[ Identification | Description | Input parameters | Links ]

# The `SNS_source_analytic` Component

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

## Identification

- Site:
- Author: F. X. Gallmeier
- Origin: SNS Oak Ridge National Laboratory
- Date: October 18, 2010

## Description

    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
    Notes:
    (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

## 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 |
sample_t |  | sample t from: (default 0) | 0 |
proton_T | us | proton pulse length (0 us) | 0.0 |
p_power | MW | proton power (default 2 MW) | 2.0 |
n_pulses |  | number of pulses (default 1) | 1.0 |

AT ( | , | , |  | ) RELATIVE |  |
ROTATED ( | , | , |  | ) RELATIVE |

## Links

- Source code for `SNS_source_analytic.comp`.

[ Identification | Description | Input parameters | Links ]