199 / 2023-04-15 19:08:06

High energy density $e^{+}e^{-}\gamma$-photon plasma generation by laser-electron beam collisions under the extreme light field

极端光下的基础物理学 > 极端光下的基础物理学-海报

An all-optical scheme for generating $e^{+}e^{-}\gamma$-photon plasma is presented and verified using a full three-dimensional particle-in-cell containing a QED module. Our 3D-PIC simulation results show that the yield of high-energy density $e^{+}e^{-}\gamma$-photon plasma is up to $10^{9}$, and the duration is about 20 laser cycles. The $e^{+}e^{-}\gamma$-photon plasma consists of three main stages: In the first stage, electrons are first accelerated by the laser and trapped in the plasma channel through the radiation reaction effect. It is due to the electron-radiating photons that generate a strong radiation reaction force. At the same time, the self-generated magnetic field in the channel further enhances the confinement of the electron beam. When the captured electrons collide with the contra-propagating laser in the second stage, the excitation of γ photons is instantly enhanced in both number and energy. The high-energy gamma photons collide with the scattered laser to enter the third stage. In the third stage, a nonlinear Breit-Wheeler process is triggered by the collision of gamma photons and scattered lasers, resulting in a high energy density of electron-positron pairs. In addition, by changing the thickness of the laser and plasma targets, we find that the generation of $e^{+}e^{-}\gamma$-photon plasma increases with the intensity of the driving laser and the scattering laser. The e$e^{+}e^{-}\gamma$-photon plasma is the most efficient to produce in a specific target density range.