Trapping and acceleration of hollow electron and positron bunch in a quasi-linear donut wakefield.

We study the acceleration and trapping of both negative and positive charged particles in the quasilinear donut wake (created by a Laguerre Gauss laser pulse). The motion of test charged particles is studied in a two-dimensional wakefield. Once the charged particles are completely trapped in the wakefield, the dynamics will be determined. It is shown that for definite parameters of the problem, a positron bunch could be trapped and accelerated and also well compressed in the first-half bucket of the donut wake. The results also show the possibility of trapping and acceleration of a hollow electron bunch with modified longitudinal and transverse properties. It is proved that electrons could be trapped just as a hollow bunch in the quasi-linear donut wake. [ABSTRACT FROM AUTHOR]