Highly efficientγ-ray generation by 10 PW-class lasers irradiating heavy-ion plasmas

摘要

10 PW-class lasers irradiating overcritical plasmas in the quantum electrodynamics regime promise to generate ultrabrightγ-ray sources in the laboratory.Here using two-dimensional particle-in-cell simulations,we report highly efficientγ-ray generation in the parameter regime of 10 PW-class lasers at an intensity level of 10^(23)W cm^(–2)interaction with heavy-ion plasmas which have large-scale preplasmas.The laser-to-γ-ray(>1 MeV)energy conversion efficiency reaches close to 60%with an above 10^(14)γ-photons/pulse.The averageγ-photon energy is about 14 MeV with the highest photon energy exceeding 1 GeV.The high-energyγ-photons are mainly directed in the forward direction.We also find that plane target geometry is efficient enough for high powerγ-ray radiation,which is beneficial for easing the difficulty of complex target manufacturing and alignment in experiments.