Region 2 Drift Chambers

1
Region 2 Drift Chambers

• Status Report
• Qweak Collaboration Meeting
• March 2006

2
First prototype
3
(No Transcript)
4
New chamber

5
(No Transcript)
6
New chamber
7
Design Parameters

• Active area 30cm x 45cm
• Wire pitch 4.65 mm
• 20 micron gold-plated Tungsten sense wires
• 75 micron gold-plated Be-Cu field wires
• Load on the frame due to wires is 4.3 lb
• Four chambers with six planes each (xuvxuv)
• (u and v wires at 56o)
• 1408 electronics channels
• Nanometrics preamp/descriminators
• 100 x 16 channels/board 31.5k

8
Cleanroom
9
Cathode plane

• Cathode plane

10
Stringing X plane

• Stringing X plane

11
Stringing V plane

• Stringing V plane

12
Wire scanning

• Wire scanning

13
Wire scanning

• Wire scanning

14
Wire scanning

• Height gage least count is 10 microns
• Standard deviation of repeated measurements of
  the same wire is 15 microns
• Gravitational sag of wires should be less than 15
  microns
• Standard deviation of measured location from
  nominal location is 37 microns
• Goal is to know the wire locations to better than
  50 microns

15
(No Transcript)
16
(No Transcript)
17
Status

• Design complete
• Two planes strung (third next week)
• Power supply for amplifiers ordered (1k)
• 15 more Nanometrics cards ordered (5k)
• (have 10 - need 22 to read out a
  complete chamber)

18
What we learned about construction time

• Machining of two window frames, four cathodes and
  three sense planes took two weeks.
• Stringing takes about 5 hours per plane.
• Wire scanning takes about 3 hours per plane
• gt production time is approximately one month
  per chamber.

19
Schedule

• 2006
  
  2007
• March April May June July Aug
  Sept Oct Nov Dec Jan.
• test a half chamber Add xuv
  Track cosmics Start
• (xuv sense planes) (xuvxuv planes)
  and measure spatial production
• try 20 CO2 80 Argon resolution
• 10 CO2 2 CH4 88 Argon