[en] Using X-ray pinhole cameras and a crystal spectrograph, we have carefully measured and analysed the radiation composition and spatial distribution of plasmas produced by line-focused laser irradiation on segmented targets. The measured results show that intensities of different satellite lines and resonance lines of aluminium H-like ions are dependent on the laser intensity more strongly than that of He-like ions spectra. In addition, different from Al plasma, Au plasma only emits continuum and the spatial extent of gold LPX radiation remains almost unchanged in the whole range of LPX spectra, which makes the boundary of the spatial distribution of the LPX radiation field very sharp. (author)

[en] The pump depletion is a severe problem which hinders the laser-plasma beat-wave accelerator concept from being practical. Starting with the weak relativistic equation of beat-wave excitation of electron plasma waves, the authors have derived the condition for eliminating the pump depletion in the fame moving with the light pulse for arbitrary pulse shapes. It is shown that the depletion can be eliminated by a phase jump of π at the center of the pump pulse and by the appropriated choice of initial plasma density detuning. The numerical calculation have yielded the dependence of the initial detuning on the pump intensity for square pump pulses, and have supported the methods used in this paper

[en] High-order harmonic generation by relativistic lasers in plasmas with initial velocity distribution has been studied. It is shown that, different from previous models, because of the random thermal motion of electrons, the initially Maxwellian distributed plasma will make the harmonic spectrum more smooth, i.e., it increases the higher-order harmonic power but decreases the lower-order harmonic power. This effect is beneficial for the generation of higher-order harmonics

[en] The resonant absorption of light in cold plasma for linear density profile has been calculated analytically both for long and short scalelengths by calculating the reflectivity from the plasma and vacuum interface. The results in long scalelength case are in agreement with the well-known results but with a higher order in accuracy, and that in short scalelength case are consistent with numerical calculation

[en] Using a simple model, it is shown that because of the relativistic electron-mass variation, the mode-converted electrostatic electric field exhibits hysteresis in the vicinity of critical layer. This hysteretic effect is to increase the resonance absorption of obliquely incident p-polarized light in a way by increasing the large amplitude region of the electrostatic field. When the threshold light intensity for the occurrence of hysteresis is exceeded, the fractional absorption increases drastically above the linear results

[en] The nearly degenerate four-wave mixing in plasma is studied, which is caused by the electron plasma wave excited via the process of stimulated Raman scattering. The third-order nonlinear susceptibilities of the plasma are derived analytically and the condition to satisfy the phase matching is discussed. The couple-wave equations are solved to obtain the phase conjugate reflectivity. The dependence of the reflectivily on the frequency difference between the pump and the probe beam as well as on the interaction length is studied analytically and numerically

[en] The physics of dusty plasmas has been an active branch of plasma science during the past decade. Charged dust exists widely in such diverse environments as space plasmas, laboratory fusion devices, and low-temperature plasma applications in industry. Nevertheless, they exhibit the same or similar characteristics. Dusty plasma is defined as partially or fully ionized plasma consisting of, besides electrons and ions, (usually) negatively charged micro-particles with variable charges. The grains have completely different dynamic behaviours compared with electrons and ions. New phenomena emerge as the result of grain-plasma interactions. This paper describes the basic properties of dusty as well as the history and recent topics of interest in their physics.(authors)

[en] Variational approach is adopted to study the evolution of an ultrashort laser pulse copropagating with an electron plasma wave. By use of the potential well description, the conditions for pulse compression, decompression or stationary state are found, which are results of the competitions between the dispersive diffusion and phase modulation of the pulse by the plasma wave. Results are compared with the numerical calculations of the evolution equation to prove the applicability of the above approximate method

[en] The interactions of two-frequency laser with Langmuir wave in a plasma beat-wave accelerator are calculated. It is shown that the development of the Langmuir wave from initial stage to saturation is closely correlated to the evolution of the three waves involved from phase locking to phase mismatching. The phase difference, describing the extent of three-wave coupling, is therefore of great importance in Langmuir-wave excitation by beating two-frequency laser

[en] The kinetic equation for electron in an intense laser field is derived by transforming the Fokker-Planck equation into the local coordinate system of electron oscillation in the field. The electron-ion collision in circularly-polarized light is calculated, and the electron-electron collision is discussed. The plasma thermo-electric transports are studied for different intensity regions of the circularly-polarized laser field. It is found that, when the electron quiver-velocity in laser field is comparable with its thermal velocity, the thermo-electric transports can be largely decreased as compared to the case without laser field