thoughts for fdc design backup

[Elton Smith <elton@jlab.org>]

HI David,

I have tried to outline my thoughts in a "one slide" justification for the
FDC design selection. It might be useful for backup.

Thoughts?


FDC Design Selection:

Requirement: Full coverage of downstream area required by physics (full
phi-range).
-> implies the need for large-angle stereo to achieve good position
resolution in all directions
   -> creates large number of ghost hits

Solution: Add cathode planes to identify space points locally.
This is achieved by
1. tight timing cuts between cathode planes and hit wire because they see
the same avalanche.
2. Two cathode planes (on either side of the wire) can be used at the hit
level to identify the matching wire.



Elton Smith
Jefferson Lab MS 12H5
12000 Jefferson Ave
Suite # 16
Newport News, VA 23606
elton@jlab.org
(757) 269-7625
(757) 269-6331 fax