Speaker
Description
Nowadays laser-plasma-based wakefield accelerators are capable to deliver GeV-level femtosecond electron bunches crucial for emerging applications in medicine, industry, and fundamental science. Many of these applications critically require the precise characterization of the accelerated electron bunch as well as the plasma wakefield that largely affects the bunch's quality. Advanced diagnostics of such highly transient, microscopic bunch and field structures, however, remains very challenging. Here we address this challenge with a novel technique we name as \textit{femtosecond ultrarelativistic electron microscopy}, which utilizes a high-energy electron bunch from another laser-plasma accelerator as a probe. This single-shot electron microscopy allows us to characterize the nonlinear plasma wakes, the associated electron bunch and the entire transition from laser wakefield to bunch-driven wakefield with high spatiotemporal resolution. We anticipate that these results will significantly advance the understanding of the complex laser-beam-plasma dynamics and also provide a powerful diagnostic tool for the real-time optimization of plasma accelerators.
