MINI-BETA LATTICE FOR THE FEMTO-SECOND X-RAY SOURCE AT THE ALS*

After generating the first femto-second X-ray pulses at the Advanced Light Source (ALS), it becomes critical to im-prove the flux of this femto-second source for user exper-iments. A narrow-gap in-vacuum undulator has been pro-posed to be installed in one of the ALS straight sections. To realize the optimal performance of this undulator, a straight section lattice with a mini vertical beta function has been designed. Separation of electrons has been achieved by generating a sizable vertical dispersion via a local disper-sion bump and a closed orbit bump. Particle tracking study shows that the modified ALS lattice for the femto-second x-ray source has an adequate dynamic aperture.