Abstract

This paper presents a plasma wakefield acceleration scheme driven by positron beam using the particle-in-cell simulation code in two dimensions. A  positron beam of  charge,  long beam and a transverse size of  is propagated through a  long plasma with initial density of . The particles in the plasma were variably weighted to represent the density ramp. The initial beam density was set to a value greater than the plasma density and the beam propagation followed the magnetically self-focused regime. Results show that as the beam entered the plasma, the plasma wakefield was excited as a result a strong axial electric field gradient (accelerating gradient) slightly in excess of .When the plasma density was increased from to , the accelerating field gradient increased up to . The peak self-focusing magnetic field gradient (B-field) achieved was about . This value was sufficient enough to induce noticeable plasma density perturbation which in turn enhanced the positron beam acceleration.

   Keywords:Positron beam, beam density, plasma density, axial electric field, focusing field, wakefield.