Parallelized Vlasov-Fokker-Planck solver for desktop personal computers

Abstract

The numerical solution of the Vlasov-Fokker-Planck equation is a well established method to simulate the dynamics, including the self-interaction with its own wake field, of an electron bunch in a storage ring. In this paper we present Inovesa, a modularly extensible program that uses OpenCL to massively parallelize the computation. It allows a standard desktop PC to work with appropriate accuracy and yield reliable results within minutes. We provide numerical stability-studies over a wide parameter range and compare our numerical findings to known results. Simulation results for the case of coherent synchrotron radiation will be compared to measurements that probe the effects of the micro-bunching instability occurring in the short bunch operation at ANKA. It will be shown that the impedance model based on the shielding effect of two parallel plates can not only describe the instability threshold, but also the presence of multiple regimes that show differences in the emission of coherent synchrotron radiation.

Synchronous detection of longitudinal and transverse bunch signals at a storage ring

“…At this point, the charge density inside the bunch is high enough and the bunch becomes unstable. Numerical simulations of the longitudinal phase space using the Vlasov-Fokker-Planck solver Inovesa [40] showed, that at this point the amplitude of the sub-structures starts to grow rapidly [41].…”

Continuous bunch-by-bunch spectroscopic investigation of the microbunching instability

“…However, they fail for spikes and, especially, many small sub-structures as they happen for bunch charges above the MBI threshold being investigated here. Therefore, we chose the approach to use the Vlasov-Fokker-Planck solver Inovesa [34] to simulate the phase space, extract the emitted power spectrum and compare this to our spectroscopic measurements. A comparison of the four spectral bands gives much more evidence about the validity of the simulation than the previous comparison to a single detector which integrates all the emitted radiation.…”

High throughput data streaming of individual longitudinal electron bunch profiles

“…Because these microstructures produce strong THz radiation bursts with an intensity more than 5 orders of magnitude higher than incoherent synchrotron radiation [2] potentially leading to e.g. applications in non-linear spectroscopy, this process is subject to intense investigations [3][4][5][6][7][8][9][10][11][12]. Although far-field CSR measurements are a useful approach, additional methods exploring the phase space more directly are desirable in order to tighter connect * stefan.funkner@kit.edu † Present address:PSI, Villigen, Switzerland ‡ Present address:DESY, Hamburg, Germany theory and experiment.…”