14.4  The SNS_source McStas Component

Modified: G. E. Granroth Nov 2014 Move to Mcstas V2 Modified: J.Y.Y. Lin April 2021 to Fix race condition Modified: P. WIllendrup 2021 Move to Move to Mcstas Version 3 and enable GPus

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

Identification

• Author: G. Granroth

• Origin: SNS Project Oak Ridge National Laboratory

• Date: July 2004

Description

Produces a time-of-flight spectrum from SNS moderator files moderator files can be obtained from the SNS website. IMPORTANT: The output units of this component are N/pulse IMPORTANT: The component needs a FULL PATH to the source input file Notes: (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 focus_xw and focus_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.

Links

• Component source code found in file SNS_source.comp.