MCNSI is an abbreviation of ”Monte Carlo Simulations of Neutron Scattering Instruments”.
This JRA has developed and tested software which can be used to describe neutron instrumentation.

The back-bone of the MCNSI JRA is the three software packages for neutron ray-tracing Monte-Carlo simulation: McStas, VITESS, and RESTRAX.
This JRA has developed these packages with three main goals:
a) New capabilities for the packages, including updated documentation;
b) Testing of the packages, by intercomparison and by comparing with experiments;
c) Development of the concept of virtual experiments.

The main results of MCNSI are essentially strongly improved versions of the three packages, including the know-how of simulating neutron instrumentation. The package testing efforts have meant a tremendeous increase of reliability and confidence of the packages. Finally, it has been demonstrated that virtual experiments have a great potential for as varied applications as instrument design, experiment planning, on-the-fly diagnosis, data analysis, and teaching/training of students and new users. The simulation packages are in use worldwide at all facilities, and any neutron instruments under construction has been designed using (at least) one of these packages.

Partners
The JRA has consisted of 3 paid partners: HMI, NPI, and Risø, plus 5 partners with almost negligible budgets: ISIS, ILL, PSI, Jülich, and INFM. The paid partners have been responsible for the daily maintenance of the three simulations packages, but significant contributions to maintenance, testing, and further development have come from all partners. In particular, ILL has been co-responsible for McStas developments, Jülich has been co-responsible for VITESS developments, and PSI has taken responsibility for code intercomparisons.

Meetings
MCNSI has had two meetings in 2004, 2005, and 2006, while only one meeting in 2007 (the autumn meeting was postponed till January 2008). In addition, MCNSI has arranged a number of training schools and workshops (ISIS 2004, ILL 2005, Rencurel 2006, PSI 2006, Lund 2007, HMI 2008).



Official MCNSI Website: MCNSI Web
Coordinator: Kim Lefmann