[ 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

Identification

• Author: G. Granroth
• Origin: SNS Project Oak Ridge National Laboratory
• Date: July 2004
• Version: 1.6
• Modification history:
  • E. Farhi, uniformize parameter names (Jul 2008)

Description

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
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 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 filename

Example: SNS_source(S_filename="source_sct091_tu_02_1.dat",
                       width=0.1, height=0.12,
                       dist=1, xw=0.10, yh=0.24, Emin=1.0,Emax=10.0)

WARNING: This is a contributed Component.

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
S_filename	str	File of source data	0
width	m	Width of moderator	0.1
height	m	Height of moderator	0.12
dist	m	Distance from source to the focusing rectangle	0
xw	m	Width of focusing rectangle	.1
yh	m	Height of focusing rectangle	.24
Emin	meV	Minimum energy of neutron to generate	1
Emax	meV	Maximum energy of neutron to generate	10
target_index	1	relative index of component to focus at, e.g. next is +1 this is used to compute 'dist' automatically.	+1

Output parameters

Name	Unit	Description	Default
hdiv
vdiv
p_in
inxvec
inyvec
Pvec
xylength
tcol
Ecol
txval
tyval
tPvec
Ptmat
EPmax
EPmin
INorm
INorm2
ntvals
idxstart
idxstop
tidxstart
tidxstop
nEvals
xonly
Pfunc
txonly
tPfunc

Links

• Source code for SNS_source.comp.
• Source files SNS_test example instrument

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

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Last Modified: Friday, 11-May-2012 10:41:09 CEST