february 2003 pixel support tube a. smith lbnl 1 atlas pixel support tube prr: parts pixel support...

FEBRUARY 2003Pixel Support Tube A. Smith LBNL 1

ATLAS Pixel Support Tube PRR: Parts

Pixel Support Tube Production Readiness Review Parts Overview

Alexis SmithFebruary 18, 2003



Overview

Schematic of Pixel Support Tube assemblyList of PartsMethod of production for each part• Materials• Tools• Lay-up procedure• Cure procedure• Pre-assembly processingComparison of prototype to production parts



Schematic of PST Assembly

• The Pixel Support Tube Assembly comprises the shell, the rails on which the pixel detector slides, the mount connections to the SCT, and the thermal isolation system



List of Parts

• PST Shell Laminate– Forward Shell (2)– Barrel Shell (1)

• PST Flange Assembly– Flange (6)– Backing Ring (6)

• Mount Pad (6)• Flat Rail (9)• Vee Rail (3) • Hoop Stiffener (57)

• Heater System Assembly – Heaters (108)– Mount Pad Circuits (6)– Wires (357)

• Various machined and other parts– Pixel mount– Mount block– Mount insulator shim– Mount insulator pad– Wire harness– Adhesive – Connector

• (Flexures)



Shell Laminate

• Fiberglass mat, EX1515U, [0,0,+60,-60]S

• 8-ply symmetric lay-up of YSH-80 (carbon) and AQ-II (fiberglass) with a layer of fiberglass mat to prevent carbon particle liberation

• Plies are cut to allow for axial and circumferential interweaving

0 degree

60 degree

-60 degree

-60 degree(2nd layer



Shell Laminate

• 0 plies laid-up separately and with tension

• -60 and +60 plies stacked and pre-compacted before lay-up

• Stack is compacted on mandrel after each new layer application

• Heater panels layed-up as last step before cure

• Prototype: plies interleaved in the hoop direction

• Production: plies interleaved in hoop and axial directions



Shell Laminate

• Production mandrel will be 2500 mm long• Production shell laminates shall be 457.5 mm OD• Barrel shell length: 1631 mm• Forward shell lengths: 2276.5



PST Flange Assembly: Flange

• [+/-45, +/-45, +/-45]• 3-ply involute lay-up of CN60 strips with 2/3 overlap of

each strip• Lay-up on flange tool with collar



Trimming of Flange

• Flange lip is trimmed to size with a router on a trim plate



PST Flange Assembly: Backing Ring

• [0/90,+/-45, 0/90,+/-45, 0/90,+/-45, 0/90,+/-45]S

• 16-ply lay-up of CN60 cloth in alternating orientations• Total post-cure thickness is 4 mm• Lay-up a large ring out of which the backing ring is cut



Trimming of Backing Ring

• Water-jet cut backing ring out of large lay-up• Cut bevel with router on the same trim plate as the

flange



Mount Pad

• [0/90,0/90,+/-45, +/-45, 0/90,+/-45, 0/90, +/-45, +/-45, 0/90,0/90]

• 11-ply quasi-symmetric lay-up of CN60 cloth• Darts are used to ensure proper conformance to tool

shape



Mount Pad

• Part is trimmed on a custom vacuum chuck



Flat and Vee Rail

• EX1515, [0/90, 0/90, 0/90, 0/90, 0/90, 0/90, 0/90]• 1 ply of EX1515 followed by 7 plies of P30 cloth• Stacks of 3-4 plies are pre-compacted before being

layed-up• Part trimmed to length on the tool• Tool is supported during cure to minimize out-of-

straightness



Hoop Stiffener

• [+/-45,0/90,+/-45]• 3-ply CN60 lay-up• Dart to ensure proper conformance to tool shape• Made in 3 parts



Heater Panel

• Custom-made part supplied by vendor

• Kapton with copper sputter-coated on both sides, Aluminum foil on one side, polymer coverlay on the other side. Heater traces and connection pads etched onto copper.

• 4 positive leads and 1 negative to allow for multiple connection possibilities

• Connection points for EMI shielding

• Jumper across mount pad area



Heater Panel

• Shell with co-bonded heater panels



Flexure Mounts

• 3 Flexures, 1 Solid Block• Made of Titanium• Still in design phase



Machined and Other Parts

• Pixel mount• Mount block• Mount insulator shim• Mount insulator pad• Wire harness• Adhesive (Hysol 9396)• Connector



Comparison of Prototype to Production Parts

• Successfully built all composite parts except hoop stiffeners– Shell laminate with heater panels– Flange and backing ring– Flat and Vee rails– Mount pads

• Length of shell prototype is shorter and shell lay-up method is slightly different. Plies will be the same.

• All other components are equivalent to production parts.

february 2003 pixel support tube a. smith lbnl 1 atlas pixel support tube prr: parts pixel support...

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