Virtual Neutron Scattering Experiments at MLZ and other Facilities

Topic  3
Main supervisor K.Lieutenant (
MLZ institution FZJ
Local supervisor 1 R.Mezei
Institution Mirrotron
Local supervisor 2 C.Mammen
Institution JJ-X-Ray
Local supervisor 3
Local supervisor 4
Title Virtual Neutron Scattering Experiments at MLZ and other Facilities
Description With the reduced number of neutron sources it gets more and more important to use beam time at neutron facilities as efficiently as possible. As the instrument performance could be improved significantly over the last years, measuring times have become shorter and time loss by instrument setting and sample exchange gets more and more important. One idea to improve the efficiency is to enable virtual experiments at the instrument: each instrument gets a digital twin using one of the existing programs for instrument simulation (VITESS, McStas, ….). A user can then perform a virtual experiment (using a known sample similar to the real one) before doing the real experiment. This allows deciding if the measurement can be performed at this instrument, finding proper instrument settings, estimating the needed beamtime and getting familiar with the handling of the instrument. All this will help using the beamtime much more efficiently. Though this idea is not new, virtual experiments are not yet realized in most facilities. Implementing the virtual experiment concept requires new features in the simulation program, inclusion of the virtual experiment in the operating system and access via a web interface. A first candidate is MARIA at MLZ, but it should be extended to other MLZ instruments as well as instruments at other sources, e.g. at ESS or at HBS, which is currently designed at FZJ. Much preparative work, both on the VITESS package and on the operating system NICOS at MLZ, has already been done or will be finished in the near future. Also, a simulation of the instrument exist already. However, there is still much work to be done in order to get virtual experiments running: – writing the missing features needed to simulate a virtual experiment if applicable; – simulation of the instrument emulating the handling of the real instrument; – connecting it to the data evaluation;  including it in NICOS; – realizing it as a web application; – determining expected measurement statistics. The realization of this project will for the first time allow MLZ to operate full virtual experiments that can be used to prepare the real experiment or for teaching purposes, e.g. at a university or at the facility.