December 12th, 2018: McStas 2.5 release!

Dear all,

Our 20-year anniversary release McStas 2.5 has been built and is ready for download! Download and installation instructions are available via our GitHub download pages

Selected highligts from the release are listed below. The full list of changes is also available at http://mcstas.org/CHANGES_McStas.

Greetings and merry X-mas from the McStas team - hope you will enjoy this new release! :-)

Peter Willendrup

Changes in McStas v.2.5, December 12th, 2018

McStas 2.5 is the seventh release in the 2.x series and fixes various issues with McStas 2.4.1, plus many new developments. McStas 2.5 is also the 20th anniversary release of McStas - 1.0 was released in October 1998!

Thanks:
Thanks to all contributors of components, instruments etc.! This is what Open Source and McStas is all about!

Installation:
Our install docs are now available on the McCode GitHub page at https://github.com/McStasMcXtrace/McCode/tree/master/INSTALL-McStas

Fixes of issues from last release:
A number of issues from 2.4.1 were corrected, see the relevant GitHub issues for details: https://github.com/McStasMcXtrace/McCode/issues?&q=is%3Aissue+is%3Aclosed+label%3A%22McStas+2.4.1%22+

Plus lots of work in general:
https://github.com/McStasMcXtrace/McCode/issues?&q=is%3Aissue+is%3Aclosed++project%3AMcStasMcXtrace%2FMcCode%2F1+

Tools:

As for the earlier few releases the default set of tools are Python-based and developed by Jakob Garde, DTU.
- The Perl ones are still around as a backup solution, handy for those that prefer "the oldschool way"
- See https://github.com/McStasMcXtrace/McCode/wiki/User-documentation-for-the-2017--Python-tool-set for usage
- On Unix platforms, the Perl tools are accessible by adding .pl to the wanted tool (mcgui.pl etc.)
- On Windows, the Perl tools are accessible by adding -pl to the wanted tool (mcgui-pl etc.)
BUT: Please use the Python tools and provide feedback rather than sticking with the Perl! :-)
Feature developments:
- mcgui: For a quick visualisation of your instrument, simply useSimulation -> Display-2D and Display-3D (will use the default instrument parameters)
- mcgui: The run-dialogue now gives quick access to all mcdisplay and mcplot utilities as comboboxes
- mcdoc: We now provide a mcdoc utility based on Python

Platforms:

Our Windows release is finally 64bit. Also further prepackages GSL for use e.g. with Multilayer_sample.comp from R. Dalgliesh (ISIS)
If you want to use NeXus and / or MPI on Windows, please ensure to install Strawberry perl!

Libraries:

NCrystal library from T. Kittelmann (ESS) and X.X. Cai (DTU Nutech/ESS) is distributed with McStas on Unix platforms. To use it, carry out the below steps:
- !!! To enable ncrystal with McStas on Linux systems please:
  - install the mcstas-ncrystal-2.5 package
  - (re-)install the mcstas-tools-python-mcrun-2.5 package
- mcstas:~/NCryst$ mcstas-2.5-environment
- mcstas:~/NCryst$ source $MCSTAS/ncrystal/setup.sh
- mcstas:~/NCryst$ ncrystal_preparemcstasdir
- mcstas:~/NCryst$ cp $MCSTAS/examples/NCrystal_example_mcstas.instr .
- mcstas:~/NCryst$ mcrun -c NCrystal_example_mcstas.instr
MCPL library from the same authors now included at v. 1.2.3

Components:

Single_crystal_inelastic.comp is a development from Duc Le (ISIS) and presents our attempt at a general, inelastic single crystal component. iFit can be used to generate its input, see http://ifit.mccode.org/McStas.html#mozTocId36233
E_4PI.comp is a monitor also from Duc Le, used to illustrate the output of his inelastic component in the instrument Test_Single_crystal_inelastic.instr
Magnon_bcc.comp is new inelastic component from K. Lefmann (KU), used in Test_Magnon_bcc_TAS.instr and Test_Magnon_bcc_2D.instr
Isotropic_Sqw.comp from E. Farhi has recieved a number of important edits, including correctiono of a bug found by S. Bellissmia (CNR) relating to detailed balance
PowderN received a bugfix from M. Bertelsen (KU) and a set of focusing patches from J. Saroun (NPI)
NPI_tof_dhkl_detector.comp and NPI_tof_theta_monitor.comp are new monitor components from J. Saroun (NPI), used in his model of the ESS BEER instrument, see below
Guide_multichannel.comp is a new component from J. Saroun (NPI), based on Guide_channeled.comp. It allows to simulate bi-spectral extraction optics.
Sqq_w_monitor.comp is a development from P. Willendrup (DTU) and is a "scattering plane" monitor that outputs a set of energy-slices over a (qh,qk) reciprocal space plane, used in Test_Magnon_bcc_2D.instr
Pol_guide_mirror.comp is a development from E. Knudsen (DTU) which among other use cases allows to simulate a so-called "frame overlap mirror" as envisioned for multiple ESS instruments
Pol_Bfield.comp from E. Knudsen (DTU) has been updated to allow more flexible geometry and "rotatable" tabulated field descriptions. It replaces Pol_simpleBfield which is now in obsolete.
Absorber.comp received a bugfix thanks to Artur Glavic (PSI)
FermiChopper.comp had a long-standing issue when using supermirror coatings in the slit-package which is now fixed, thanks to Ryoichi Kajimoto (J-PARC)
All monitors can now suppress file-output when their standard input parameter "nowritefile" is true. The idea is to be able to suppress (some) output at runtime, e.g. in simulations with lots of monitors.

Instruments:

ESS_Testbeamline_HZB_V20.instr from Alaa Al-Falahat and Robin Woracek (ESS/HZB) is a model of the ESS test- beamline in Berlin
ESS_BEER_MCPL.instr from J. Saroun (NPI) is a model of the ESS BEER secondary spectrometer. It uses MCPL input calculated via SIMRES
BTsimple.instr from P. Willendrup (DTU) shows a simple method to calculate brillance transfer through a guide system
ILL_H142_D11.instr and ILL_H142_D33.instr from E. Farhi (ILL) are models of the optics in the two well-known ILL SANS instruments
ILL_H5_new.instr from E. Farhi (ILL) is a model of the ILL IN5 spectrometer after the guide upgrade in 2011
ILL_IN5_Spots.instr modified byP. Willendrup (DTU) is a model of the ILL IN5 spectrometer with multiple resolution-calculation options
ISIS_IMAT.instr from G. Burca (ISIS) is a model of the ISIS IMAT engineering-beamline
ISIS_SANS2d_Mantid.instr from T. R. Nielsen (ESS) is a model of the ISIS SANS2d instrument with sample and a Mantid output possibility
ISIS_TOSCA_preupgrade.instr and ISIS_TOSCA_preupgrade_Mantid.instr from P. Willendrup and S. Mukhopadhyay, based on an earlier model by M.Zanetti are models of the TOSCA spectrometer at ISIS
NCrystal_example_mcstas.instr by X.X. Cai (DTU/ESS) is used to illustrate the use of the NCrystal library in McStas
Test_DiskChoppers.instr by P. Willendrup (DTU) compares the use of 2 DiskChoppers with one MultiDiskChopper
Test_Magnon_bcc_TAS.instr from K. Lefmann (KU) and Test_Magnon_bcc_2D.instr P. Willendrup (DTU) illustrate the use of the new Magnon_bcc.comp
Test_Single_crystal_inelastic.instr from Duc Le (ISIS) is a test instrument for Single_crystal_inelastic.comp
Test_Pol_Guide_mirror.instr from E. Knudsen (DTU) is a test instrument for Pol_guide_mirror.comp
Test_focus.instr from T. Weber (ILL) compares focusing by Single_crystal and Monochromator_curved

We hope you will enjoy this 20th anniversary release!!!

November 6th, 2018: McStas user survey 2018

Dear all,
To assess the current use of McStas, we have put together the below survey for users of our neutron Monte Carlo ray-tracing package.
Using the survey results, we hope to gain insight and statistics on the McStas user community, where it is currently based, which operating systems and computing infrastructures are used, and to what satisfaction the package, support infrastructure and documentation is used. The survey should also give us a clear picture where to focus our future efforts.
We hope you will help us by investing a few minutes in the survey:
https://www.surveymonkey.com/r/L38RXZG
On behalf of the McStas team,
Peter Willendrup

September 29th, 2018: Release 2.4.1 works OK on macOS 10.14 Mojave
Dear all,
I can confirm that the latest McStas works fine on the newest macOS release, even though the distributed "Check-PL-dependencies" script will report both 10.13 and 10.14 as an unsupported macOS releases.
If you need to install our Perl-based tool chain on 10.13 High Sierra or 10.14 Mojave, the easiest way is to download an updated version of the above script, get it from our GitHub (I will also put a copy alongside the existing .tgz for download)
If, after an upgrade to Mojave you get compilation issues with the error message
mccode-r.h:39:18: fatal error: math.h: No such file or directory
then please run the following commands in a terminal:

xcode-select --install
- to initiate installation of updated Xcode commandline tools
sudo open /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg
- to install the development headerfiles in the usual /usr/include location

May 18th, 2018: MDANSE 2018

Does the combination of DFT or classical MD with McStas for modeling experimental data sound interesting?
If so, please consider participating in the MDANSE 2018 event in Tenerife this fall. Registration closes on May 31st 2018.

(You can also read more in this a post to mcstas-users)

April 30th, 2018: Release 2.4.1 works OK on Ubuntu 18.04 + a workaround
Dear all,
I have tested McStas 2.4.1 with the recent Ubuntu 18.04 LTS "bionic beaver", and the usual installation recipe works.
The only found issue so far relates to the behaviour of the Perl+PGPLOT mcplot.pl plotter which out of the box fails with the error message: "%giza - ERROR - giza_open_device: Unknown device, device not opened" (see below graphics also).

(In fact the problem was known already for Debian testing, see our related GitHub issue)
The following solutions/workarounds exist:

Recommended:
Use the Python-based pyqtgraph plotter instead, i.e. mcplot (or mcplot-pyqtgraph). This would give you graphics like this:

Configure pgplot/giza for "XWIN" driver:
Either edit your /usr/share/mcstas/2.4.1/tools/Perl/perl/mccode_config.perl replacing XSERV with XWIN or set the related environment variable in the shell, i.e.
export PGPLOT_DEV=/XWIN
The solution will give you this appearance:

Force-configure to use the legacy PGPLOT:
Use these commands in a shell and get your "normal" PGPLOT window back
cd /usr/lib/x86_64-linux-gnu sudo ln -sf ../libpgplot.so libpgplot.so.0
sudo ln -sf ../libcpgplot.so libcpgplot.so.0
The solution will give you this appearance (as usual):

March 2018: McStas-McXtrace team participates in GPU Hackathon

As some of you may have already seen via our facebook page or on twitter, a joint McStas-McXtrace team visited the 2018 GPU Hackathon in Dresden in March.
We can not a such claim that the software fully runs on NVIDIA GPU's, but we certainly gained knowledge and will investigate further. :-)
The team pariticpating in Dresden were

DTU: Peter Willendrup, Jakob Garde, DTU Physics and Giovanni Fevola, DTU Energy
ILL: Emmannuel Farhi, ILL Spectroscopy Group / Computing for Science
UCPH: Mads Bertelsen, Niels Bohr Institute

Here is a few photos from the event - and also a PDF from the final presentation, put together by Mads Bertelsen, University of Copenhagen

Previous news items: 2017, 2016, 2015, 2014, 2013, 2012, 2011, 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003,2002, 2001, 2000, 1999, 1998.