[mcstas-users] Rotating polarising mirror components

Robert Dalgliesh - UKRI STFC robert.dalgliesh at stfc.ac.uk
Fri May 29 17:50:20 CEST 2020

Peter, Erik,
I apologise, I've just noticed the note in the component description regarding the hard coding of the polarisation direction.
I will modify my simulations accordingly.

Sorry everyone


From: mcstas-users <mcstas-users-bounces at mcstas.org> On Behalf Of Robert Dalgliesh - UKRI STFC
Sent: 29 May 2020 15:25
To: McStas <mcstas-users at mcstas.org>
Subject: [mcstas-users] Rotating polarising mirror components

Hi Peter, Erik,
I've been looking in more detail at what happens when I rotate a polarising mirror or v-mirror in mcstas as a result of getting repeated assert errors from the polarisation being greater than 1.
I am having trouble working out if the polarisation vector is rotated correctly if e.g. Pol_mirror is rotated by 90deg to be in a horizontal rather than vertical geometry. The code performs a calculation of probabilities based on the sy component (GetMonoPolRefProb(FN, FM, sy, &refWeight)) but if I have a polarisation in the x-z plane prior to the component I have been unable to determine what is happening.
In order to makes things correct the incoming spin vector would need to be rotated by 90 degrees on entering the pol_mirror component. Is this done in some hidden way or do I need to rewrite the components to deal with this?



Dr. Robert Dalgliesh
ISIS Neutron and Muon Source
STFC Rutherford Appleton Laboratory
R3 1.29
Harwell Oxford
OX11 0QX
Office Tel: +44 (0) 1235 445687
Internal Mobile Extension: 1176

This email and any attachments are intended solely for the use of the named recipients. If you are not the intended recipient you must not use, disclose, copy or distribute this email or any of its attachments and should notify the sender immediately and delete this email from your system. UK Research and Innovation (UKRI) has taken every reasonable precaution to minimise risk of this email or any attachments containing viruses or malware but the recipient should carry out its own virus and malware checks before opening the attachments. UKRI does not accept any liability for any losses or damages which the recipient may sustain due to presence of any viruses. Opinions, conclusions or other information in this message and attachments that are not related directly to UKRI business are solely those of the author and do not represent the views of UKRI.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman2.mcstas.org/pipermail/mcstas-users/attachments/20200529/1dc6d90d/attachment.html>

More information about the mcstas-users mailing list