Mini-β structure for ANKA

ANKA is a 2.5 GeV synchrotron radiation facility, which consists of a 500 MeV injector and 2.5 GeV electron storage ring. The storage ring has a four-fold symmetry with a double DBA-structure. The optics was designed with tune values of (6.85, 3.22) and beam emittance of 9.14 × 10^-8m.rad suitable for x-ray lithography and micro-or nano-fabrications. There are four short drift sections (2.2m) used for injection and rf installations and the four long drift sections (5.6m) are kept for insertion devices. The lattice is studied for insertion of mini β insertion devices in the long drift section keeping the short drift section as high as before. The optics is optimised for -1-2m β in the long drift section with little modifications in that section and rest of the lattice is untouched. The present lattice and the modified lattice keeping sufficient marginal gap for such devices are reported in detail