WEA2WC01
QST, Tokai, Japan
High harmonic generation (HHG) is a well-established technology to produce attosecond pulses in VUV wavelengths. So far HHG sources have been driven by femtosecond solid-state lasers not FELs, because it has been believed that FELs have no ability to provide carrier-envelope-phase (CEP) stabilized few-cycle pulses essential to the HHG. Here, we propose a scheme to CEP stabilized few-cycle pulses from a FEL oscillator. Operated at a mid-infrared wavelength, the proposed method is able to drive a HHG photon source to produce isolated attosecond pulses at photon energies above 1 keV with a repetition > 10 MHz. The FEL-HHG photon source will open a door to full-scale experiments of attosecond X-ray pulses and push ultrafast laser science to the zeptosecond regime [1].
[1] R. Hajima and R. Nagai, Phys. Rev. Lett. 119, 204802 (2017)
THA1WC03
QST, Tokai, Japan
Energy-recover linacs (ERLs) have been developed mainly for high-power free electron lasers and future synchrotron light sources but have advantages in Compton sources as well, because the electron beam of high-average current and small emittance in ERLs contribute directly to generation of high-flux and narrow-bandwidth photons via Compton scattering. For demonstrating feasibility of ERL-based Compton sources, we conducted an experiment at the Compact ERL (cERL), where 7-keV X-ray photons with narrow bandwidth, 0.4% (rms) with an opening angle of 0.14 mrad, were generated by colliding an electron beam of 20 MeV with a laser of 1064 nm wavelength. In this talk, we overview the status of ERL-based Compton sources including relevant accelerator and laser components and discuss future perspectives of ERL-based Compton sources for keV and MeV photons.