Theoretical And Numerical Studies Of Interaction Between Ultra-short Intense Laser Pulses With Plasma

Under the stimulation of the rapid development of laser technology, weachieved ultrashort laser pulses, and laser fusion has become the focus of the science.The research of laser plasma instabilities and X-ray attosecond pulses have greatsignificance for the laser fusion.We investigate the instabilities of stimulated Raman scattering, which wasgenerated by the circular polarization laser light with the810nm wavelength and0.81ps duration interacting with one-dimensional inhomogeneous plasma.Manlry-Rowe relations and parametric instabilities of one-dimensional dispersionrelation were used. Using the one-dimensional particle-in-cell code, we analysis thestimulated Raman scattering in the different location of the target. In the same time,we also discussed the influence of laser intensity, electronics and plasma density andthe scale of the target on the Forward and Backward Raman scattering. Comparingwith Forward Raman scattering and lateral Raman scatterings, Backward Ramanscattering’s space growth was the greatest. As the laser spread to300(the scale ofplasma is about8000), the growth of Backward Raman scattering was completed,but the Forward Raman scattering was still increasing. Laser intensity and plasmadensity influenced the Raman scattering greatly. For the same plasma target, thehigher laser intensity was, the more obvious of the instability was, and the largerarea of the instability was, until the continuous spectrum was produced. For the samelaser intensity, the higher plasma density was, the more obvious of the instability was,and the larger area of the instability was, until the continuous spectrum wasproduced. Stokes and anti-Stokes peaks were discrete peaks, and the peaks were verysharp and high. For the scheme of X-ray attosecond pulses generated by the interaction ofultra-short and intense laser pulses with two solid foils target, which is simulated andcalculated in theory by one-dimensional particle numerical simulation. The focus ofthis article is the impact of the intensity of the laser pulse and the target thickness onX-ray attosecond pulses. The results show that within certain rang of laser intensity,the frequencies of X-ray increased with the increasing of laser pulse intensity. Underoptimum conditions of the driving laser intensity and the source-target thickness,The greater frequency of the probe light, the shorter wavelength and narrower widthof the X-ray attosecond pulse was generated. the highest center frequency of theX-ray we have got, which was about1.881018Hz. But the higher energy andgreater the frequency of the hard X-ray are still to be studied.