In the BESSY VSR project, the variable bunch length storage ring, two high gradient accelerating structures at 1.5 and 1.75 GHz will be phased such that long and short bunches can be stored simultaneously. The longitudinal stability of the short bunches is investigated taking into account the shielded CSRand a purely inductive impedance. Multi particle tracking studies and numerical solutions o...

Measuring a time interval in the nanoseconds range has opened way to 3-D imaging, where additional information as distance of objects light detection and ranging (LiDAR) or lifetime decay fluorescence-lifetime imaging (FLIM) is added spatial coordinates. One key elements these systems measurement circuit, which encodes into digital words. Nowadays, most demanding applications, especially biolog...

The direct ~recomputation of two-electron integrals! implementation of the gauge-including atomic orbital ~GIAO! and the CSGT ~continuous set of gauge transformations! methods for calculating nuclear magnetic shielding tensors at both the Hartree-Fock and density functional levels of theory are presented. Isotropic C, N, and O magnetic shielding constants for several molecules, including taxol ...

We demonstrate a novel technique for performing aberration-corrected surface metrology within existing wavefront-feedback systems. Our technique uses several phase measurements to calculate phase differences that directly reveal the surface gradients of an object under test, due to orthogonal displacements of that object between measurements. We then apply a least-squares algorithm for surface ...

BESSY-VSR, a scheme where 1.5 ps and 15 ps long bunches (rms) can be stored simultaneously in the BESSY II storage ring has recently been proposed [1]. The strong longitudinal bunch focusing is achieved by superconducting high gradient RF cavities. This paper presents investigations of coupled bunch instabilities driven by HOMs of superconducting multi-cell cavities in BESSY-VSR. Analytical cal...

The interacting lattice gas model is used to simulate fluid flow through an open percolating porous medium with the fluid entering at the source-end and leaving from the opposite end. The shape of the steady-state concentration profile and therefore the gradient field depends on the porosity (p). The root mean square (rms) displacements of fluid and its constituents (tracers) show a drift power...

The performance of conjugate gradient schemes for minimizing unconstrained energy functionals in the context of condensed matter electronic structure calculations is studied. The unconstrained functionals allow a straightforward application of conjugate gradients by removing the explicit orthonormality constraints on the quantum-mechanical wave functions. However, the removal of the constraints...

A scheme where 1.5 ps and 15 ps long bunches (rms) can be stored simultaneously in the BESSY II storage ring has recently been proposed (BESSY [1]). This paper presents simulations of single particle beam dynamics influenced by superconducting cavities used for the strong longitudinal beam focusing. The effect of RF jitter on (very short) bunches is investigated and results are discussed. Furth...

As both resources and applications are becoming more complex, resource management also becomes a more challenging task. For example, scheduling code-coupling applications on federations of clusters such as Grids results in complex resource selection algorithms. The abstractions provided by current Resource Management Systems (RMS)—usually rigid jobs or advance reservations—are insufficient to e...