Two-color experiments combining the UV storage ring free-electron laser and the SA5 IR beamline at Super-ACO

摘要

Abstract: The UV-storage ring Free Electron Laser (FEL) operating at Super-ACO is a tunable, coherent and intense (up to 300 mW) photon source in the near-UV range (300 - 350 nm). Besides, it has the unique feature to be synchronized in a one-to-one shot ratio with the Synchrotron Radiation (SR) at the high repetition rate of 8.32 MHz. This FEL $PLU SR combination appears to be very powerful for the performance of pump- probe time-resolved and/or frequency-resolved experiments on the sub-ns and ns time-scales. In particular, there is a strong scientific case for the combination of the recently- commissioned SA5 Infra-Red Synchrotron Radiation beamline with the UV-FEL, for the performance of transient IR- absorption spectroscopy on FEL-excited samples with a Fourier-transform spectrometer coupled with a microscope allowing high spectral and spatial resolution. The principle and interest of the two-color combination altogether with the description of both the FEL and the SA5 IR beamline are presented. The first synchronization signal between the IR and the UV beams is shown. The correct spatial overlap between the UV (FEL) and the IR (SR) photon beams is demonstrated by monitoring via IR-spectro-microscopy the time evolution of a single mineral particulate (kaolinite) under UV-FEL irradiation.!27