[mcstas-users] Polycrystal sample model

[Erik Bergbäck Knudsen]

Dear Jon,

This is indeed something that is being worked on as we speak. Currently
a model exists in a workable but less user-friendly form, based on
extensive use of EXTEND-blocks to coaxing Single_crystal into behaving
as a polycrystal.

The basic idea is to model the polycrystal as set of voxels where each
voxel itself my be considered a singe crystal with individual
parameters. Texture could then be targeted by choosing the orientations
of the voxels from a certain distribution.

As mentioned, the present solution is not very user-friendly. The
working idea, though, is to promote this solution to an actual component
based on Single_crystal which should be easier to use.
Note that this will not be ready for the upcoming release 2.1 of McStas,
it might be for 2.2.

I'd be happy to help you get to grips with the model as it is, pending
the more polished solution.

cheers
Erik



On 04/29/2014 08:57 AM, Jon.James wrote:
>  
> Dear all,
>  
> Can anyone tell me if there is a general polycrystalsample model
> available for McStas? Or if anyone is developing, or planning to develop
> such a thing? I am thinking of something that could be used to model
> diffraction from large grains in the presence of texture; a
> situation such as might occur in a weld.
>  
> Thanks
>  
> Jon
>  
>  
> ------------------------------------------------------------- 
> Dr Jon James
> Research Fellow in Materials Engineering
> Materials Engineering
> The Open University
> Walton Hall, Milton Keynes, MK7 6AA
> 
> Jon.James at open.ac.uk <mailto:Jon.James at open.ac.uk>
> +44 (0) 1908 654198
> -- The Open University is incorporated by Royal Charter (RC 000391), an
> exempt charity in England & Wales and a charity registered in Scotland
> (SC 038302).
> 
> 
> _______________________________________________
> mcstas-users mailing list
> mcstas-users at mcstas.org
> http://mailman.mcstas.org/cgi-bin/mailman/listinfo/mcstas-users
> 

-- 
Erik Bergbäck Knudsen, Research Engineer         | DTU | morituri
NEXMAP, DTU Fysik, DK-2800 Kgs. Lyngby, Denmark  |<>-<>|    te
phone: (+45) 2132 3151, mobile: (+45) 3123 6184  |<>-<>| salutant