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McStas - A neutron ray-trace simulation package
|
| The plot shows the intensity of scattered neutrons (red is
highest intensity). The sample is at the center of the sphere with the
neutron beam coming from the left. Clearly seen is the shadowing effect
of the sample causing a lower intensity opposite the beam. Also seen is
the effect of the non-symmetric geometry of the sample, causing lower intensity
directly above and to the side of the sample. |  |
Simulated
scattering from a hollow-cylinder Recent news
Migrating from McStas 2.x to 3.x? - Use the wiki-based guides
September 23rd, 2023: McStas 3.4 Docker and Binder available
Dear all,
A Ubuntu 22.04 + McStas-3.4 + McStasScript image is now uploaded to dockerhub. To run from your local podman / Docker / etc. installation, execute a command along the lines of:
podman run -p 8888:8888 docker.io/mccode/mcstas-3.4
+ follow instructions from podman/Docker
You may also run the same container via binder, please connect via
this icon: 
To start McStas, please issue the command mcgui from a terminal.
September 21st, 2023: McStas 3.4 linux 'meta-packages' respun
Dear all,
A minor hickup was found with our Debian/Fedora metapackages that
both had a dependence on mcstas-mcpl-3.4 which is a
non-existent package.
Newly built, corrected meta-packages have been uploaded as replacement, so please re-attempt installation if you experienced issues earlier.
Also, please be aware that mcpl and NCrystal now come
in separate, non-McStas related packages - and are not included in
the "metapackage" on Fedora. To install them, simply execute
sudo dnf install mcpl ncrystal
Sorry for any inconvenience caused!
September 19th, 2023: McStas 3.4 released
Dear all, The new McStas release v. 3.4 "next-generation" is built and ready for download!
McStas 3.4 is the fifth official release in the 3.x series, with a modernised code-generator and support for GPU acceleration on NVIDIA cards.
3.4 is a 'major' update with notable changes, e.g. tighter integration/interoperability with McStasScript, new grammar and further CMake-standardisation which will eventually bring McStas to the conda-forge ecosystem. (And todaay, almost all dependencies for McStas are brought by mamba/conda on macOS and Windows.) Thanks to Thomas Kittelmann (ESS) for lots of help and footwork!
Another notable change is that MCPL and NCrystal are now
distributed in stand-alone .deb / .rpm packages that are
McStas-release-independent, for convenience still available through the
packages.mccode.org repository. Please install using e.g.
apt install mcpl ncrystal
(The MCPL and NCrystal codes have been submitted to the
Debian ecosystem by Synchrotron SOLEIL / Emmanuel Farhi / Roland Mas
and should make it to the next Debian Stable, the same procedure is
also under way for McStas.)
Thanks:
Thanks to all members of the joint McStas-McXtrace team and input from our users via emails and GitHub issues alike!
Download and installation instructions are available via our GitHub INSTALL-doc pages.
Selected highlights from the releass are listed below. The full
list changes is also available at https://mcstas.org/CHANGES_McStas.
Dear all,
The new McStas release v. 3.3 "next-generation" is built and ready for download!
McStas 3.3 is the fourth official release in the 3.x series, with a modernised code-generator and support for GPU acceleration on NVIDIA cards.
3.3 could have been considered a 'minor' update, but new built-in
support for NeXus on all platforms and new Thanks:
Download and installation instructions are available via our GitHub INSTALL-doc pages.
Selected highlights from the releass are listed below. The full
list changes is also available at https://mcstas.org/CHANGES_McStas.
If you didn't start already, please start your migration to 3.x:
Fixes of issues from last 3.x release: Release highlights Our Docker and binder containers will be updated within the
following weeks.
We hope you will enjoy this new release!!!
Previous news items: 2022, 2021,2020,2019, 2018, 2017, 2016,
2015, 2014, 2013,
2012, 2011, 2010, 2009,
2008, 2007, 2006,
2005, 2004, 2003, 2002, 2001, 2000, 1999,
1998.
We hope you will enjoy this new release!!!
(!!! Please note that there will be no future
2.x releases !!!)
mcrun --help
in your McStas terminal to learn
about details of switches and parameters or see the the changelog
for a full description.
mcstas-pygen Instrument.instr generates the .py
script Instrument_generated.py
Using 'jupytext' this file may easily be converted to a notebook:
jupytext --to ipynb Instrument_generated.py
generates notebook file Instrument_generated.ipynb
See https://github.com/PaNOSC-ViNYL/McStasScript
and https://mads-bertelsen.github.io for more information on McStasScript.
DEFINE INSTRUMENT template(lambda / "Aa" =
2.36)
see the changelog
for full description.
METADATA grammar from Greg S. Tucker (ESS), can
be used to attach verbatim code/information to one or more
component instances. See the changelog
for full description.
March 31st, 2023: McStas 3.3 released
SEARCH grammar warrant the .x increment.
Thanks to all members of the joint McStas-McXtrace team and input from our users via emails and GitHub issues alike!
- If you are still in trouble, please write us a GitHub issue or an email to mcstas-users@mcstas.org
A number of issues from 3.2 were addressed, see the relevant GitHub issues for details:
3.2 issue list
mcrun now automatically adds NeXus support to your binary if --format=NeXus is given on the
commandline (or if DEPENDENCY " @NEXUSFLAGS@ " is
included in your instrument or component file).
--IDF will run an IDF generator (i.e. mcdisplay-mantid) prior to performing
a NeXus-based simulation, i.e. for "one-click" support of output in Mantid-compatible NeXus
format with an embedded IDF. Please consult the naming-conventions for sourceMantid, sampleMantid
and nD_Mantid_xx found in https://github.com/McStasMcXtrace/McCode/wiki/McStas-and-Mantid#mcstas-mantid-workflow
to succesfully generate your IDF. Please also inspire from the example instruments in the Mantid
category, see mcgui -> File -> New from template -> Mantid .
mcrun now forwards the -I input to the code-generator, which allows you to add a chosen folder
with extra components etc. to your search path. Setting the -I flag implies recompilation (-c).
(Please also note the related SEARCH grammar below which allows working on the component search
path directly via the instrument or component grammar.)
mcgui run dialogue now allows to directly specify --format=NeXus and --format=NeXus --IDF when starting a simulation.
mcdisplay-mantid has been given a good overhaul and now works properly with all of the supported
mantid-event-detector geometries of Monitor_nD: rectangular, cylindrical/banana and OFF-file based.
Thanks to Torben R. Nielsen and Celine Durniak (ESS) for repeated testing.
mcplot (-pyqtgraph) and numpy related bug was quickly spotted
and ironed out with the help of by Rose Robledo FZJ.
FZP_simple model.comp of Fresnel Zone-Plate (phenomenologic/closed-form thin-plate approximation) added
along with test instrument Test_FZP_simple.instr, work by Anders Komar Ravn (NBI), and Erik B Knudsen
(previously DTU, now Copenhagen Atomics)
Test_Monochromators.instr has been updated to include NCrystal_sample as a monochromator, plus
includes multiple ways of parametrizing Single_crystal lattice
orientation. (Please note that NCrystal support is still not complete on Windows.)
ConicTracer interface-component codes Conics_EH.comp, Conics_PH.comp, Conics_PP.comp
have been updated to allow specifying non-equidistant radii of the nested optical shells. Please
use vector radii={a,b,c,d,e} or initialization via an instrument-based array and use a compatible
setting of nshells.
Elliptical_guide_gravity.comp will now complain if you are using arrays for specifying varied coating
without setting the nSegments input.
Pol_guide_vmirror.comp has been ported to 3.3.
Thanks to Damian Rodriguez and Hal Lee (ESS) for interactions on this component.
ESS_butterfly component may be modified using
compile-time re-definition. Defaults are
ESS_SOURCE_DURATION0=2.857e-3 s,
ESS_SOURCE_FREQUENCY 14 Hz,
ESS_SOURCE_POWER 5 MW. (Use e.g. mcrun --D1=ESS_SOURCE_DURATION=1.0e-3 to simulate a 1 ms pulse.)
pol-lib may also be redefined at compile-time,
defaults are: MCMAGNET_STACKSIZE=12,
mc_pol_angular_accuracy=(1.0*DEG2RAD) deg,
mc_pol_initial_timestep=1e-5 s.
SEARCH has been added to the grammar, allowing users to run append a directory
to the mcstas search path when looking for components. The syntax may be given in the
instrument- or component-header directly after a SHELL token and before the DEPENDENCY, DECLARE
tokens, available in two variants:
But you may also apply the same two SEARCH "/the/path/to/add/"
SEARCH SHELL "the_executable --and --some --options"
SEARCH forms in connection with a component instance in TRACE, e.g.:
TRACE
...
SEARCH SHELL "readout-config --show compdir"
COMPONENT readout = Readout(ring="RING", fen="FEN", tube="TUBE", a="left", b="right", ...)
AT (0, 0, 0) ABSOLUTE
...
(r-)interoff-lib.c family of codes have again received a couple of updates, thanks to McStas user
Richard Wagner (ILL).
NCrystal library version 3.5.1 from T. Kittelmann (ESS) and X.X. Cai (CSNS), distributed
with McStas on Unix platforms only. (Cross-compiles for Windows, but still needs work
for "production" availability.)
MCPL library from the same authors included at v. 1.6.1
