| Plasma Wakefield Accelerators, by proving to be a promising potential for future table-top accelerators, are at the verge of revolutionizing beam physics. Radiation sources with numerous applications, especially in medical treatments, will benefit greatly from that. High energy physics and particle physics are the main target since Plasma Wakefield Accelerators are proposed to be used as the afterburner in the future electron-positron collider aiming to investigate the super symmetric particles [12]. Although recent experiments have successfully demonstrated Plasma Wakefield Accelerators in the current regime of beams, one must not simply generalize the current experimental results to the future extreme regime of beams due to the different physics phenomena such as ion motion, multiple ionization, etc.;In this thesis, the effect of ion motion in the extreme regime of ultra high intensity, ultra low emittance electron beams in future plasma wakefield accelerators is studied and analyzed. Although ion motion is almost negligible in the current experiments regime, we will show why it will be a serious issue to account for in the future high energy beams. The reason is that it results in a severe emittance growth hence quality degradation of the beam. Therefore, it has been a subject of debate over the past few years whether it is going to be a serious bottleneck for the future's ultra high energy electron beam experiments.;We, however, for the first time, show how the ion motion can be reduced. Emittance preservation is a key element for the realization of the Plasma Wakefield Accelerators. Therefore, in this thesis, we propose and analyze some methods such as introducing matching profiles, shaped plasma density, etc. which can be used to mitigate or reduce the emittance growth, the undesired effect of ion motion. |
