Date: Fri, 03 Sep 2004 14:11:03 -0500
From: Jim Birchall
To: Juliette Mammei , Roger Carlini ,
Klaus Grimm , Mark Pitt ,
Neven Simicevic , Greg Smith ,
Dave Mack , Norman Morgan ,
Mike Finn , David Armstrong ,
Yongguang Liang ,
Allena Opper ,
Shelley Page , Tony Forest
Subject: Ultimate limit on azimuthal acceptance
Parts/Attachments:
1 Shown 26 lines Text
2 OK 11 KB Application
3 OK 11 KB Application
4 OK 12 KB Application
5 Shown 1 lines Text
6 OK 6.4 KB Application
7 OK 5.3 KB Application
8 OK 5.8 KB Application
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Here are some results showing the gap between adjacent moustaches
inside QTOR as a function of the phi acceptance of the collimator to
see what would be the ultimate phi acceptance, assuming the coil
supports are out of the way and and an appropriate design can be found
for the Cerenkov bars. Results are based on adaptations of the Boston
collimator 10-8-xx in the terminology of my report discussed at the
September 2 conference call. This corresponds to extreme angles of 6
and about 14.5 degrees out of the collimator.
I placed detector planes at z=0 (QTOR centre), 45, 90, 135, 185 cm
(QTOR exit). According to a recent diagram from Stan Sobczynski, the
outer edge of the coils is 165 cm from the beam axis and the double
pancakes of coils are 11.9 cm thick. To allow 2 cm between the edge of
a moustache and a coil, the gap between moustaches should be no less
than 15.9 cm.
The first 3 pdf files (gap28.pdf, gap30.pdf, gap32.pdf) show the
distribution of events across the edges of two neighbouring moustaches
at the 5 points in the magnet for r < 165 cm.
The second three files (wid28.pdf, wid30.pdf, wid32.pdf) show the gap
between moustaches as a function of z for r<165 cm. A phi acceptance of
32 degrees is too large, 30 degrees is perhaps just acceptable.
Jim
Jim's attachments:
gap28.pdf
gap30.pdf
gap32.pdf
wid28.pdf
wid30.pdf
wid32.pdf