LBNL, Berkeley, California
Numerical simulations to design high-energy particle accelerators give rise to large-scale ill-conditioned highly indefinite linear systems of equations that are becoming increasingly difficult to solve using either a direct solver or a preconditioned iterative solver alone. In this paper, we describe our current effort to develop a parallel hybrid linear solver that balances the robustness of a direct solver with the efficiency of a preconditioned iterative solver. We demonstrate that our hybrid solver is more robust and efficient than the existing state-of-the-art software to solve these linear systems on a large number of processors.
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock
Demanding applications such as heavy ion fusion, high energy colliders and free electron lasers require the study of beam phenomena like space-charge induced instabilities, emittance growth and halo formation. Numerical simulations for instance with GPT (General Particle Tracer, Pulsar Physics) calculate the mutual Coulomb interactions of the tracked particles *. The direct summation of the forces is rather costly and scales with O(N2). In this paper we investigate a new approach for the efficient calculation of particle-particle interactions: the fast summation by Nonequispaced Fast Fourier Transform (NFFT) **, whereas the NFFT is a generalization of the well known Fast Fourier Transformation (FFT). We describe the algorithm and discuss the performance and accuracy of this method for several particle distributions.
PSI, Villigen
Modern particle tracking codes with their parallel processing capabilities generate data files of the order of 100 Gigabytes. Thus they make very high demands on file formats and post-processing software. H5PartROOT is a versatile and powerful tool addressing this issue. Based on ROOT, CERN's object-oriented data analysis framework developed for the requirements of the LHC era, and the HDF5 hierarchical data format, supplemented by an accelerator-specific interface called H5Part, H5PartROOT combines the statistical and graphical capabilities of ROOT with the versatility and performance of the HDF5 technology suite to meet the needs of the accelerator community. Providing the user with both a graphical user interface (data browser) and a shared library to be used in an interactive or batch ROOT session, H5PartROOT passes on the full power of ROOT without presupposing any knowledge about the intricacies of either ROOT or C++.
