Control of betatron emission via LWFA using aluminum target

Abstract

The laser wake-field acceleration (LWFA) has been spotlighted as a compact electron accelerator, because of its accelerating gradient being several hundred times higher than conventional RF accelerators. In LWFA, a supersonic gas jet or discharged gas flow in a capillary is typically used as a plasma target, Recently, a plasma plume ablated from a solid target, such as, Teflon, Nylon or Aluminum, using a nano-second or pico-second laser pulse is proposed to maintain high vacuum and possibly operate at high repetition rate. In addition, it was demonstrated that metals, like aluminum, having higher charge states play an important role to increase the electron charge. Compared with the LWFA mechanism using helium or hydrogen gases, the LWFA using metallic targets involves the ionization effects. It boosts more electrons to be injected in a wake cavity, while reduces the acceleration length due to ionization diffraction. As increasing the injected electrons, more dynamic betatron oscillation is observed. For developing the new betatron emitter using LWFA, we suggest a dual-staged LWFA using metallic targets: the first is as a source, an energetic electron bunch, and the second is as a radiator. In this presentation, an overview and a study of the control of the betatron emission via 2D or 3D PIC (Paritlce-in-cell) code simulations are described.