The first half of this book discusses the linear and nonlinear optimization of a storage ring lattice for SESAME project. Many aspects are used to get the optimum solution. The outcome of this study is a highly compact lattice which offers 41 % of the 133.2 m ring circumference as straight sections dedicated for Insertion Devices and other needs. The importance of including the vacuum chamber limitations in the nonlinear calculations is proved in SESAME case. This is supported by the results of Frequency Map Analysis. In the second half of the book a low momentum compaction factor optics is proposed for the storage ring of Synchrotron SOLEIL in France. This optics has the advantage of keeping the horizontal emittance small. This optics has been successfully applied to SOLEIL storage ring, and the Coherent Synchrotron Radiation in the THz region has been observed on an Infra Red beamline. During these experiments three beams have been observed rotating simultaneously in the storage ring. This phenomenon, which was the first seen in storage ring at that time, is explained and simulated by expanding the longitudinal dynamics to third order.