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McStas: SNS_source_analytic Component

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

The SNS_source_analytic Component

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


  • Author: F. X. Gallmeier
  • Origin: SNS Oak Ridge National Laboratory
  • Date: October 18, 2010
  • Version:(Unknown)


Produces a time-of-flight spectrum from SNS moderator files
moderator files can be obtained from the author
IMPORTANT: The output units of this component are N/pulse
IMPORTANT: The component needs a FULL PATH to the source input file
(1) the raw moderator files are per Sr.  The parameters focus_xw focus_yh and dist 
provide the solid angle with which the beam line is served. 
The best practice is to set focus_xw and focus_yh to the width and height of the 
closest beam component, and dist as the distance from the moderator 
location to this component.
(2) Be sure that Emin and Emax are within the limits of 1e-5 to 100 eV
(3) the proton pulse length T determines short- and long-pulse mode 

Beamport definitions:
BL11: a1Gw2-11-f5_fit_fit.dat
BL14: a1Gw2-14-f5_fit_fit.dat
BL17: a1Gw2-17-f5_fit_fit.dat
BL02: a1Gw2-2-f5_fit_fit.dat
BL05: a1Gw2-5-f5_fit_fit.dat
BL08: a1Gw2-8-f5_fit_fit.dat

WARNING: This is a contributed Component.

Input parameters

Parameters in boldface are required; the others are optional.
Name Unit Description Default
filename - Filename of source data  
xwidth m width of moderator (default 0.1 m) 0.10
yheight m height of moderator (default 0.12 m) 0.12
dist m Distance from source to the focusing rectangle (no default)  
focus_xw m Width of focusing rectangle (no default)  
focus_yh m Height of focusing rectangle (no default)  
Emin meV minimum energy of neutrons (default 0.01 meV) 0.01
Emax meV maximum energy of neutrons (default 1e5 meV) 1.0e5
tinmin us minimum time of neutrons (default 0 us) 0.0
tinmax us maximum time of neutrons (default 2000 us) 2000.0
sample_E - sample energy from: (default 0) 0="probability distribution", 1="energy range", 2="lambda range", 3="log(energy) range" 0
sample_t - sample t from: (default 0) 0="probability distribution", 1="time range" 0
proton_T us proton pulse length (0 us) 0.0
p_power MW proton power (default 2 MW) 2.0
n_pulses default 1 number of pulses 1.0

Output parameters

Name Unit Description Default


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

Generated automatically by McDoc, Peter Willendrup <> / Wed Apr 19 10:57:33 2017

Last Modified: Wednesday, 19-Apr-2017 12:57:33 CEST
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