dimensions

[Elton Smith <elton@jlab.org>]

Detector dimensions

Curtis recently sent around a list of detector dimensions. Ravi reviewed 
some of the differences from that list and his model, most of which are 
due to recent updates. For the record, I briefly summarize the differences 
here.

1. Iron fills the gap between coils.
2. 6" of Fe has been added to the downstream edge of the magnet to improve 
magnetic properties.
3. The FDC packages are wider, consistent with prototype dimensions.

Due to #2, there was some discussion about where the barrel calorimeter 
actually ends: should it go all the way to the end of the iron, or (more 
likely) end shortly past the last FDC package. Ed was going to review this 
with George and Zisis. (This discussion lead to the question as to where 
the barrel calorimeter should start as well. Currently the drawings have 
it starting at the upstream edge of the CDC.)

Ravi also questioned the location of the origin, which we thought to be at 
the upstream edge of the magnet iron. However, this point seems to be 
inconsistent with some of the dimensions that Curtis gave. Ravi should 
check this out with Curtis.

Cheers, Elton.


-- 
Elton Smith
Jefferson Lab
elton@jlab.org
(757) 269-7625