Operation status of the SCSS test accelerator. Continuous saturation of SASE FEL at the wavelength range from 50 to 60 NM

Continuous saturation of SASE lasing at the wavelengths ranging from 50 to 60 nm has been achieved in the SPring-8 compact SASE source (SCSS) test accelerator after machine improvements and fine beam tuning. A pulse-energy of ∼30 μJ with a fluctuation of ∼10 % in STD is routinely obtained at 60 nm. This stable and intense EUV SASE has been offered to user experiments since October 2007. Analysis on the obtained lasing data with the measured electron beam density profile indicates that the normalized slice emittance at the lasing part is ∼0.7 πmm·mrad. This paper reports the machine improvements towards the continuous saturation, current lasing performance as well as the latest analysis result on the electron beam quality. (author)