Description
VITESS is an open-source software package for the simulation of neutron instruments and virtual neutron experiments [1]. It allows simulating practically all components used in current neutron scattering instruments and thus simulating all kinds of instruments at existing neutron sources. Instruments are usually first designed using a Graphical User Interface and then optimized using scripts exported from the GUI.
VITESS is under active development. The code has been migrated to a GIT server at Forschungszentrum Jülich (FZJ), where automatic deployment and testing of the program has been enabled to facilitate releases. Testing is realized by dedicated test instruments for each of the main options of each module. This will automatically be executed after each update of the de-veloper branch to keep the program error-free.
The latest version 3.7 contains two new source modules for a better interworking with neutronic simulation software in order to facilitate a combined optimization of source and instruments: KDSource, which increases the number of neutron trajectories using the kernel density estimator method, and SourceAI; which creates a function to define the moderator characteristic using AI. There is also a new module to simulate prisms. The monochromator module allows simulating different monochromator rotations and oscillations now. From this version on, NeXus output is included, handling of the modules from the GUI is improved and the graphics tool GR from FZJ is the standard tool to visualize the monitor output.
The concept and the main features of the VITESS program and the new features of version 3.7 are presented. Finally, an outlook is given to future versions of the package bringing new methodologies especially for digital twins.
References
[1] https://vitess.fz-juelich.de/
