Limited Streamer Tubes

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Limited Streamer Tubes

• Mechanical Design Review

William Sands , Princeton
University, 10-21-03
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Overview

• The Limited Streamer Tube (LST) has been used in
  experiments around the world with great success
  as a particle detector. This is not a new
  technology and its proven effectiveness in other
  experiments was a leading reason for the LST
  being chosen for RPC replacement in BaBar.
• The individual LST will be referred to as a tube
  and an assembled set of two or more will be
  referred to as a module.
• The tube will be built at Pol Hi Tech in Italy
  and after extensive testing will be sent to the
  U.S. for assembly at Ohio State University and
  Princeton University.
• It will take 1164 tubes to make 564 modules to
  populate the needed layers in all sextants.

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Basic LST Components
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Basic Handling

• The tubes and modules will always be
  handled out of boxes and fixtures with there
  x-axis vertical for greatly increased strength
  against deflection. Although they are very long
  and made of PVC they are quite robust especially
  as a module.

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Assembly of Modules

• Modules will be assembled in fixtures such as
  shown here. The individual parts will be bonded
  with a 2 part epoxy made by Shell ,using Epon
  resin 815C and Epi-Cure 3140 as the hardening
  agent.

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Assembly Procedure Diagram
The PHI strip is placed in the fixture and
epoxy is applied, then epoxy is applied to the
inner sides of the tubes and rib prior to being
set on the PHI strip and hold downs placed on.
After curing the fixture is pivoted vertical for
module removal.
The stainless rib is placed in the module to
assist in the rigidity of the module when the
x-axis is in the horizontal position in the
magnet. The rib will help overcome any anomalies
in the magnet steel.
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Shipping ,Testing and Installation
Box

• From the gluing fixture the module is moved
  to a specialized box deemed the H-box because of
  its shape. The box will be constructed in Italy
  and shipped to the U.S. with tubes inside and
  then be able to accept modules for testing and
  shipping.

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H-Box Properties
As long as only the top is removed the H-Box
remains very resistant to deflection and prop
twist. After testing one side the top is replaced
and the box is flipped to access the other side.
The aluminum foil is in place for testing
purposes.
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Conclusion

• Spare tubes and modules will be built but
  with extensive testing and quality control these
  should be at a minimum.
• The overall structure of the tubes and the
  modules are simple and robust making them a
  reliable detector for BaBar.