A novel approach for positron injection and acceleration in laser driven plasma wakefield is proposed. A three-staged theoretical model is developed and confirmed through simulations. The proposal using two co-axis propagating beams, a Laguerre-Gaussian beam and a Gaussian beam, to drive wakefields in a preformed plasma volume filled with both electrons and positrons. The bremsstrahlung force is utilized to provide the transverse momenta for positron injection and those positrons can be trapped by the focusing field and then accelerated. The simulation shows that a relatively high-charged, quasi-monoenergetic positrons beams can be achieved. The positrons can be accelerated to more than 200 MeV within 2mm, which is similar to the acceleration of electrons in the same scenario.
|Working group||Laser-driven electron acceleration|