Operation of the CLIO accelerator

CLIO (Collaboration for an Infrared Laser at Orsay) is a FEL users facility at LURE Laboratory, Orsay, France. The first laser oscillation has been obtained in January 1992 at 5 μm wavelength with an electron beam of 40 MeV from a S-band linac. The first user experiment was performed in April at a wavelength between 7 and 10 μm. Presently, the spectral range spans from 2.5 to 15 μm with beam energies from 50 to 30 MeV. The 2 m undulator, within a 4.8 m long optical cavity, is fed by the S-band linac (3 GHz) designed for 50 MeV ± 20 MeV with a beam current of 0.6 nC charge per bunch of 8 ps duration. We present several measurements of the accelerator performances such as rf stability, beam phase stability, bunch length, beam emittance and energy spectrum with and without laser.