Electron Beam Probing of Plasma Structures in CO2 Laser Driven Wakefields

Laser wakefield acceleration (LWFA) is a technique being studied for generating compact particle and radiation sources. Electrons are accelerated through high electric fields associated with plasma waves which are excited by a high energy laser. The accelerating forces associated with this scheme can be hundreds of times higher than in conventional accelerators. At Brookhaven National Laboratory’s Accelerator testing facility (ATF), we are exploring LWFA driven by a long CO2 laser pulse. The long-pulse assist to investigate the physics of long-pulse laser and plasma interactions in the mid-IR regime. The plasma structure is excited by a CO2 laser pulse and focused by an off-axis parabolic mirror onto a hydrogen gas jet. The spectral signatures, are detected by observing Forward Collective Thomson Scattering (FCTS) of a separate probe laser pulse. FCTS measures the plasma density variations, while the electron probes will measure the internal fields. In this poster, we present preparations for the experiment with an integrated electron beam probe. This research is important for development of CO2 and electron beam diagnostic techniques, which will be used to conduct future short-pulse CO2 LWFA experiments in the blowout regime at the future AFT II upgraded facility.