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Department Dynamics and Transport in Quantum Materials

vitess logo 320x135 VITESS Logo

Virtual Instrumentation Tool for Neutron Scattering at Pulsed and Continuous Sources

Welcome to the former homepage of the simulation program 'VITESS' (Virtual Instrumentation Tool for the European Spallation Source). The current homepage is hosted by FZ Jülich.

VITESS is a tool for simulation of neutron scattering instruments and experiments at pulsed and continuous sources. Using VITESS, you can simulate a large variety of instruments at all major current and future neutron sources, including the European Spallation Source, which is currently being designed. VITESS is supported by a graphical user interface (GUI), making it simple for you to compose your instrument and run simulations. You can use VITESS on a Windows, Linux or Macintosh computer. Simply choose the appropriate download file on the right and install VITESS on your computer. The VITESS installation includes some example instruments to demonstrate the main features of the program. You can also use the examples as an initial aid for your own instruments. For any questions and feedback of all kind you may contact the VITESS developers team, vitess@fz-juelich.de, and we will help you as quickly as possible. Subscribe to our facebook page to stay up-to-date concerning important announcements and new software releases!

Latest versions

The current VITESS version is 3.4. As new features, it allows reading and writing neutron data in MCLP and MCNPX format and contains the description of the ESS Butterfly-1 moderator. We invite you to download and install the new release and give us feedback on your experiences. Please also take a look at the version history

Vitess 3.3: Various minor changes compared to version 3.2.

Vitess 3.2: Upgrade of the monochromator module and new features of the detector and powder/single crystal sample modules.

Vitess 3.1: A numerical optimization framework and support for an efficient distribution of calculations on a Linux computer cluster included.

Vitess 3.0: Visualisation of instruments and neutron trajectories included.

Concept of VITESS

The simulation of a neutron instrument comprises several modules, which represent instrument components like guides or detectors, various helper modules, e.g. frames modifying the coordinate system between two instrument components, and modules for data visualisation and evaluation. All modules can be selected within the GUI. When you run a simulation, such modules are co-working sequentially embedded in a pipe structure:

  • Each module processes and then passes neutron data to the following one.

  • The first module must be either a neutron source module, or it must read information about the neutron trajectories from a file typically created in an earlier simulation of the preceding part of your instrument, which includes the source module.

  • The last module may be set up to write a file of neutron trajectories.  This makes sense if you wish to use these trajectories in further simulations  as input, e.g., for future studies of parameter distributions of these neutrons.

Workshops on VITESS
Applications of VITESS


enlarged view

A view of the VITESS GUI including two diagrams created in the simulation.


enlarged view

Visualisation of the ODIN instrument at IFE Institute Oslo, Norway. (X3D file)

Developer Team

To improve and adopt the VITESS software to a broader base we invite volunteers to join team of contributing developers. If you have written your own module that you would like to share with the public, you are welcome to provide us the code by sending this to the mailing list vitess@fz-juelich.de. We will put your code and help information indicating the author's name. We only require that components that are destined for an official release are thoroughly tested and that you feel responsible for your module for at least a certain time. This is to ensure the quality and usability of yearly official releases.

  • Permanent: Michael Fromme, Klaus Lieutenant
  • Contributing: Sergei Manoshin, Andreas Houben, Mirko Boin, Phil Bentley
  • Former developers: Geza Zsigmond, Dietmar Wechsler, Friedrich Streffer, Dickon Champion, Daniil Nekrassov, Carolin Zendler

For support or information please contact the team of developers at vitess@helmholtz-berlin.de

VITESS has been partly supported by the SCANS network (FP5) and was supported by the NMI3-MCNSI Network (FP6) within the Research Infrastructures Activities of the Research and Technology Development Programme of the European Commission. It is currently part of the german in-kind contribution to the ESS project(WP K7).


The VITESS package is described in the following publications:

[1] D. Wechsler, G. Zsigmond, F. Streffer, F. Mezei, VITESS: Virtual instrumentation tool for pulsed and continuous sources, Neutron News 11/4 (2000) 25-28.

[2] G. Zsigmond, K. Lieutenant, F. Mezei, Monte Carlo simulations of neutron scattering instruments by VITESS - Virtual Instrumentation Tool for ESS, Neutron News 13/4 (2002) 11-14.

[3] G. Zsigmond, K. Lieutenant, S. Manoshin, H. N. Bordallo, J. D. M. Champion, J. Peters, J.M. Carpenter, F. Mezei, A survey of simulations of complex neutronic systems by VITESS, Nucl. Instrum. Methods Phys. Res A 529 (2004) 218-222.

[4] K. Lieutenant, G. Zsigmond, S. Manoshin, M. Fromme, H. N. Bordallo, J. D. M. Champion, J. Peters, F. Mezei, Neutron instrument simulation and optimization using the software package VITESS, Proc. SPIE Int. Soc. Opt. Eng. 5536, ed. M. Sanchez del Rio (2004) 134 - 145.

[5] C. Zendler, K. Lieutenant, D. Nekrassov, M. Fromme, Vitess 3 – Virtual Instrumentation Tool for the European Spallation, J. Phys. Conf. Ser. 528 (2014) 012036.

Additionally there is a large number of publications based on VITESS simulations. A list of them is easiest obtained using Google Scholar.