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A proposed stave design for the D0 Run IIb silicon tracker outer layers featuring central cooling channels and a composite shell mechanical structure is evaluated for self-deflection and deflection due to external loads. This paper contains an introduction to the stave structure, a section devoted to composite lamina and laminate properties and finally a section discussing the beam deflections expected for assembled staves using these laminates.

A proposed stave design for the D0 Run IIb silicon tracker outer layers featuring central cooling channels and hybrid substrates mounted directly to the silicon sensor surfaces is evaluated for heat transfer characteristics and thermal deflections. In order to control leakage current noise in the silicon it is necessary to maintain the silicon in Layer 2 (R {approx} 100mm) at or below +5C. The current cooling system using 30% ethylene glycol in water can deliver coolant to the inlet of the silicon tracker at a temperature of -8C to -10C. This paper also investigates some alternative coolant options for Run IIB. While these are not required for the outer layers of silicon, they may be needed for L0, which sits at R {approx} 15mm. In this case the silicon must be kept at or below -5C, very near the lower limit for delivery of 30% glycol/water coolant. However, for the inner layers the electronics will be mounted independently from the silicon so the local heat flux is greatly reduced. This paper does not consider the cooling issues for the inner layers.