[ Identification | Description | Input parameters | Links ]

The Source_simple Component

A circular neutron source with flat energy spectrum and arbitrary flux

Identification

• Site:
• Author: Kim Lefmann
• Origin: Risoe
• Date: October 30, 1997

Description

The routine is a circular neutron source, which aims at a square target
centered at the beam (in order to improve MC-acceptance rate).  The angular
divergence is then given by the dimensions of the target.
The neutron energy is uniformly distributed between lambda0-dlambda and
lambda0+dlambda or between E0-dE and E0+dE.
The flux unit is specified in n/cm2/s/st/energy unit (meV or Angs).

This component replaces Source_flat, Source_flat_lambda,
Source_flux and Source_flux_lambda.

Example: Source_simple(radius=0.1, dist=2, focus_xw=.1, focus_yh=.1, E0=14, dE=2)

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
radius	m	Radius of circle in (x,y,0) plane where neutrons are generated.	0.1
yheight	m	Height of rectangle in (x,y,0) plane where neutrons are generated.	0
xwidth	m	Width of rectangle in (x,y,0) plane where neutrons are generated.	0
dist	m	Distance to target along z axis.	0
focus_xw	m	Width of target	.045
focus_yh	m	Height of target	.12
E0	meV	Mean energy of neutrons.	0
dE	meV	Energy half spread of neutrons (flat or gaussian sigma).	0
lambda0	AA	Mean wavelength of neutrons.	0
dlambda	AA	Wavelength half spread of neutrons.	0
flux	1/(s*cm**2*st*energy unit)	flux per energy unit, Angs or meV if flux=0, the source emits 1 in 4*PI whole space.	1
gauss	1	Gaussian (1) or Flat (0) energy/wavelength distribution	0
target_index	1	relative index of component to focus at, e.g. next is +1 this is used to compute 'dist' automatically.	+1

AT (	,	,		) RELATIVE		Generate
ROTATED (	,	,		) RELATIVE

Links

• Source code for Source_simple.comp.

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[ Identification | Description | Input parameters | Links ]

Generated on 2025-05-08 13:31:31

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Last Modified: Monday, 30-Jun-2025 11:05:10 CEST