2025/08/15 by Sun, Ting, Dou, Zhen-Ke, Huang, Ya-Qing +3
#Accelerator Physics (physics.acc-ph) #FOS: Physical sciences #Plasma Physics (physics.plasm-ph)
paper · doi:10.48550/arxiv.2508.11148
Plasma-based acceleration of positrons attracts extensive interests due to the ultrahigh accelerating gradient and ultrashort duration, while generating wakefield positron beam by the inherent injection is still a great challenge. Here, we put forward a superponderomotive injection method of positrons in the blowout regime of laser wakefield acceleration. In this method, transverse laser fields facilitate the trapping of positrons into the laser-modulated longitudinal wakefield which dominates the subsequent energy gaining, that is distinct from the electrostatic induced superponderomotive electrons. Particle-in-cell simulations demonstrate that this method can be implemented by the collision between a donut wake and a pair jet, resulting in the multi-cycle positron beam with hundreds of pC charge and brightness of 1013~\rmAm-2. Such a collisional setup is available in the current laser-plasma experiments, and the generated positron beam is favorable for developing next generation of electron-positron collider, modeling the laboratory astrophysics and performing the ultrafast material diagnostics research.