Advanced computer simulations methods for neutron scattering instruments 2025

Session

Morning Session 2

11 Jul 2025, 10:20

R035 (DTU building 306)

Description

Updates from MCPL, NCrystal and Union, Virtual Experiments I

28. Update on the MCPL and NCrystal projects

Thomas Kittelmann (European Spallation Source ERIC)

11/07/2025, 10:20

This contribution aims to give users an update on the MCPL and NCrystal projects. These two open source projects, both maintained by the Modelling group at the ESS DMSC, aim to facilitate integration and collaboration between users of various Monte Carlo transportation codes. MCPL enables the interchange of particle states between codes, while NCrystal provides an ambitious backend for shared...

34. Introducing Effects of Surface Physics in McStas Union

11/07/2025, 10:40

The McStas Union components provide a framework to simulate complex systems, both in terms of scattering physics and geometry. Materials are defined using a combination of available scattering processes and an absorption cross-section. Geometry is described using a combination of basic shapes, including spheres, cones and boxes. These can be combined to form complex nested geometries. Multiple...

23. Virtual Experiments on the BIFROST Spectrometer at ESS

11/07/2025, 11:00

The applicability of inelastic neutron scattering is limited by inherently weak signals.
Mapping significant portions of (Q, ω)-space can take days, making parametric studies as a
function of temperature, pressure, and magnetic field essentially impossible. The triple-axis
community has addressed this limitation by improving the efficiency of triple-axis
spectrometers through the...

16. Digital Twins at MLZ: combining Vitess and McStas with NICOS

11/07/2025, 11:20

Over the last decades, the neutron user community has steadily grown more diverse. While initially experts in instrument and scattering techniques performed the experiments, now users come from various scientific backgrounds and use a a combination of many different methods in order to answer scientific questions. It is therefore more important than ever to provide them with excellent tools...

37. Contingency timeslot

11/07/2025, 11:40

12. The PUMA Virtual Instrument: Working Towards a User-Friendly Neutron Scattering Simulation

To increase neutron flux on small samples, we are developing a nested mirror optic (NMO) array for the PUMA thermal triple-axis spectrometer at the MLZ. This device is intended to reduce the beam size to 5 mm x 5 mm while preserving 50% of the incoming neutrons, re-sulting in an 8-fold increase in the flux available for small samples. However, the complex neutron flight paths generated from...