[ Identification | Description | Input parameters | Links ]

The FZP_simple Component

Fresnel zone-plate as a thin object approximation.

Identification

• Site:
• Author: A Komar Ravn, and Erik B Knudsen
• Origin: NBI/DTU
• Date: Aug, 2015

Description

A simple phenomenological thin-object approximation of a Fresnel Zone Plate.
This component was adapted for neutrons from the original component
written for helium scattering.
The focal length of the Zone Plate is determined by the formula:
\[f = 2*r*dr/(lambda)\]
If a diffraction order other than 1 is wanted the focal distance is scaled accordingly.

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
rad	m	Radius of the zone-plate.
dr	m	Width of the outermost ring-slit.
bs0rad	m	Radius of the central blocking zone.	0
order	m	Use this diffaction order.	1
eta		Efficiency of the FZP. For neutrons and (order==1) typically {5...30}%. Overrides the sigma_x cross sections.	0.1
sigma_abs	barn	2200 m/s absorption cross section.	0
sigma_inc	barn	Incoherent scattering cross section.	0
sigma_coh	barn	Coherent scattering cross section.	0
rho			1
thickness	m	Thickness of the FZP. Note that the FZP still is modelled as a thin object. The thickness is used in conjunction with the sigma_x cross sections.	0
gamma		Duty cycle of the Zone plate - used merely for absorption estimation.	0.5

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

Links

• Source code for FZP_simple.comp.

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[ Identification | Description | Input parameters | Links ]

Generated on mcstas 3.5.32

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Last Modified: Monday, 30-Jun-2025 11:05:09 CEST