Numerical Studies Of Attosecond X-ray Sources Generated By Interaction Between Ultra-short Ultra-intense Laser Pulses With Nano Plasma Foils

In the field of plasma physics, the interaction between ultra-short ultra-intense laser pulses with nano plasma foils plays an important research value on accelerating high-energy particles and generating high-quality high-brightness attosecond X-ray sources. In this thesis, by using one-dimensional particle-in-cell numerical simulation, frequency tunable quasi-monochromatic attosecond X-ray pulses generated by the interaction between ultra-short ultra-intense laser pulses with nano plasma foils is studied.First of all, coherent Thomson backscattering model and single electron model of the interaction between laser pulses with nano plasma foils is described in detail, then we point out the key to obtaining quasi-monochromatic attosecond X-ray sources.Secondly, by using one-dimensional particle-in-cell numerical simulation, we have studied the generation of coherent relativistic electron sheets driven by different polarized laser pulses. The results show that the relativistic electron sheets’ energy evolution has nothing to do with the initial carrier envelope phase when the driving laser pulses is circular polarization, due to the pondermotive force of the circular polarized driving laser pulses oscillates only once. Furthermore, the relativistic electron sheets’energy dispersive in the process of acceleration is smaller than linear polarization, spatial distribution is narrower too. By increasing the driving laser pulses’ width, we get the results that fewer cycle pulses have stronger pondermotive force at the same laser intensity, which is more suitable for the generation of the coherent relativistic electron sheets.Finally, let coherent relativistic electron sheets generated from nano plasma foils driven by a circular polarized laser pulses interacts with a signal pulses. By changing the distance of the producing foils and the reflecting foils, the coherent relativistic electron sheets’ energy can be adjusted arbitrarily. Then let the signal pulses impinges on the coherent relativistic electron sheets and Thomson backscattering occurs, frequency tunable quasi-monochromatic attosecond X-ray sources can be obtained. Furthermore, the effect of the producing foil’s initial density and initial thickness is studied, the results show that reduce the producing foil’s initial density and initial thickness appropriately can keep the attosecond X-ray sources’ quasi-monchromaticity well. The intensity of the attosecond X-ray sources will be stronger, for the spatial distribution of the relativistic electron sheets is smaller.