[neutron-mc] How to set parameters "dist" and "xw/yh"?

Linda Udby linda.udby at risoe.dk
Thu Jan 10 14:26:37 CET 2008

Dear Tom Chen,

Usually you would want only to be concerned with the neutrons from the 
source that actually goes in the guide.
Hence you would focus on the guide entrance.

The 'xw' and 'yh' sets the size of the focusing rectangle (here it 
would be guide width/height), 'dist' is the down-stream distance from the 
source to the focusing rectangle (here distance from source to guide entrance).

Hope this helps, otherwise you can always check the components manual at 

Linda Udby,
AFM, Risø

On Thu, 10 Jan 2008, wokaoyan1981 wrote:

> Dear colleagues,
> Why is it necessary to set parameters "dist"  ,"xw" and "yh" of the component Source_Maxwell_3?
> How to set them with regard to a source followed by a straight neutron guide?
> Please shed light on them thoroughly.Thank you!
> Tom Chen

M.Sc. Linda Udby
Materials Science Department
Risø National Laboratory, DTU
tel: +45 46 77 58 65

More information about the mcstas-users mailing list