Re: one-magnet tagger counters

[Richard Jones <richard.t.jones@uconn.edu>]

Franz,

Thanks for these.  However I may not understand your coordinate system.  
I also don't understand Yang's even after a couple of email exchanges, 
so it does not help me to reference yours to Yang's.  I think Yang is 
using a left-handed coordinate system, which adds to my general state of 
confusion.  Either we need to distribute a sketch every time we share 
coordinates, or else we should agree on a common set of coordinates that 
we all use.  I favor the latter.

Let's define things in terms of the master reference system, with the 
origin on the beam axis at the entrance to the diamond, z along the 
beam, and y pointing up, and x given by the right-hand rule.  If you can 
give me the coordinates of counter #1 in this reference system, and the 
final rotation angle of the FP with respect to the photon beam 
direction, I think I can understand that!  After that, we need to figure 
out where the magnet is, then I think we can do a simulation.

With the additional endpoint counters, there are 190 counters in the 
fixed array.  At some point, this  update should be communicated to the 
online team who are keeping track of channel counts.

Richard J.

Klein, Franz wrote:
> Richard,
> attached is a file with counter positions on FP (scen) and with 30cm displacement (xcen, as used in construction design).
> FP is rotated by 6.07deg w.r.t. Yang's coordinate system, its origin is the upstream edge of the magnet,  
> The first 10 counters (counter number negative) are the extension ... actually up to 10.7GeV.
>
> Greetings
>
> Franz
>
>
>