Monte-Carlo Simulation On The Scattering Of MeV Electron Beams In Dense Plasma

Electron beams accelerated by laser wakefield can reach high quality. In view of the advantages such as small size, quasi-monoenergetic property, good collimation and short duration, high quality beams have broad application prospects. Nowadays, electron beam diagnostics is becoming one of leading technologies in fields of interaction of ultrashort, intense laser pulses, and target materials. The investigation on electron beam diagnostics is significant for high energy density physics based on the laser technology and the research of inertial confinement fusion. On the one hand, the information of the plasma, such as the areal density and the density distribution of internal situation, could be obtained by the active diagnosis of high-quality electron beam. On the other hand, the electron beam can be used to probe the electric field and magnetic field of the interaction of laser pulses and plasmas. For the diagnosis of hot and dense plasmas, the diagnosis of high-quality electron beam is investigated by numerical simulations.Electron scattering in plasma targets is simulated by a self-developed Monte-Carlo (MC) program. The physical process of electron motion in plasmas is complicated. This code is based on multiple scattering theory and the continuous slowing down model is adopted. The exact stopping power of hot electron in fusion plasmas and relativistic differential cross section are also included in the MC code. Therefore, we can obtain the tracks of energetic electron beam passing through the plasma region and the flux density distribution of electron beams on the centerline of the detector.Based on the simulation of Monte Carlo code, the radiography of MeV electron beam on hot and dense plasma target is investigated. The transport of electron beam in plasmas and the properties of electron beams after transmission are also researched. The results show that the angular width (O) of flux density distribution curve is related to the density-depth product, the areal density (pR). However, the temperature of the plasma target has little impact on the flux density because of scattering of electrons in plasma. By analyzing and fitting, a relationship between scattering angular widths and areal densities of plasma targets is given as:pR ∝ Φ2. In addition, this paper also explored the application of conical electron beam on projection radiography of plasma target. And on the basis of it, we discuss the influence of the position of detector behind the target and the initial kinetic energy of electron beam on imaging effect. These results indicates high-quality MeV electron beam accelerated by laser wakefield will become a novel diagnosis technology for diagnosis of the areal density and inhomogeneity of fusion plasmas.