McStas - A neutron ray-trace simulation package
McStas is a general tool for simulating neutron scattering instruments
and experiments. It is actively supported by DTU Physics
, NBI KU
scattering from a hollow-cylinder vanadium
|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.|
February 19th, 2015: Bugfixed-release of the ESS_moderator.comp
Jan Saroun from NPI in Czech Republic (and author of
RESTRAX/SIMRES) has spotted an unfortunate error in the
ESS_moderator.comp component, relating to the 2014 "pancake" case.
The bug is a missing distance-factor in a solid-angle computation
and will lead to a too high brilliance emitted from the source.
Unfortunately was never spotted in our tests since these happen with an
instrument where this distance is set to 1 m... (and 1 x 1 = 1... )
The updated source packge for use with McStas 1.12c and 2.x is
available for download at http://mcstas.org/download/share/ESS_moderator_February_2015.tgz. A
set of "release notes" is available at http://mcstas.org/download/share/ESS_moderator_February_2015.tgz.html.
Sorry for any inconvenience this may cause.
February 10th, 2015: Supplemental documentation for ESS moderators in McStas
A number of McStas users have expressed that the documentation for the
ESS_moderator component distributed with McStas is not completely
clear. To remedy this, Ken Andersen and I have (with the help of data
from Troels Schönfeldt) produced a supplemental PDF document that will hopefully help.
Please note that at this point, only TDR-like and pancake moderators
are described in McStas. An updated set of moderator descriptions will
be released with McStas 2.2 during the spring of 2015.
Previous news items: 2014, 2013, 2012, 2011, 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003,2002, 2001, 2000, 1999,
Last Modified: Thursday, 19-Feb-2015 11:02:02 CET