Exploring laser interaction with matters in the quantum electrodynamics regime
With the next-generation laser facilities at the 10-100 petawatt (PW) level, e.g., the EU-funded Extreme Light Infrastructure (ELI) facilities, the physical picture of relativistic laser-plasma interaction found so far with PW scale lasers may not be valid anymore. It enters a new regime, where at least the following distinct features are expected to appear: 1) Dense electron-positron pairs and high energy γ-photons production via quantum electrodynamics (QED) processes; 2) Significant radiation recoil during electron and positron quiver motion in laser fields; 3) As large relativistic electron mass as proton mass, representing a unique plasma state. To fully exploit and understand this highly complex system, we will investigate some fundamental problems including the propagation of ultra-relativistic laser pulses in plasma, their energy dissipation and allocation to energetic particles and photons, and their scaling to laser and target parameters. Understanding of these problems is essential in order to manipulate QED effects for advanced applications, e.g., generation of high peak flux 10GeV protons, modelling of some energetic astrophysical phenomena, etc. This system is compound with collective and kinetic nonlinearities through wave-wave interactions, wave-particle interactions, and new particle generation and annihilation via QED processes. All these will be treated in a self-consistent way by developing an advanced particle-in-cell (PIC) code with QED processes included. The researcher Wei-Min Wang has nearly 10 years of experience in developing PIC codes for various applications. He was awarded the prestigious IUPAP Young Scientist Award in Computational Physics in 2015. The proposed research and training will further bring the researcher to an independent and matured theoretician. The research achievements will provide significant support to European projects associated with the ELI facilities, which will be ready for experiments in the near future.