[ Identification | Description | Input parameters | Links ]

The SANS_spheres2 Component

Identification

• Site:
• Author: P. Willendrup, derived from H. Frielinghaus SANS_benchmark2
• Origin:
• Date: 16.12.2019

Description

Sample for Small Angle Neutron Scattering - hard spheres in thin solution, mono disperse.

For the scattering simulation a high fraction of neutron paths is directed to the scattering (exact fraction is sc_aim).
The remaining paths are used for the transmitted beams. The absolute intensities are treated accordingly, and the p-parameter is set accordingly.

For the scattering probability, the integral of the scattering function between Q = 0.0001 and 1.0 AA-1 is calculated.
This is used in terms of transmisson, and of course for the scattering probability.
In this way, multiple scattering processes could be treated as well.

The typical SANS range was considered to be between 0.0001 and 1.0 AA-1.
This means that the scattered neutrons are equally distributed in this range on logarithmic Q-scales.

Example: SANS_spheres2(xwidth=0.01, yheight=0.01, zthick=0.001, model=1.0, dsdw_inc=0.02, sc_aim=0.97, sans_aim=0.95, R-150)

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
xwidth	m	Width of sample volume	0.01
yheight	m	Height of sample volume	0.01
zthick	m	Thickness of sample volume	0.001
dsdw_inc	cm^-1	The incoherent background from the overall sample, should read ca. 1.0 for water, 0.5 for half D2O, half H2O, and ca. 0.02 for D2O	0.02
sc_aim	1	The fraction of neutron paths used to represent the scattered neutrons (including everything: incoherent and coherent). rest is transmission.	0.97
sans_aim	1	The fraction of neutron paths used to represent the scattered neutrons in the sans-range (up to 1.0AA-1). rest is incoherent with Q>1AA-1.	0.95
R	AA	Radius of dilute, monodisperse spheres	150
phi	1	Volume-ratio of the spheres wrt. solution	1e-3
drho	cm^-2	Scattering length density	6e10
singlesp	1	Switches between multiple scattering (parameter zero 0.0) and single scattering (parameter 1.0). The sc_aim directs a fraction of paths to the first scattering process accordingly. The no. of paths for the second scattering process is derived from the real probability. Up to 10 scattering processes are considered.	1
Qmind	AA^-1	Lower limit of "SANS" scattering	0.0001
Qmaxd	AA^-1	Upper limit of "SANS" scattering	2.1544346900319

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

Links

• Source code for SANS_spheres2.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