Wang Zhe-Bin

Thomson scattering process in laser-produced plasmas

We present the evolutions of the electron temperature and plasma expansion velocity with Thomson scattering experiment. The observed time-resolved ion-acoustic image is reproduced by a numerical code which couples the Thomson scattering theory with the output parameters of the one-dimensional hydrocode MEDUSA.

Numerical Simulation of the Thomson Scattering Experiment Performed with 0.351μm Laser-Produced Aluminum Plasmas

The evolutions of the electron temperatures of aluminum plasmas produced with 0.351 ?m laser are simulated by means of one-dimensional hydrodynamic code. The simulations show that the plasma geometry has strong influence on the electron temperatures evolution while the effect of the flux limiter is not so significant. The simulations are in good agreement with the experiments only at some spatial points. A full comparison between the simulations and experiments indicates that the one-dimensional code is not accurate enough to characterize the laser-produced plasmas. A post-processor code based on the hydro code is developed to generate the streak image of the Thomson scattering spectra, which can be directly compared with the experimental data.

Conditions for the Observation of Two Ion-Acoustic Waves via Thomson Scattering

Observation of two ion-acoustic waves via Thomson scattering can provide precise measurements of plasma parameters. The conditions for the observation of two ion-acoustic modes in a two-ion plasma are discussed. The ratio of electron temperature Te to ion temperature Ti is the critical parameter for the presence of two ion-acoustic modes, which should be in the range of 4/ZL{Te/Ti}2AH/ZHAL, where ZL,H are the charge states of light and heavy ions, and AL,H are the atomic numbers of light and heavy ions, respectively. As the temperature ratio varies in this range, the concentration of heavy ions must increase with the ratio Te/Ti so that the two ion-acoustic modes can have the same fluctuation levels.