Generation Of High-quality Attosecond Electron Bunches From Plasma Driven By Ultrashort Ultraintense Laser Pulse

With the rapid development of laser technology,generation of attosecond electron bunches from ultraintense laser pulse interacting with plasma,and their applications in novel radiation sources have attracted significant interest in past decades.The generated attosecond bunches have unique beam properties,such as high density,ultrashort duration,low emittance and low energy spread.These bunches,as a plasma mirror,can be used to control relativistic laser pulses,and have potential values in laser-driven fusion physics.Our work is based on the research by Prof.Yanyun Ma,and two schemes are proposed to produce high-quality and tunable attosecond electron bunches.The thesis composes the following four parts:In the first part,we introduce the development of particle accelerators,especially for the advantages and situation of the laser-plasma accelerator.Then the characteristics of the laser-plasma interaction are summarized,including the concept of the ponderomotive force,and their applicative fields.In the end,we introduce the theory of particle-in-cell simulation and its development.In the second part,we introduce that the generation schemes of single attosecond electron bunch,including the laser direct acceleration and the laser foil interaction,and analyse their technical difficulties.For attosecond electron trains,we summarize the theories and numerical results of the laser interacting with small droplets and long slice targets.Besides,it is found that the laser-driven wake-field structure can modify the injected attosecond electron bunch to generate attosecond electron trains.In the third part,with the help of 2D3V code LAPINE,we investigate the generation of a single quasi-monoenergetic attosecond electron bunch from the laser plasma interaction,and discuss the influence of laser and target on beam quality.It is shown that the electrons around the target surfaces can be accelerated efficiently,with a quasi-monoenergetic spectrum.The peak energy reaches about 90 MeV at a laser intensity of?1021 W/cm2.In the fourth part,a scheme to generate the relativistic electron mirror from plasma gas target is proposed.We find that an electron flying mirror of density?1.5nc can be achieved by a circularly-polarized laser pulse irradiating a underdense plasma sheet with the density of 0.01nc,where nc is the critical density of plasma for the laser wavelength ?0.The size of the generated electron bunches keeps almost constant during the interaction.Facing the actual requirements,we also perform the parametric investigation on the beam quality,and the results are very meaningful for the future experiments of the generation of the relativistic plasma mirror.