1. Lukens - 1 Run IIb Project Motivations Integrated luminosity or duration of the run motivates us to  Replace the silicon detector - Radiation damage to inner layers, optical interconnects - SVT trigger – new silicon implies new trigger hardware  Replace level 2 processors - Running to 2008-09 with the Alpha is not wise  Replace Level 3 processors - Running to 2008-09 with 500 Mhz. Instantaneous luminosity of Run IIb motivates us to  Replace TDCs - Data rate bottleneck at 300 Hz  Replace Event Builder - Data rate bottleneck at 300 Hz  Replace XFT - Track fake rate at high occupancy  Replace Preshower - Last accessible piece of gas calorimetry. Long memory is swamped by occupancy.

2. Lukens - 2 CDF costs at level 3 Costs broken down by subproject  Red – integrated luminosity  Blue – instantaneous lum.

3. Lukens - 3 Run IIa/IIb Layout Comparison Run IIb Detector was designed for high occupancy  90 0 layers were abandoned – 3 layers was the maximum, and these aren’t robust  Extra axial layers were substituted for redundancy  Detector spacing is more diffuse – reduction of long extrapolations into “busy” areas  Pattern recognition is more robust in a high rate environment.