The super-ACO free electron laser source in the UV and its applications

Abstract

Free electron lasers (FELs) are new sources of tuneable coherent radiation, based on the interaction of a relativistic electron beam with a permanent magnetic field. The Super-ACO FEL operates in the UV (down to 300 nm ) at 800 MeV , the nominal energy of the electron beam, with a high repetition rate (8 MHz) . It presents a high average extracted power (up to 300 mW ), short pulses (15–50 ps FWHM) and small bandwidth (3×10 −2 nm) . Taking advantage of these characteristics, we demonstrated for the first time the possibility of using a storage ring FEL as a coherent source of radiation for scientific applications. In particular, the tuneable Super-ACO FEL source, combined with synchrotron radiation covering the X-ray to infra-red range, is a unique tool for the time-dependent studies of excited states. Such analysis benefits from the natural synchronisation of both sources at a high repetition rate, their mutual tunability, high intensity and coherence. Several experimental set-ups are now under operation.