Commissioning progress of the femtoslicing at SOLEIL

The femtoslicing project at SOLEIL is currently under commissioning. It will enable to serve several beamlines with 100 fs FWHM long pulses of soft and hard X-rays with reasonable flux and with a 1 kHz repetition rate. It is based on the interaction of a femtosecond Ti:Sa laser with electrons circulating in the magnetic field of a modulator wiggler, that provides the electron beam energy modulation on the length scale of the laser pulse. The optimization of the interaction is performed using two dedicated diagnostics stations. The first one, operating in the Infra-Red (IR) is installed in the tunnel and allows the adjustment of the temporal, spectral and spatial overlap between the laser and the electron beam. The second one, located in the IR-THz AILES beamline, measures the intensity of the terahertz (THz) radiation emitted by the local dip structure produced in the core electron beam after interaction. This second setup provides refined optimization of the interaction. This paper describes the layout of these diagnostics and gives first results and characterization of the slicing experiment at SOLEIL.