Final Report German Work package K7 Simulation Code Development, Help Desk ESS ID SD015DE

The work package K7 Simulationscode Entwicklung, Helpdesk comprised the further development of the Monte Carlo simulation package VITESS for the simulation of neutron scattering experiments, its use to study general questions related to ESS instrumentation in collaboration with the ESS Data Management and Software Center DMSC in Copenhagen and support for users. The package contains now a visualization of instrument and trajectories, the possibility for numerical optimization of instrument parameters and options for parallelization of the simulation for multi core PCs and for computer clusters. Among other improvements, modules to simulate lenses and true elliptical guides have been written, and the monochromator and the detector module have been improved significantly. The graphical user interface and the treatment of events are more user friendly now. For the ESS project, the performance of different guide geometries were compared, different options for extraction systems and guides without direct line of sight developed and optimized, and the effect of gravity and waviness investigated. The work was executed in collaboration with the DMSC. Most of the results have been published already. Apart from direct support for some users, user support was realized by completing and improving the documentation, updating the internet site, setting up a Facebook account and a new email lis