UMD, College Park, Maryland
Transfer maps for magnetic elements in storage and damping rings can depend sensitively on nonlinear fringe-field and high-order-multipole effects. The inclusion of these effects requires a detailed and realistic model of the interior and fringe magnetic fields, including their high spatial derivatives. A collection of surface fitting methods has been developed for extracting this information accurately from 3-dimensional magnetic field data on a grid, as provided by various 3-dimensional finite element field codes. The virtue of surface methods is that they exactly satisfy the Maxwell equations and are relatively insensitive to numerical noise in the data. These techniques can be used to compute, in Lie-algebraic form, realistic transfer maps for the proposed ILC Damping Ring wigglers. An exactly-soluble but numerically challenging model field is used to provide a rigorous collection of performance benchmarks.
IHEP Beijing, Beijing
The luminosity of BEPCII (the upgrade project of Beijing electron-positron collider) have reached 3.0× 1032 cm-2s-1@1.89GeV in May 2009. In this papaer we'll compare the beam-beam simulation results with the real machine. In the case the single bunch current is lower than 8mA, the simulation concides well with the real. Some phenomenon related to synchro-betatron resonances during machine tuning and simulation is shown. The tune is close to half integer help us increase luminosity, however the detector background increases at the same time. It is believed that the beam-beam dynamic effect result in the drop of the dynamic aperture. We also study the possible luminosity contribution from the crab waist scheme in BEPCII.
Northern Illinois University, DeKalb, Illinois
When faced with the challenge of the design optimization of a charged particle beam system involving beam-material interactions, a framework is needed that seamlessly integrate the following tasks: 1) high order accurate and efficient beam optics, 2) a suite of codes that model the atomic and nuclear interactions between the beam and matter, and 3) the option to run many different optimization strategies at the code language level with a variety of user-defined objectives. To this end, we developed a framework in COSY Infinity with these characteristics and which can be run in two modes: map mode and a hybrid map-Monte Carlo mode. The code, its applications to the FRIB, and plans involving large-scale computing will be presented.