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Abteilung Dynamik und Transport in Quantenmaterialien


the following list has not been updated for about 10 years


Instrumentation for the European Spallation Source

VITESS was originally  developed for the ESS Project. It was used to simulate large parts of the "instrument suite" for the evaluation of these intruments of the long pulse spallation source (LPSS) partly in comparison to instrument at other sources. This aims at the optimisation of moderator-instrument performances.


High Resolution Crystal Analyzer Spectrometers and Backscattering

Monte Carlo simulations of crystal monochromators/analysers carried out by VITESS offer a correct basis for the computation of the resolution function of crystal analyser backscattering spectrometers. For the design of new instruments the comparison of moderator performances is a crucial issue. This is currently one of the main applications of VITESS. MC simulations, which were first applied to support experiments on IRIS at ISIS, were also implemented in the HERMES project at LANSCE (Los Alamos).


Small Angle Neutron Scattering

Planned and existing SANS instruments are compared on three types of sources (CWS, SPSS, LPSS) to increase the intensity and efficiency. The SANS instrument V4 housed on the reactor source at HMI has been simulated and the results were in perfect agreement with the experimental data.


Neutron Spin Echo

A comprehensive Monte Carlo simulation study of NSE, of neutron instruments which use polarized neutrons, and the development of a general and flexible software are a next objective in the VITESS project at the HMI Berlin. MC computations reveal information on properties which are not easily accessible for experimental observation e.g. on the exact wavelength dependence of flipping efficiency, on details of correlations in the whole instrument and on the effect of stray fields. Simulations are in progress for TOF-NSE and SPAN (HMI).


Chopper Spectrometers

Cold neutron multichopper spectrometers for inelastic neutron scattering experiments offer a high flexibility in the wavelength selection and chopper speed which allows for a considerable optimisation of the energy range, the energy resolution, the momentum-transfer range and count-rate. An adaptation and optimisation for LPSS and SPSS sources is studied by MC simulations.


Powder Diffraction

A TOF powder diffractometer has recently been built at KFKI in Budapest. The first results of test measurements are in excellent agreement with the calculated resolution behaviour for this type of instrument.
Monte Carlo simulations have been performed for a time-of-flight monochromator powder diffractometer housed on a thermal moderator at a Long-Pulse Spallation Source and for a conventional monochromator instrument on a thermal moderator of a reactor source.



The intensity and resolution conditions of V6 (Reflectometer) at HMI will be investigated to improve geometry, the monochromator and the tuning relative to the sample. An adaptation and optimization for LPSS and SPSS sources is studied by MC simulations.