Database for accelerator optics

The Automated Beam Steering and Shaping (ABS) project aims to provide an automatic, generic and reliable software system to ensure the provision of high quality particle beams to users of an accelerator complex. An important component of this project is the access to validated reference data describing the different components installed in the machines, such as monitors as well as the optical and magnetic properties of all magnets. These properties are dependent on the type of particle, on the energy and on the destination of the beam. The data model must therefore be able to represent several particle beams along different trajectories through the same element. Furthermore, the database design must be sufficiently general to allow the description of the elements from a simple dipole to complex multi-coil magnets. For a given operation, the sequence of optics elements with the parameters appropriate to the type of beam must be extracted, suitably formatted and passed as input to a beam optics program. This paper describes the problems encountered during the analysis, the resulting data schema and the software developed for data maintenance. Examples are given for the machines of the CERN PS complex.