[ Identification | Description | Input parameters | Output parameters | Links ]

The Sapphire_Filter Component

Sapphire filter at 300K

Identification

• Author: Jonas Okkels Birk (based upon Filter_Graphite by Thomas C Hansen (2000))
• Origin: PSI
• Date: 6 December 2006
• Version: 1.1.1.1

Description

This sapphire filter, defined by two identical rectangular opening apertures,
is based upon an absorption function 

absorp=exp(L*A+C*(exp(-(B/L^2+D/L^4))))

decribed by Freund (1983) Nucl. Instrum. Methods, A278, 379-401. 

Default values are for Sapphire at 300K as found by measurement (Mildner &
Lamaze (1998) J. Appl. Cryst. 31,835-840 

The transmission in sapphire only depends slightly on temperature.
The above formula has only been verified at wavelenths between 0.5 and 14 AA (0.4 meV 0.3
eV).

A filter of this type is used in the Eiger beamline at PSI to cut of high energy neutrons.

WARNING: This is a contributed Component.

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
xmin	m	Lower x bound (-0.16)
xmax	m	Upper x bound ( 0.16)
ymin	m	Lower y bound (- 0.16)
ymax	m	Upper y bound ( 0.16)
len	m	Thickness of filter ( 0.10)
A	m^-1 AA^-1	Material constant	0.8116
B	AA^2	Material constant	0.1618
C	m^-1	Material constant	21.24
D	AA^4	Material constant	0.1291

Links

• Source code for Sapphire_Filter.comp.

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[ Identification | Description | Input parameters | Output parameters | Links ]

Generated automatically by McDoc, Peter Willendrup <peter.willendrup@risoe.dk> / Fri May 11 08:41:09 2012

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Last Modified: Friday, 11-May-2012 10:41:09 CEST