FLARE Constructing the detector

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FLAREConstructing the detector
Fermilab Liquid Argon Experiments

• First FLARE Workshop
• November 4-6, 2004
• Rafael Silva
• Fermilab / PPD / MD

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• Overall Project Scale (Model by Bartoszeck
  Engineering)

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• Some numbers
• Inner tank
• Height 108 ft 33 m
• Diameter 132 ft 40 m
• Volume 1,500,000 ft3 11,000,000 gal
• 42,000 m3
• Argon density 1.4 Þ total weight 60 kton
• Weight of inner tank cylindrical wall 1.5 kton

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• We can divide the design and construction
  issues in 3 major groups
• Tank
• Detector
• Integration of detector into tank structure

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• Tank issues
• Shape
• Design requirements
• Material
• Insulation

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• Shape
• Double steel wall
• Insulation between walls
• Flat bottom
• Flat roof (short electronics path) or
  self-supporting curved roof

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• CBI double steel wall tank

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• Design requirements
• Roof structure capable of supporting vertical
  wire load of 300 tons
• Side wall capable of supporting horizontal wire
  load of 115 tons

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• Design requirements (cont.)
• Access to electronics on top of roof
• No leaks (from joints)
• No contamination (from internal surfaces)

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• 3D model (Model By Chuck
  Crimm / FNAL)

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• Material
• Normally used 9 Ni alloy steel
• 3 x costlier than regular carbon steel,
• ductile at low temperatures,
• somewhat better corrosion resistance.
• May it be coated?

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• Material (cont.)
• Stainless steel (no atmospheric corrosion)
• 9 x costlier than regular carbon steel,
• ductile at low temperatures,
• may have lower strength (thicker, heavier,
  costlier)

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• Insulation
• Perlite (expanded volcanic glass)
• Normal in place density range between 8 and 9
  lb/ft3

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• Detector
• 6 HV wire sectors,
• 7 cathode planes, and
• field shaping tubes in between them.

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• Detector
• Each wire sector has 6 wire planes oriented at
• 30,
• -30,
• vertical,
• vertical,
• -30, and
• 30, in this order.

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• Layout of wire sectors

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Stereo Planes
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• Field shaping tubes (Model by
  Bartoszeck Engineering)

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• How are the wires held in place?
• Using same method used by Icarus (according to A.
  Para)
• Need to be tested Þ small scale model
• One end is connected to the electronics and the
  other end is connected to the weight

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• Stereo Wires
• These are guided through a system of insulated
  pulleys.
• Preliminary estimates indicate availability of
  space on the sides and at the bottom for the
  pulleys
• Pulleys are staggered and pre-assembled in groups
  to panels to be located by rails attached to the
  tank
• Prototype required

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• Wire analysis
• 150mm dia. stainless steel wire
• Max. wire length 125 ft 38 m
• Wire tension achieved by 1.3kg weight
• Max. stereo wire bowing (deflection) is 0.38 in
  1 cm
• Max. wire elongation 5.4 in 14 cm

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• Integration of detector into tank structure
• Among the options, an analysis was made of the
  flat roof case
• Wire load is supported by space frames (trusses)
  at the top
• Trusses are supported by inner wall
• Inner wall also supports horizontal loads from
  wires

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• 3D model
• space frame detail (Model By Chuck Crimm /
  FNAL)

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• Example loading and wall thickness

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• Example - FEA hydrostatic load only

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• Example - FEA boundary conditions

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• Example - FEA static / max. shear

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• Example - FEA linear buckling / B.L.F.

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• Integration of detector into tank structure
  (cont.)
• Preliminary analysis indicates feasibility of
  flat roof and load supported by inner shell
• More loading cases need to be studied
• Subsequent more detailed analysis is needed

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Fermilab Liquid Argon Experiments
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