Modern Approaches to Accelerator Simulation and On-line Control*

The use of modeling programs for accelerator beamline control and commissioning is becoming an accepted practice. For control applications, the goal in using these programs is to correct deviations in the beam measurements or to change the machine parameters. Since these programs are used for operation of the machine, they are a part of the on-line control system. For commissioning, the goal is to find the errors in the machine which cause deviations from the predicted beam measurements. Since these latter programs are needed only occasionally during commissioning of a new beamline or starting up an old one, many of these programs are off-line and not integrated into the control system.