ANL, Argonne, Illinois
As accelerator facilities become more complex and demanding and computational capabilities become ever more powerful, there is the opportunity to develop and apply very large-scale simulations to dramatically increase the speed and effectiveness of many aspects of the design, commissioning, and finally the operational stages of future projects. Next-generation radioactive beam facilities are particularly demanding and stand to benefit greatly from large-scale, integrated simulations of essentially all aspects or components. These demands stem from things like the increased complexity of the facilities that will involve, for example, multiple-charge-state heavy ion acceleration, stringent limits on beam halos and losses from high power beams, thermal problems due to high power densities in targets and beam dumps, and radiological issues associated with component activation and radiation damage. Currently, many of the simulations that are necessary for design optimization are done by different codes, and even separate physics groups, so that the process proceeds iteratively for the different aspects. There is a strong need, for example, to couple the beam dynamics simulation codes with the radiological and shielding codes so that an integrated picture of their interactions emerges seamlessly and trouble spots in the design are identified easily. This integration is especially important in magnetic devices such as heavy ion fragment separators that are subject to radiation and thermal damage. For complex, high-power accelerators there is also the need to fully integrate the control system and beam diagnostics devices to a real-time beam dynamics simulation to keep the tunes optimized without the need for continuous operator feedback. This will most likely require on-line peta-scale computer simulations. The ultimate goal is to optimize performance while increasing the cost-effectiveness and efficiency of both the design and operational stages of future facilities.
Tech-X, Boulder, Colorado
High-energy electron cooling requires co-propagation of relativistic electrons over many meters with the recirculating bunches of an ion collider ring. The expected increase of ion beam luminosity makes such systems a key component for proposed efforts like the RHIC luminosity upgrade* and the FAIR project**. Correctly simulating the dynamical friction of heavy ions, during brief interactions with low-density electron populations, in the presence of arbitrary electric and magnetic fields, requires a molecular dynamics approach that resolves close Coulomb collisions. Effective use of clusters and supercomputers is required to make such computations practical. Previous work*** will be reviewed. Recent algorithmic developments**** and future plans will be emphasized.
* http://www.bnl.gov/cad/ecooling
** http://www.gsi.de/GSI-Future/cdr
*** A. V. Fedotov et al., Phys. Rev. ST/AB (2006), in press.
**** G. I. Bell et al., AIP Conf. Proc. 821 (2006), p. 329.
IRMA, Strasbourg