$$\renewcommand\AA{\unicode{x212B}}$$

# McStas - A neutron ray-trace simulation package¶

## Introduction to McStas¶

The McStas neutron ray-tracing simulation package is a versatile tool for producing accurate simulations of neutron scattering instruments at reactors and pulsed spallation sources. McStas is extensively used for design and optimization of instruments, virtual experiments, and user training. McStas is an abbreviation for Monte Carlo Simulation of triple axis spectrometers, but allows for describing and simulating any type of neutron scattering instrument.