• K.A. Brown, L. A. Ahrens, J. Beebe-Wang, J. Morris, S. Nemesure, G. Robert-Demolaize, T. Satogata, V. Schoefer, S. Tepikian
  BNL, Upton, Long Island, New York

The on-line models for RHIC and the RHIC pre-injectors (the AGS and the AGS Booster) can be thought of as containing our best collective knowledge of these accelerators. As we improve these on-line models we are building the framework to have a sophisticated model-based controls system. Currently the RHIC on-line model is an integral part of the controls system, providing the interface for tune control, chromaticity control, and non-linear chromaticity control. What we will discuss in this paper is our vision of the future of the on-line model environment for RHIC and the RHIC pre-injectors. Although primarily these on-line models are used as Courant-Snyder parameter calculators using live machine settings, we envision expanding these environments to encompass many other problem domains. We will also discuss the importance of the modeling infrastructure and organization as well as interfacing to controls, power supply, and magnetic measurement infrastructure and organizations. The model engines themselves will be discussed and our own evolution toward incorporating more sophisticated simulation filters, such as PTC and UAL, into the on-line model infrastructure.

• V. Schoefer, L. A. Ahrens, K.A. Brown, A.U. Luccio, W.W. MacKay, T. Roser
  BNL, Upton, Long Island, New York

In order to preserve polarization during polarized proton operation for RHIC, two partial Siberian Snakes are employed in the AGS, where a number of strong spin depolarization resonances must be crossed. These Snakes cause a significant distortion to the injection lattice of the AGS and must be included in the on-line model. In this report we discuss the problem of modeling Snakes as optical elements, particularly as madx elements, and present results comparing measurements to the AGS on-line model.