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تسجيل مستخدم جديدCharged particle motion and radiation in strong electromagnetic fields
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The dynamics of charged particles in electromagnetic fields is an essential component of understanding the most extreme environments in our Universe. In electromagnetic fields of sufficient magnitude, radiation emission dominates the particle motion and effects of nonlinear quantum electrodynamics (QED) are crucial, which triggers electron-positron pair cascades and counterintuitive particle-trapping phenomena. As a result of recent progress in laser technology, high-power lasers provide a platform to create and probe such fields in the laboratory. With new large-scale laser facilities on the horizon and the prospect of investigating these hitherto unexplored regimes, we review the basic physical processes of radiation reaction and QED in strong fields, how they are treated theoretically and in simulation, the new collective dynamics they unlock, recent experimental progress and plans, as well as possible applications for high-flux particle and radiation sources.
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The Landau-Lifshitz equation provides an efficient way to account for the effects of radiation reaction without acquiring the non-physical solutions typical for the Lorentz-Abraham-Dirac equation. We solve the Landau-Lifshitz equation in its covarian
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Time-centered, hence second-order, methods for integrating the relativistic momentum of charged particles in an electromagnetic field are derived. A new method is found by averaging the momentum before use in the magnetic rotation term, and an implem
entation is presented that differs from the relativistic Boris Push [1] only in the method for calculating the Lorentz factor. This is shown to have the same second-order accuracy in time as that (Boris Push) [1] found by splitting the electric acceleration and magnetic rotation and that [2] found by averaging the velocity in the magnetic rotation term. All three methods are shown to conserve energy when there is no electric field. The Boris method and the current method are shown to be volume-preserving, while the method of [2] and the current method preserve the $vec{E} times vec{B}$ velocity. Thus, of these second-order relativistic momentum integrations, only the integrator introduced here both preserves volume and gives the correct $vec{E} times vec{B}$ velocity. While all methods have error that is second-order in time, they deviate from each other by terms that increase as the motion becomes relativistic. Numerical results show that [2] develops energy errors near resonant orbits of a test problem that neither volume-preserving integrator does. [1] J. Boris, Relativistic plasma simulation-optimization of a hybrid code, in: Proc. Fourth Conf. Num. Sim. Plasmas, Naval Res. Lab, Wash. DC, 1970, pp. 3-67. [2] J.-L. Vay, Simulation of beams or plasmas crossing at relativistic velocity, Physics of Plasmas (1994-present) 15 (5) (2008) 056701.
We study electron motion in electromagnetic (EM) fields in the radiation-dominated regime. It is shown that the electron trajectories become close to some asymptotic trajectories in the strong field limit. The description of the electron dynamics by
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We investigate the properties of quantum radiation produced by a uniformly accelerating charged particle undergoing thermal random motions, which originates from the coupling to the vacuum fluctuations of the electromagnetic field. Because the therma
l random motions are regarded to result from the Unruh effect, this quantum radiation is termed Unruh radiation. The energy flux of Unruh radiation is negative and smaller than that of Larmor radiation by one order in a/m, where a is the constant acceleration and m is the mass of the particle. Thus, the Unruh radiation appears to be a suppression of the classical Larmor radiation. The quantum interference effect plays an important role in this unique signature. The results is consistent with the predictions of a model consisting of a particle coupled to a massless scalar field as well as those of the previous studies on the quantum effect on the Larmor radiation.
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