Pixel Detector Beampipe Support Frame ATLAS Longerons Wire

Pixel Detector Beampipe Support Frame ATLAS Longerons Wire Adjustors Service panel Attachment points Fixed Adjustors (no spring) Top and Side Reinforcing Longerons Wires at Z=-800, +800 Sprung Adjustors Side and bottom (tension limiters) Cruciform supports April 2002 VI Beampipe FDR N. Hartman LBNL

Pixel Detector ATLAS Geometry at Pixel Detector End Longerons Wire Guide Cruciform Support No BP Collar Shown Beampipe April 2002 VI Beampipe FDR Beampipe shown in extreme off-center position N. Hartman LBNL

Pixel Detector ATLAS Adjustor/Tension Limiter Wire Guide Preload Adjustor Barrel Wire Adjustor Nut Wire Collet & Nut Tension Limiter Plunger Limiter Spring Wire Adjustor Screw April 2002 VI Beampipe FDR N. Hartman LBNL

ATLAS Pixel Detector Assembly of Adjustor/Limiter Unit Tension Limiter Assembled, Spring Compressed Wire Fed Through, Clamped into Collet Wire Adjustor Seated in Tension Limiter Max “IN” Adjustment April 2002 VI Beampipe FDR Max “OUT” Adjustment N. Hartman LBNL

Pixel Detector ATLAS Tension Limiter During Operation, Spring Holds Limiter Plunger Against Preload Adjustment Barrel When Tension Limit is Exceeded, Plunger Moves, Allowing Wire to Extend Under Reduced Stiffness of Spring Electrical Contact Between Plunger and Adjustment Barrel (not shown) signals when Tension Limit is Exceeded. April 2002 VI Beampipe FDR N. Hartman LBNL