Effects of electron temperature on dielectric function and localization of laser beams in underdense collisional plasmas are investigated. Simulation results show that the electron temperature has a strong effect on t...Effects of electron temperature on dielectric function and localization of laser beams in underdense collisional plasmas are investigated. Simulation results show that the electron temperature has a strong effect on the dielectric constant and the laser beam localization. It is observed that due to the influence of the electron temperature, the dielectric function presents some interesting and complicated nonlinear variations, and gives rise to the laser beam lo- calization. Moreover, the amplitudes of the beam width and the beam intensity are subjected to continuously oscillatory variation in the region of localization. In addition, the effects of several parameters on the dielectric function and the beam localization are discussed.展开更多
The propagation of multiple ultraintense femtosecond lasers in underdense plasmas is investigated theoretically and numerically.We find that the energy merging effect between two in-phase seed lasers can be improved b...The propagation of multiple ultraintense femtosecond lasers in underdense plasmas is investigated theoretically and numerically.We find that the energy merging effect between two in-phase seed lasers can be improved by using two obliquely incident guiding lasers whose initial phase isπandπ/2 ahead of the seed laser.Particle-in-cell simulations show that due to the repulsion and energy transfer of the guiding laser,the peak intensity of the merged light is amplified by more than five times compared to the seed laser.The energy conversion efficiency from all incident lasers to the merged light is up to approximately 60%.The results are useful for many applications,including plasma-based optical amplification,charged particle acceleration and extremely intense magnetic field generation.展开更多
We propose a compact scheme to modulate a relativistic electron beam(REB)into three-dimensional(3D)nanoscale bunches by injecting a rarefied REB into an underdense plasma.This scheme self-consistently integrates the l...We propose a compact scheme to modulate a relativistic electron beam(REB)into three-dimensional(3D)nanoscale bunches by injecting a rarefied REB into an underdense plasma.This scheme self-consistently integrates the lateral focusing and axial modulation of the REB in its self-driven plasma wakefield.The REB first expels the plasma electrons in its path to form a wake,where the lateral force of the chargeseparation field compresses it to higher density,so that more plasma electrons are expelled as it propagates.The positive feedback loop is repeated until the REB becomes a thin electron filament of density a hundred times that of the original.As it continues to propagate in the elongated electron-free wake bubble,the axial electric field induces an energy chirp on the electron filament,and longitudinally modulates it into 3D nanoscale bunches by asynchronous envelope oscillations.The excitation conditions of this scheme with respect to the beam and plasma parameters,as well as the spatial scale of the obtained electron bunches,are analyzed analytically and agree well with particle-in-cell simulations.In addition,our radiation simulations show that coherent extreme ultraviolet radiation can be generated with such 3D nanoscale bunches.展开更多
In the laser–plasma interaction,relativistic soliton formation is an interesting nonlinear phenomenon and important light mode convection in plasmas.Here,it is shown by threedimensional particle-in-cell simulations t...In the laser–plasma interaction,relativistic soliton formation is an interesting nonlinear phenomenon and important light mode convection in plasmas.Here,it is shown by threedimensional particle-in-cell simulations that relativistic toroidal solitons,composed of intense light self-consistently trapped in toroidal plasma cavities,can be produced by azimuthallypolarized relativistic laser pulses in a near-critical underdense plasma.展开更多
基金Project supported by the Autonomous Innovation Fund,China (Grant Nos.0109012922 and 0109012926)the Youth Foundation of Department of Education of Hubei Province,China (Grant No.Q20101602)
文摘Effects of electron temperature on dielectric function and localization of laser beams in underdense collisional plasmas are investigated. Simulation results show that the electron temperature has a strong effect on the dielectric constant and the laser beam localization. It is observed that due to the influence of the electron temperature, the dielectric function presents some interesting and complicated nonlinear variations, and gives rise to the laser beam lo- calization. Moreover, the amplitudes of the beam width and the beam intensity are subjected to continuously oscillatory variation in the region of localization. In addition, the effects of several parameters on the dielectric function and the beam localization are discussed.
基金supported by the National Natural Science Foundation of China(Grant Nos.12175310,12275356,12135009 and 12075157)the Natural Science Foundation of Hunan Province(Grant No.2022JJ20042)。
文摘The propagation of multiple ultraintense femtosecond lasers in underdense plasmas is investigated theoretically and numerically.We find that the energy merging effect between two in-phase seed lasers can be improved by using two obliquely incident guiding lasers whose initial phase isπandπ/2 ahead of the seed laser.Particle-in-cell simulations show that due to the repulsion and energy transfer of the guiding laser,the peak intensity of the merged light is amplified by more than five times compared to the seed laser.The energy conversion efficiency from all incident lasers to the merged light is up to approximately 60%.The results are useful for many applications,including plasma-based optical amplification,charged particle acceleration and extremely intense magnetic field generation.
基金supported by the National Key R&D Program of China(Grant No.2024YFA1613400)the National Natural Science Foundation of China(Grant Nos.12475238,12175154,12205201,and 12475248)+5 种基金the Financial Support for Outstanding Talents Training Fund in Shenzhen(Project No.202101)the Shenzhen Science and Technology Program(Grant No.RCYX20221008092851073)the Guangdong Province Key Construction Discipline Scientific Research Capacity Improvement Project(Grant No.2021ZDJS107)the Natural Science Foundation of Guangdong(Grant No.2025A1515012853)the Natural Science Foundation of Top Talent of SZTU(Grant Nos.GDRC202310 and GDRC202423)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2025A1515010791).
文摘We propose a compact scheme to modulate a relativistic electron beam(REB)into three-dimensional(3D)nanoscale bunches by injecting a rarefied REB into an underdense plasma.This scheme self-consistently integrates the lateral focusing and axial modulation of the REB in its self-driven plasma wakefield.The REB first expels the plasma electrons in its path to form a wake,where the lateral force of the chargeseparation field compresses it to higher density,so that more plasma electrons are expelled as it propagates.The positive feedback loop is repeated until the REB becomes a thin electron filament of density a hundred times that of the original.As it continues to propagate in the elongated electron-free wake bubble,the axial electric field induces an energy chirp on the electron filament,and longitudinally modulates it into 3D nanoscale bunches by asynchronous envelope oscillations.The excitation conditions of this scheme with respect to the beam and plasma parameters,as well as the spatial scale of the obtained electron bunches,are analyzed analytically and agree well with particle-in-cell simulations.In addition,our radiation simulations show that coherent extreme ultraviolet radiation can be generated with such 3D nanoscale bunches.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA17040502)。
文摘In the laser–plasma interaction,relativistic soliton formation is an interesting nonlinear phenomenon and important light mode convection in plasmas.Here,it is shown by threedimensional particle-in-cell simulations that relativistic toroidal solitons,composed of intense light self-consistently trapped in toroidal plasma cavities,can be produced by azimuthallypolarized relativistic laser pulses in a near-critical underdense plasma.
