[ Identification | Description | Input parameters | Links ]

The Source_div_quasi Component

Quasi-stochastic neutron source with Gaussian or uniform divergence

Identification

• Site:
• Author: Mads Carlsen and Erik Bergbäck Knudsen (erkn@fysik.dtu.dk)
• Origin: DTU Physics
• Date: Jan 22

Description

A flat rectangular surface source with uniform or Gaussian divergence profile and focussing.
If the parametere gauss is not set (the default) the divergence profile is flat
in the range [-focus_ax,focus_ay]. If gauss is set, the focux_ax,focus_ay is considered
the standard deviation of the gaussian profile.
Currently focussing is only active for flat profile. The "focus window" is defined by focus_xw,focus_yh and dist.
The spectral intensity profile is uniformly distributed in the energy interval defined by e0+-dE/2 or
by wavelength lambda0+-dlambda/2

The phase space spanned by the generated neutrons is sampled by means of Halton-sequences, instead of regular
pseudo random numbers. This ensures that samples are evenly distributed within the phase space region of interest.

Example: Source_div_quasi(xwidth=0.1, yheight=0.1, focus_aw=2, focus_ah=2, E0=14, dE=2, gauss=0)

%VALIDATION

%BUGS

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
spectrum_file		File from which to read the spectral intensity profile	""
xwidth	m	Width of source	0
yheight	m	Height of source	0
focus_xw	m	Width of sampling window	0
focus_yh	m	Height of sampling window	0
dist	m	Downstream distance to place sampling target window	0
focus_aw	rad	Std. dev. (Gaussian) or maximal (uniform) horz. width divergence	0
focus_ah	rad	Std. dev. (Gaussian) or maximal (uniform) vert. height divergence	0
E0	meV	Mean energy of neutrons.	0
dE	meV	Energy spread of neutrons.	0
lambda0	AA	Mean wavelength of neutrons (only relevant for E0=0)	0
dlambda	AA	Wavelength half spread of neutrons.	0
flux	1/(s*cm**2*st*energy unit)	Flux per energy unit, Angs or meV	0
gauss	1	Criterion: 0: uniform, 1: Gaussian distribution of energy/wavelength	0
gauss_a	1	Criterion: 0: uniform, 1: Gaussian divergence distribution	0
randomphase		When=1, the X-ray phase is randomised	1
phase		Set to finite value to define X-ray phase (0:2 pi)	0
verbose		Generate more output on the console.	1

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

Links

• Source code for Source_div_quasi.comp.

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[ Identification | Description | Input parameters | Links ]

Generated on 2023-09-19 20:01:36

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Last Modified: Tuesday, 17-Sep-2024 05:31:14 CEST