Large per-shot numbers of photons from Thomson scattering with variable energy and bandwidth

Finite bandwidth x-ray pulses generated in the interaction of a bunch of relativistic electrons with a high-intensity, ultra-short laser pulse are interesting for a variety of experiments that do not require the very small bandwidth delivered by x-ray free electron lasers.
We present a new scheme for Thomson scattering in which we use a grating setup similar to that found in a grating compressor as used in high-power short-pulse laser systems. The gratings are used to introduce a tilt of the laser pulse front and to compensate for dispersion and other unwanted effects on the laser pulse interacting with the electrons. Electron and laser beam are brought in overlap in a side scattering geometry for which the laser pulse is elongated in one spatial direction using an elliptical mirror so that the region of overlap between laser pulse and electron bunch is greatly increased compared to a simple head-on scenario for Thomson scattering..
This increase in size allows to increase the laser pulse energy while keeping the local intensity of the light seen by the electrons low, thus effectively increasing the number of scattered photons by up to three orders of magnitude.
By increasing the length of the overlap region one can decrease the bandwidth of the scattered x-ray photons for a given laser pulse energy, while changing the pulse front tilt angle allows to vary the wavelength of the x-ray photons without changing the electron beam energy.