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McStas: SNS_source Component

[ Identification | Description | Input parameters | Output parameters | Links ]

The SNS_source Component

A source that produces a time and energy distribution from the SNS moderator files


  • Author: G. Granroth
  • Origin: SNS Project Oak Ridge National Laboratory
  • Date: July 2004
  • Version: 1.01


Produces a time-of-flight spectrum from SNS moderator files
moderator files can be obtained from the SNS website .
The output units of this component are N/pulse
(1) the raw moderator files are per Sr.  The focusing parameters provide the solid
angle accepted by the guide to remove the Sr dependence from the output. Therefore 
the best practice is to set xw and yh to the width and height of the next beam 
component, respectively. The dist parameter should then be set as the distance 
from the moderator to the first component.
(2) This component works purely by interpolation. Therefore be sure that Emin and 
Emax are within the limits of the moderator file

Input parameters

Parameters in boldface are required; the others are optional.
Name Unit Description Default
S_filename - Filename of source data  
width m width of moderator  
height m height of moderator  
dist m Distance from source to the focusing rectangle  
xw m Width of focusing rectangle  
yh m Height of focusing rectangle  
Emin meV minimum energy of neutron to generate  
Emax meV maximum energy of neutron to generate  

Output parameters

Name Unit Description Default


[ Identification | Description | Input parameters | Output parameters | Links ]

Generated automatically by McDoc, Peter Willendrup <> / Wed Feb 1 10:20:35 2012

Last Modified: Wednesday, 12-Jan-2022 14:57:17 CET
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