Dispersion and damping rate of Langmuir wave in space plasma with regularized Kappa distributed electrons

The dispersion of Langmuir wave(LW)in an unmagnetized collisionless plasma with regularized Kappa distributed electrons is investigated from the kinetic theory.The frequency and damping rate of LW are analyzed for the parameters relating to the source region of a typeⅢsolar radio burst.It is found that the linear behavior of LW is greatly modified by the suprathermal indexκand the exponential cutoff parameterα.In the regionκ<1.5,the damping rate of LW will be much larger than the one with Maxwellian distributed electrons.Hence,the nonlinear process of LW in lowκregion may exhibit different properties in comparison with the one in largeκregion.

Quark Loop Contribution to the Gluon Damping Rate in Hot QCD

The contribution of the quark loop to the gluon damping rate at zero momentum is calculated using the effective perturbative expansion technique developed by Braaten and Pisarski. It is shown that in the temperature range accessible in the present heavy-ion experiments, the contribution of the quark loop can not be ignored. The numerical results show that the quark loop provides ~n apparent contribution to the gluon damping rate at temperatures of experimental interest.

Convergence Rates to Asymptotic Profile for Solutions of Quasilinear Hyperbolic Equations with Nonlinear Damping

The quasilinear hyperbolic equation with nonlinear damping is considered in this paper,a new asymptotic profile for the solution to the equation is obtained by suitably choosing the initial data of the corresponding parabolic equation,the convergence rates of the new profile are better than that obtained by Nishihara（1997,J.Differential Equations 137,384-395） and H.-J.Zhao（2000,J.Differential Equations 167,467-494）.

Phonon damping in one-dimensional lattices with asymmetric interactions

The symmetry of interparticle interaction plays an important role in determining the energy transport and diffusion behavior of one-dimensional(1D) lattices, not only in the process of hydrodynamics but also in the process of kinetics. In this paper, we study the relaxation properties of phonons in 1D lattices with asymmetric and symmetric interparticle interactions, exemplified by the famous Fermi-Pasta-Ulam-Tsingou model. Asymmetric interparticle interactions(AIIs) lead to larger damping rates of phonons as compared to symmetric ones in the low-temperature limit, and the difference gradually vanishes when the temperature increases. Moreover, in lattices with AIIs, the dependence of the damping rate Γ of phonons still follows a power-law on the wave number q, i.e., Γ ~q^(γ) for small q. In particular, at low temperatures, AIIs result in γ ≈ 1, which is out of the predictions of 3/2 ≤ γ ≤ 2 from various theories. Our results provide insights into understanding the anomalous heat conduction observed in 1D chains and ultra-low phonon heat conduction found in certain solids.

THE INFLUENCE OF PHOTOCHEMICAL PROCESS ON THE ATMOSPHERIC WAVE

The time damping rate of gravity wave in the range of 30-70 km is calaclated in three circumstances:(1)adiabatic process,(2)diabatic process caused by atmospheric cooling,and(3) diabatic process resulting from atmospheric photochemical heating and cooling.The results indicate that the photochemical heating is as important as Newtonian cooling and its contribution to the time damping rate of gravity wave can not he negligible.

HTL resummation in the light cone gauge

The light cone gauge with light cone variables is often used in p QCD calculations in relativistic heavyion collision physics. The Hard Thermal Loops（HTL） resummation is an indispensable technique for hot QCD calculation. It was developed in covariant gauges with conventional Minkowski varaiables; we shall extend this method to the light cone gauge. In the real time formalism, using the Mandelstam-Leibbrant prescription of（n·K）-1,we calculate the transverse and longitudinal components of the gluon HTL self energy, and prove that there are no infrared divergences. With this HTL self energy, we derive the HTL resummed gluon propagator in the light cone gauge. We also calculate the quark HTL self energy and the resummed quark propagator in the light cone gauge and find it is gauge independent. As application examples, we analytically calculate the damping rates of hard quarks and gluons with the HTL resummed gluon propagator in the light cone gauge and showed that they are gauge independent. The final physical results are identical to those computed in covariant gauge, as they should be.

Study of Robinson instabilities with a higher-harmonic cavity for the HLS phase Ⅱ project

In the Phase Ⅱ Project at the Hefei Light Source, a fourth-harmonic ＂Landau＂ cavity will be operated in order to suppress the coupled-bunch instabilities and increase the beam lifetime of the Hefei storage ring. Instabilities limit the utility of the higher-harmonic cavity when the storage ring is operated with a small momentum compaction. Analytical modeling and simulations show that the instabilities result from Robinson mode coupling. In the analytic modeling, we operate an algorithm to consider the Robinson instabilities. To study the evolution of unstable behavior, simulations have been performed in which macroparticles are distributed among the buckets. Both the analytic modeling and simulations agree for passive operation of the harmonic cavity.