Re: Geometries for 2008 DC Review

[Matthew Shepherd <mashephe@indiana.edu>]

Hi Mihajlo and Dave,

On Jan 24, 2008, at 12:06 PM, David Lawrence wrote:

> I do see the positions and heights of the peaks have changed quite  
> a bit. But, not so much so that I expect to see as flat of a  
> distribution as I see in your plots. I could be wrong though, but  
> I'm hoping when you re-run with the exact geometries I'm using, we  
> sill consistent pictures.

I suggest Mihajlo generate plots of both conversion probability and  
efficiency to provide a definitive answer since I suspect the  
confusion is in the distinction between these two.  Attached are  
similar plots for only the current geometry.  Conversion probability  
is directly related to David's radiation length scans, but efficiency  
is not necessarily since converted photons can be reconstructed if  
secondary particles still form a nice cluster.  You can get an idea  
of the magnitude of this effect by comparing the attached plots.  In  
the ring region the efficiency is up around 85-90% but the conversion  
probably is still in the 20-30% range.

-Matt

eff_conv.pdf