Enhanced photon emission and pair production due to heavy ion mass in the interaction of an ultraintense laser with overdense plasmas is explored by particle-in-cell simulation. It is found that plasmas with heavier i...Enhanced photon emission and pair production due to heavy ion mass in the interaction of an ultraintense laser with overdense plasmas is explored by particle-in-cell simulation. It is found that plasmas with heavier ion mass can excite a higher and broader electrostatic field, which causes the enhancement of backward photon emission. The pair yields are then enhanced due to the increase of backwards photons colliding with the incoming laser pulse. By examining the density evolution and angle distribution of each particle species, the origin of pair yield enhancement is clarified.展开更多
Since its inception,the full Lagrangian meshless smoothed particle hydrodynamics(SPH)has experienced a tremendous enhancement in methodology and impacted a range of multi-physics applications in science and engineerin...Since its inception,the full Lagrangian meshless smoothed particle hydrodynamics(SPH)has experienced a tremendous enhancement in methodology and impacted a range of multi-physics applications in science and engineering.This review presents a concise survey on latest developments and achievements of the SPH method,including:(1)Brief review of theory and fundamental with kernel corrections,(2)The Riemann-based SPH method with dissipation limiting and high-order data reconstruction by using MUSCL,WENO and MOOD schemes,(3)Particle neighbor searching with particle sorting and efficient dual-criteria time stepping schemes,(4)Total Lagrangian formulation with stablized,dynamics relaxation and hourglass control schemes,(5)Fluid-structure interaction scheme with interface treatments and multi-resolution discretizations,(6)Novel applications of particle relaxation in SPH methodology for mesh and particle generations.Last but not least,benchmark tests for validating computational accuracy,convergence,robustness and efficiency are also supplied accordingly.展开更多
This paper proposes a method to create 3D fusion images,such as volume–volume,volume–surface,and surface–surface fusion.Our method is based on the particle-based rendering,which uses tiny particles as rendering pri...This paper proposes a method to create 3D fusion images,such as volume–volume,volume–surface,and surface–surface fusion.Our method is based on the particle-based rendering,which uses tiny particles as rendering primitives.The method can create natural and comprehensible 3D fusion images simply by merging particles prepared for each element to be fused.Moreover,the method does not require particle sorting along the line of sight to realize right depth feel.We apply our method to realize comprehensible visualization of medical volume data.展开更多
基金supported by National Natural Science Foundation of China (NSFC) under Grant No. 11475026
文摘Enhanced photon emission and pair production due to heavy ion mass in the interaction of an ultraintense laser with overdense plasmas is explored by particle-in-cell simulation. It is found that plasmas with heavier ion mass can excite a higher and broader electrostatic field, which causes the enhancement of backward photon emission. The pair yields are then enhanced due to the increase of backwards photons colliding with the incoming laser pulse. By examining the density evolution and angle distribution of each particle species, the origin of pair yield enhancement is clarified.
基金This work was supported by the Deutsche Forschungsgemeinschaft(DFG)(Grant No.HU1527/12-4)。
文摘Since its inception,the full Lagrangian meshless smoothed particle hydrodynamics(SPH)has experienced a tremendous enhancement in methodology and impacted a range of multi-physics applications in science and engineering.This review presents a concise survey on latest developments and achievements of the SPH method,including:(1)Brief review of theory and fundamental with kernel corrections,(2)The Riemann-based SPH method with dissipation limiting and high-order data reconstruction by using MUSCL,WENO and MOOD schemes,(3)Particle neighbor searching with particle sorting and efficient dual-criteria time stepping schemes,(4)Total Lagrangian formulation with stablized,dynamics relaxation and hourglass control schemes,(5)Fluid-structure interaction scheme with interface treatments and multi-resolution discretizations,(6)Novel applications of particle relaxation in SPH methodology for mesh and particle generations.Last but not least,benchmark tests for validating computational accuracy,convergence,robustness and efficiency are also supplied accordingly.
文摘This paper proposes a method to create 3D fusion images,such as volume–volume,volume–surface,and surface–surface fusion.Our method is based on the particle-based rendering,which uses tiny particles as rendering primitives.The method can create natural and comprehensible 3D fusion images simply by merging particles prepared for each element to be fused.Moreover,the method does not require particle sorting along the line of sight to realize right depth feel.We apply our method to realize comprehensible visualization of medical volume data.
