THE AMPS MAGNET CONTROL-SYSTEM

The beam of the Medium Energy Accelerator MEA (E(max) < 1 GeV) is injected into the Amsterdam Pulse Stretcher AmPS. The beam in the stretcher ring is controlled by 200 magnets of various kinds: dipoles, quadrupoles, sextupoles and steering magnets. Some of the magnets are controlled by a single power supply, others share their power supply in a family of magnets. The power supplies are part of the distributed control system, and are interfaced by VME modules and BITBUS networks. A special magnet server was created, which enables the operator to perform high level actions on the magnets, such as: cycling, degaussing and wobbling. Also a set of Closed Orbit Correction routines was developed to calculate the theoretical values for the power supplies to maintain a stable beam in the ring. This set also contains routines to calculate physical quantities such as tune, chromaticity, and local distortions (bumps). The library routines obtain their information from the lattice data of the ring. A set of graphical user interfaces (GUIs) was designed to make use of all the capabilities.