User and Programmers Guide to the Neutron Ray-Tracing Package McStas, version 3.8.6

3.1  Installation and updates

For installation notes, see the web site [Mcs]. In case of problems, write the support mailing list, or contact the authors.

Installation via conda-forge (recommended)

The recommended installation method for all supported platforms—Linux, macOS, and Windows—is via the conda-forge channel. Once a conda-compatible environment manager such as Miniforge or Mambaforge is available, McStas can be installed into a fresh conda environment:

  conda create -n mcstas -c conda-forge mcstas
  conda activate mcstas
  mcgui

On Windows a dedicated mcstas-conda batch script is provided by the installer. After it completes, use the mcstas-shell desktop shortcut and issue mcgui to start the graphical interface. Arm64 Windows is also supported via this route.

For full platform-specific installation instructions, including Linux package management and macOS options, see:

https://github.com/mccode-dev/McCode/tree/main/INSTALL-McStas

3.1.1  Important note for Windows users

It is a known problem that some of the McStas tools do not support filenames / directories with spaces. We recommend avoiding spaces in the paths used for McStas work directories and instrument files. As of McStas 3.x, all tools (mcgui, mcrun, mcplot, mcdisplay, …) are pure Python and are bundled with the conda-forge package, so no separate Perl installation is required on any platform, including Windows.

3.1.2  New releases of McStas

Releases of new versions of a software package can today be carried out more or less continuously. However, users do not update their software on a daily basis, and as a compromise we have adopted the following policy of McStas.