Fig. 3: Collision of e−/e+ bunch with laser pulse, with and without velocity fields.
From: Broadband coherent XUV light from e−/e+ microbunching in an intense laser pulse

From our point particle simulations: a spectrum radiated onto detector, b bunch at laser pulse peak, c bunch at intermediate time, d bunch at end of simulation. Legend in (d) applies to all plots, Tsim is the simulation duration. The acceleration fields lead to the compression of the bunch, while the velocity fields between e− and e+ stabilize the bunch and maintain its coherence over time.