Study of Laser-Plasma Particle Acceleration( II )

The purpose of the project is to apply the theoretical analysis and numericalsimulation on the study of the dynamical behaviors of interactions between theintense electromagnetic wave and plasma in the relativistic regime. Four majorresearch topics are included:1.Sub-terawatt laser wake-field acceleration: The femtosecond, MeV electronscan be generated in a high repetition rate by introducing sub-terawatt laserpulses into highly dense plasmas. Interactions between the sub-terawatt laserpulse and dense plasma can be simulated and analyzed using the particle-in-cellsimulations. Furthermore, we will establish the gas ionization model of high Z gasand/or design the two-stage gas cell in our simulations to stabilize the electronself-injection and enhance the acceleration efficiency.2.Direct laser acceleration of electron beams: Direct laser acceleration of electronbeams can be achieved by utilizing the axial field of a well-guided, radiallypolarized laser pulse in a density-modulated plasma waveguide. Since afavorable ion-focusing force is provided by the precursor, the transverseproperties of witness bunch can be maintained. Moreover, we will modify thedesign of density-modulated plasma waveguides to achieve an improved thequality of the accelerated electron beam.3.Laser plasma proton/ion acceleration: The energetic protons can be generatedby the interaction between intense laser with a ultrathin solid target. However, thetransition of dominant regimes has not been studied yet. Moreover, we willcombine the near critical density target with the ultrathin (< 10 nm) graphenetarget to seek for a more efficient acceleration mechanism. In this topic, thesimulation model will be developed to investigate the laser plasma proton/ion acceleration.4.The study of helicon plasma: By employing the helicon wave, the high-densityand low electron temperature plasma under a wide range of parameters can bestably generated. Theoretical calculations often assume that various physicalvariables, e.g. the plasma density and temperature, are given a priori and areconstant in time. Our project intends to investigate a temporal behavior of thehelicon plasma system by computing the helicon discharge self-consistently andbridge the gap between theory and the experiment.