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
We experimentally investigated some of the mechanical properties of ReB2 under high temperature/pressure(TIP)conditions.High-T experiments(up to 600℃at 1 atm)were carried out in a high-T oven attached to a convention...We experimentally investigated some of the mechanical properties of ReB2 under high temperature/pressure(TIP)conditions.High-T experiments(up to 600℃at 1 atm)were carried out in a high-T oven attached to a conventional x-ray diffractometer whereas high-P experiments(up to about 42 GPa at 25℃)were conducted in a diamond-anvil cell using synchrotron x-ray radiation.High-T data suggest a highly isotropic thermal expansivity whereas high-P data suggest a highly anisotropic compressibility for ReB2.展开更多
The paper systematically describes the theoretical research on Cerenkov effect of REB in optical fibres. The analytical expressions for light generation ,collection efficiency ,electron incident angle .the Cerenkov ra...The paper systematically describes the theoretical research on Cerenkov effect of REB in optical fibres. The analytical expressions for light generation ,collection efficiency ,electron incident angle .the Cerenkov radiation sensitivity of the optical fibre to the current density of the REB stream.and the response of the sensitivity to both electron energy and electron incident angles are given. The typical sensor system for REB measurement is presented. The dynamic range and bandwidth are quantitatively analyzed. The calculation results are illustrated,展开更多
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 National Natural Science Foundation of China under Grant No 40872033the Fundamental Research Funds for the Central Universities.
文摘We experimentally investigated some of the mechanical properties of ReB2 under high temperature/pressure(TIP)conditions.High-T experiments(up to 600℃at 1 atm)were carried out in a high-T oven attached to a conventional x-ray diffractometer whereas high-P experiments(up to about 42 GPa at 25℃)were conducted in a diamond-anvil cell using synchrotron x-ray radiation.High-T data suggest a highly isotropic thermal expansivity whereas high-P data suggest a highly anisotropic compressibility for ReB2.
文摘The paper systematically describes the theoretical research on Cerenkov effect of REB in optical fibres. The analytical expressions for light generation ,collection efficiency ,electron incident angle .the Cerenkov radiation sensitivity of the optical fibre to the current density of the REB stream.and the response of the sensitivity to both electron energy and electron incident angles are given. The typical sensor system for REB measurement is presented. The dynamic range and bandwidth are quantitatively analyzed. The calculation results are illustrated,
