[neutron-mc] NOP

[Alianelli, L (Lucia)]

Hi Tom,
 
it seems that the energy scan type is not optimised in NOP. So I would suggest you look at angular scans, i.e. rocking curves.
 
I attach the rocking curve for lambda = 0.04 nm. The Bragg angle is about 7 degrees, not 21.5. At 21.5 deg you would find zero intensity.
 
Of course you are going to get an error when trying lambda = 0.7 nm or 7 Angstrom. The reason is that the Si 311 d-spacing is 1.64 Angstrom, so you cannot find any Si 311 Bragg reflection for such cold neutrons!!!!
 
Also are you interested in perfect crystal reflectivity? 
Or reflectivity from a mosaic or bent crystal? 
 
Regards,
 
Lucia
 
 
If you want to look at theory, measurements and simulations of neutron reflectivity from crystals, you can look at the bibliography in my thesis:
http://www.esrf.eu/computing/scientific/people/srio/publications/alianelli_thesis.pdf 
 

________________________________

From: neutron-mc-bounces at risoe.dk [mailto:neutron-mc-bounces at risoe.dk] On Behalf Of wokaoyan1981
Sent: 25 April 2008 06:27
To: McStas
Subject: [neutron-mc] NOP


Hi all，

I installed XOP2.1beta3 and its extension NOP to obtain reflectivity files required for  perfect Si(311) crystal monochromator in RS visualization. The mission is to take an energy scan within 0.04 and 0.7nm at grazing angle 21.5 degrees.It is a pity that I met some problems.

Here is what I did:
1. Implement the module NCRYSTAL;
2. Set parameters as the Screenshot，please see enclosures;
   (My Email doesn't support image upload.)
3. "Accept" and double click "28Si";
4. "Show" diffraction curve.

In Xplot Window I found nothing. The X coordinate doesn't show desired range.

Please help! I am looking forward your reply.

Yours sincerely,
Tom 
 
 
 


________________________________

送！送！送！瑞星2008半年免费！ <http://popme.163.com/link/004290_0422_5595.html> 
<DIV><FONT size="1" color="gray">This e-mail and any attachments may contain confidential, copyright and or privileged material, and are for the use of the intended addressee only. If you are not the intended addressee or an authorised recipient of the addressee please notify us of receipt by returning the e-mail and do not use, copy, retain, distribute or disclose the information in or attached to the e-mail.
Any opinions expressed within this e-mail are those of the individual and not necessarily of Diamond Light Source Ltd. 
Diamond Light Source Ltd. cannot guarantee that this e-mail or any attachments are free from viruses and we cannot accept liability for any damage which you may sustain as a result of software viruses which may be transmitted in or with the message.
Diamond Light Source Limited (company no. 4375679). Registered in England and Wales with its registered office at Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom
</FONT></DIV> 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman2.mcstas.org/pipermail/mcstas-users/attachments/20080425/224d44ef/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: si311_neutron511mev.doc
Type: application/msword
Size: 33792 bytes
Desc: si311_neutron511mev.doc
URL: <http://mailman2.mcstas.org/pipermail/mcstas-users/attachments/20080425/224d44ef/attachment.doc>