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

The Sapphire_Filter Component

Sapphire filter at 300K

Identification

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


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

Generated automatically by McDoc, Peter Willendrup <peter.willendrup@risoe.dk> / Fri Feb 11 10:12:09 2011