AGENDA

1
Features and Mysteries of BOL chambers

• AGENDA
• Xray tomograph -BOL0 results (Martin)
• BOL0 and BOL2 Features (Graziano)
• Discussion (All)

2
BOL0 - Hypothesis

• OBSERVATIONS BOL0
• Y-pitch between inner wire-layers 20um too large
• Y-Pitch between outer wire-layers only slightly
  too large
• Y-Pitch between multilayers 75um too small

• Hypothesis
• Glue shrimp between tubes and spacer?
• (2x500um glue gap)
• --gt measured lt5um effect for 1mm gap
• Xplate deforms during gluing. In particular the
  flange
• --gt presented today
• Additionally
• Re-analysis of BOL0 construction RASNIK readings
  cumulative effects lead to better agreement!

s
3
Floppy Xplate wrt tubes
Rotation of unknown relative size
_at_longbeam
Longbeam constraints body Xplate locally
Tube-length bends body
Tube direction bends flanges
Away from longbeam
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4
Sag Adjustment
Rotation of unknown relative size
Longbeam constraints body Xplate locally
Tube-length constraints flanges
Tube direction bends flanges
Away from longbeam flange bends differently!
BOL0 is scanned with sag-adjustment (partially)
on! (Longbeam sag is assymetric in BOL0)
When we are optimistic deformation is symmetric
for up/down ML.
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5
Sag Compensation
Rotation of unknown relative size
Longbeam constraints body Xplate locally
Tube-length constraints flanges
Tube direction bends flanges (temporary)
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6
XP deformation
During BOL2 construction, the flange of the HV
xplate was measured with micro-gauges LBF
Longbeam- Flange BF Body- Flange
For now, BOL2 is still equipped with gauges,
located on the inner side of the HV-xplate
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7
Gluing BOL-0

• Stability Xplates during gluing

Layer 1
Yrasnik2 x Sag
Layer 1 dSag7um
Layer 2
Start glue
Layer 3
Layer 2 dSag10um

• The sag of the xplates in layer 1 and 2 change in
  time.
• Layer 3,4,5,6 Sag stable

s
8
Sag Compensation
BOL2
Layer 1
Start -15/2 um

• During gluing of
• layer 1 and 2, significant changes in xplate sag
  were observed
• In-stable reduction valves?
• Effect of glue viscosity?

End -38/2 um
Layer 2
Start 30/2 um End 50/2 um
1 deg
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9
Conclusions

• OBSERVATIONS BOL0
• Y-pitch between inner wire-layers 20um to large
• Y-Pitch between outer wire-layers only slightly
  to large
• Effects largely explained by RASNIK measurements
  during construction.
• Flange deformation of order 10um could be
  baked in.
• Y-Pitch between multilayers 75um to small
• Flange deformations of this order are certainly
  observed. However these deformations appear
  symmetric and elastic.
• Needs more study -gt effects of kinematic mounts
• direct -in situ- measurement dY of Frascati comb
  and towers

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10
Test _at_CERN inTomograph (BOL0)
Analysis of Martin Woudstra
Wire positions RMS 16mm
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11
Parallelogram-ness
For stability bare spacer
Checks distance wrt Comb _at_ RO side
BOL
RO
rail
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12
Landing-Tool

• Problems with lowering gluing tube layers on tube
  layers due to glue viscosity
• Landing tool pre-aligns chamber and ensures flat
  landing in glue.

BOL
Tower
Effective Easy
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13
Cosmic Ray Stand
s