Project for generation of femtosecond X-ray beams from the DUKE storage ring

We propose to develop a CW X-ray femtosecond (fsec) source at 1.2 GeV Duke storage ring with the X-ray energy tuneable from 1.4 keV to 75 keV, the average flux from 10/sup 12/ to 10/sup 13/ ph/sec, and the average spectral brightness up to 0.510/sup 15/ ph/sec/mm/sup 2//mrad/sup 2//0.1%BW. A novel RF system with strong longitudinal focusing will compress and to sustain the electron bunches circulating in the ring to a RMS duration from 15 to 85 fsec. The CW fsec electron bunches will generate the Compton hard-X-ray beams and the photon beams from the existing light sources ranging form IR to VUV. Beams of all colours will be synchronised by the e-beam without jitter, making this configuration perfectly suites for pump-probe experiments. The proposed approach promises to outperform the popular "slicing technique" by at least three orders of magnitude. Duke's approach can be implemented at existing light source facilities at modest cost.