Caustic structures in the spectrum of x-ray Compton scattering off electrons driven by a short intense laser pulse

Understand

We study the Compton scattering of x-rays off electrons that are driven by a relativistically intense short optical laser pulse.

• The frequency spectrum of the laser-assisted Compton radiation shows a broad plateau in the vicinity of the laser-free Compton line due to a nonlinear mixing between x-ray and laser photons.
• Special emphasis is placed on how the shape of the short assisting laser pulse affects the spectrum of the scattered x-rays.
• In particular, we observe sharp peak structures in the plateau region, whose number and locations are highly sensitive to the laser pulse shape.