Realizing Optical Free-Electron Lasers with Traveling-Wave Thomson-Scattering


Realizing Optical Free-Electron Lasers with Traveling-Wave Thomson-Scattering

Steiniger, K.; Bussmann, M.; Debus, A.; Irman, A.; Jochmann, A.; Pausch, R.; Röser, F.; Schramm, U.; Sauerbrey, R.

Optical free-electron lasers (OFELs) from the EUV to X-ray range can be realized in Traveling-Wave Thomson-Scattering (TWTS)[1,2] by utilizing pulse-front tilted high-power laser pulses as optical undulators.
The interaction distances required to induce microbunching to the electron beam for coherent radiation emission are realized in TWTS with a combination of side-scattering and a tilt of the laser pulse-front, as depicted in fig. 1. In the side-scattering geometry the electron beam and laser pulse directions of motion enclose the interaction angle. The tilt of the laser pulse-front by half of the interaction angle then ensures continuous overlap of electrons and laser while both are propagating in different directions. In this way, the interaction distances realized in TWTS are only limited by the transverse size of the laser and thus by the available laser power and size of available optics.
Our fully analytic theory of TWTS OFELs provides scaling laws for the electron and laser pulse quality requirements for OFEL operation. We show that TWTS OFELs can be realized with state-of-the-art technology in electron accelerators and laser systems if the presented scheme for dispersion control is applied. Thereby the variability of TWTS with respect to the interaction angle is used to control the electron and laser beam quality requirements. Especially the sub-μm transv. emittance beams from laser wakefield accelerators with energy spreads in the percent level can be used for the realization of all-optical FELs with acceleration and interaction distances in the centimeter range. An outlook on 3D simulations of TWTS OFELs using the particle in cell code PIConGPU is given.

Keywords: Thomson-scattering; X-ray; FEL; PIConGPU

  • Invited lecture (Conferences)
    Laser Plasma Acceleration Workshop 2015, 11.-15.05.2015, Guadeloupe, France

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Publ.-Id: 21978