[neutron-mc] Monochromator_curved parameter

[Peter Willendrup]

Hello Tom,


On Apr 16, 2008, at 3:57 PM, wokaoyan1981 wrote:
> I'm visualizing the double bent crystal monochromator and here is my  
> problem:
>
> What is the suggested value of r0(Maximum Reflectivity) and  
> t0(Transmission Efficiency) for each crystal plane of Si?(The  
> default is 0.7 and 1.0 respectively.) Or where should I manage to  
> obtain the reflectivity and transmision files for each Si(hkl)?

I would suggest you to start out by for example some of these references

Sears et al Acta Cryst. (1997). A53, 35-45 Bragg Reflection in Mosaic  
Crystals. I. General Solution of the Darwin Equations
Sears et al Acta Cryst. (1997). A53, 46-54 Bragg Reflection in Mosaic  
Crystals. H. Neutron Monochromator Properties

Kimura et al NIMA 482 (2002) 799–805 Development of a horizontally and  
vertically focused neutron
monochromator using stacked elastically bent Si single crystals

Or perhaps one of the other McStas users has one or more relevant  
reflectivity profiles to contribute?


Regards,

Peter Willendrup