of 100 cm. 相似文献
7.
Lai C.H. Katsouleas T.C. Mori W.B. Whittum D. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1993,21(1):45-52
The interaction of a light wave with a relativistic ionization front in the presence of an applied DC magnetic field which is perpendicular or parallel to the incident wave is considered. In both cases, four transmitted modes are generated in the magnetized plasma by an incident linearly polarized wave. The frequency upshifts of the various modes are calculated and compared to the unmagnetized case. The corresponding reflection and transmission coefficients are also obtained. Finally, the density ripple associated with the free streaming mode in a magnetized plasma for the perpendicular case is discussed 相似文献
8.
Spatiotemporal Evolution of Intense Short Gaussian Laser Pulses in Weakly Relativistic Magnetized Plasma 下载免费PDF全文
The weakly relativistic regime of propagation of a short and intense laser pulse in the magnetized plasma is investigated. By considering relativistic nonlinearity and using non‐linear Schrödinger equation with paraxial approximation, two second‐order coupled differential equations are obtained for the longitudinal pulse width parameter (in time) and for the transverse pulse width parameter (in space). The simultaneous evolution of spot size and length of a relativistic Gaussian laser pulse in a magnetized plasma can be calculated by the numerical solution of the equations. The effect of magnetic field is investigated. It is observed that in the presence of magnetic field both the self‐compression and the self‐focusing can be enhanced. Furthermore, the interplay between the longitudinal self‐compression and the transverse self‐focusing in a magnetized plasma is investigated. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
9.
The dispersion relation for the interaction of a relativistic electron beam in a thermal plasma, in the absence of an external magnetic field, is studied. It is shown that there are two distinct beam-plasma branches present, and that one of them couples to the electromagnetic eigenmode of the beam-plasma system with a magnetic field and a Poynting flux associated with it. It is also shown that these branches can couple together. 相似文献
10.
H. Delibašić K. Isaković V. Petrović T. Miladinović 《International Journal of Theoretical Physics》2018,57(2):406-413
We theoretically improved the relativistic ADK formula for a linearly polarized laser field. We have taken into account the influence of the magnetic component of laser field on the transition rate, in near relativistic field intensity. It was shown that the magnetic component results in a decrease of the transition rate in comparison to the results obtained by the original relativistic expression. We gave considered noble and alkali atoms. The obtained results show that this influence is larger (more significant) for alkali atoms. 相似文献
11.
采用等效媒质处理方法来研究有限引导磁场下沿纵向运动的相对论环形电子注.首先建立运动坐标系以电子注纵向速度匀速运动,在运动坐标系中电子注可以被考虑成静止的磁化等离子体,再通过四维空间的洛伦兹变换得到电子注在静止的实验室坐标系下可以被等效为双各向异性媒质,其不仅具有张量形式的电导率和磁导率,还具有手征特性.在此基础上同时考虑了由于电子注表面波动所引起的表面电流密度.采用该方法研究了有限引导磁场下圆柱波导中沿纵向运动的相对论环形电子注,推导出该模型的色散方程,并进行了数值计算.计算结果表明该研究方法能够得到更准
关键词:
相对论环形电子注
磁化等离子体
色散特性 相似文献
12.
Summary In this paper the relativistic second-harmonic generation of a high-power laser radiation in a laser-produced plasma has been
studied theoretically in the presence of a self-generated magnetic field. The relativistic Vlasov equation has been employed
for the nonlinear response of the electrons in the hot magnetized plasma. It is observed that the power conversion efficiency
of the generated second harmonic wave is much higher for relativistic calculations than that for nonrelativistic calculations.
To speed up publication, the authors of this paper have agreed to not receive the proofs for correction. 相似文献
13.
Hiroshi Tsukuda Masaru Masuzaki Norio Toyosugi Cha Yeol Lee Ritoku Ando Keiichi Kamada Tsuguhiro Watanabe 《International Journal of Infrared and Millimeter Waves》2001,22(8):1147-1162
A linear analysis is described on stabilities driven by an intense relativistic electron beam in an infinitely long, plasma-filled, and dielectric-lined circular waveguide immersed in a finite strength axial magnetic field. A dispersion equation is derived from the cold fluid theory and solved numerically. Beam-plasma instabilities due to interaction between beam modes and the Trivelpiece-Gould modes appear as well as the Cherenkov and the cyclotron Cherenkov instabilities. Parametric researches are carried out varying magnetic field strength, plasma density, and dielectric constant. Effects of a finite magnetic field and plasma filling are discussed in connection with the possibilities of using this system as a microwave radiation source. 相似文献
14.
The linear and nonlinear evolution of a relativistic current sheet of pair (e(+/-)) plasmas is investigated by three-dimensional particle-in-cell simulations. In a Harris configuration, it is obtained that the magnetic energy is fast dissipated by the relativistic drift kink instability (RDKI). However, when a current-aligned magnetic field (the so-called "guide field") is introduced, the RDKI is stabilized by the magnetic tension force and it separates into two obliquely propagating modes, which we call the relativistic drift-kink-tearing instability. These two waves deform the current sheet so that they trigger relativistic magnetic reconnection at a crossover thinning point. Since relativistic reconnection produces a lot of nonthermal particles, the guide field is of critical importance to study the energetics of a relativistic current sheet. 相似文献
15.
Quasilinear equations for relativistic plasmas in external magnetic fields are derived for the case of spatially growing wave turbulence. This generalizes the well-known quasilinear approach to an amplifying relativistic plasma. The equations can be cast in condensed momentum-space diffusive form. The diffusion tensor is given. As a result an inhomogeneity is produced in the space charge distribution giving rise to the development of a second-order field-aligned dc electric field. A general formula for the electrostatic potential is presented, which is specialised to the case of ion-cyclotron turbulence. Here the field points out of the interaction region. 相似文献
16.
N. D. Naumov 《Russian Physics Journal》1981,24(3):270-274
The BBGKY hierarchy of equations for a system of relativistic charged particles is derived. The electromagnetic field is included in the dynamical system by decomposing the transverse part of the field of each particle into oscillators. Self-consistent field equations are obtained for the relativistic plasma, and an expression is also obtained for the correlation function which leads to the Belyaev-Budker collision integral.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 78–82, March, 1981. 相似文献
17.
Greene D. G. S. Shohet J. L. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1973,1(3):108-110
The particles making up a plasma are usually not in equilibrium, and their energies are often relativistic and anisotropically distributed, especially if the plasma is in a d.c. magnetic field. Thus, the usual methods for developing particle distribution functions based on equilibrium conditions are not applicable. A development of a particular anisotropic relativistic distribution function that may describe the particles in a plasma is made. 相似文献
18.
V. S. Sekerzhitskii 《Russian Physics Journal》1997,40(10):978-981
The equation of state of a hydrogen plasma in a magnetic field that is quantizing for charged fermions is obtained within
the framework of the statistical thermodynamics of systems in equilibrium for a model of extremely degenerate, ideal Fermi
gases. Values of the mass density corresponding to nonrelativistic and relativistic electrons are considered, as well as densities
exceeding the threshold for neutronization of cold, magnetized, electron-proton matter.
Brest State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 57–59, October, 1997. 相似文献
19.
20.
O. T. Loza 《Technical Physics》2008,53(11):1479-1484
Cold explosive emission cathodes, in which a plasma serves as an emitting surface, are used to generate relativistic electron
beams with a high current density in a magnetic field. The plasma parameters change within a microsecond, thereby significantly
changing the geometry of the electron beam. This paper is a review of techniques for stabilizing the geometry of microsecond
high-current relativistic electron beams. It is shown that only a transverse-blade explosive emission cathode in a magnetically
insulated diode can generate such beams (500 keV, 3 kA) the current density profile and electron trajectory pitch factor of
which remain constant for a microsecond. 相似文献