PETRA IV study with non-interleaved sextupole scheme

This study is to use the non-interleaved sextupole scheme to design PETRA IV storage ring, which is an upgrade from PETRA III, toward diffraction-limit synchrotron light source. The lattice is constructed by mixing different types of cells. Double minus identity cell is responsible for the chromaticity correction with non-interleaved sextupoles, while the combined function FODO cells provide straights with small beta functions for undulators. These are the basic building bricks. In addition, two hybrid sections with 10-m long super ID are custom-made to adapt to the configuration of DESY's current cite plan. The beam dynamic behaviors are simulated and discussed.