ABSTRACT
In both single pass lines and rings, there exist different sections that perform different functions which require different types of lattice modules. Modern accelerators and beam transport lines focus the beam transversely using alternate-gradient focusing, also called strong focusing, which evolves from the so-called weak focusing used in betatrons and early weak focusing synchrotrons. The most common form of strong focusing module is the so-called FODO cell, where two quadrupoles of opposite polarity are separated by drifts or homogeneous dipole magnets. This chapter considers a FODO cell with bending magnets. It aims to study the simplest mirror symmetric achromat, which consists of two bend magnets and a quadrupole in the middle. In the past two decades, the concept of multiple-bend achromat has been conceived of and developed to further reduce dispersion in the bending magnets.
