Speaker
Description
Terawatt XFELs represent the frontier in further development of x-ray sources and require high current densities with strong transverse focusing. In this paper, we investigate the implications/potentialities of TW XFELs on the generation of harmonics at still shorter wavelengths and higher photon energies. The simulations indicate that significant power levels are possible at high harmonics and that these XFELs can be an important coherent source of hard x-rays through the gamma ray spectrum. For this purpose, we use the MINERVA code which self-consistently includes harmonic generation. Both helical and planar undulators are discussed for fundamental at 1.5 Å and we study the associated harmonic generation. Tapered undulators are needed to reach TW fundamental powers, but the taper does not enhance the harmonics. Nevertheless, the harmonics reach substantial powers. Simulations indicate that, for the parameters under consideration, peak powers of the order of 180 MW are possible at the 5th harmonic with a photon energy of about 41 keV and still higher harmonics may be generated at substantial powers. Such high harmonic powers are certain to enable a host of enhanced applications.
Funding Agency
US DOE contract DE-SC0024397
