The CMS all silicon tracker (upper picture) covers a total area of 210 square meters with 15232 detector modules. It is by far the largest silicon strip detector ever built. It consists of 10 barrel layers and two times nine end cap layers inside a volume of about 5.4 m length and 2.4 m radius. One of the biggest challenges in constructing and building the CMS silicon strip detector is its operation temperature at -20 degree celsius.

In numbers:

1. •223 m2 of silicon sensors 
   

2. •6000  thin  sensors, 20 000 thick sensors
   

3. •26 million Bonds  
   

4. •10 million strips <=> electronics channels 
   

5. •78 000 APV chips
   

Our group is involved in the construction of the tracker endcaps (TEC). The support structure of one tracker endcap (lower picture) has been delivered in November 2005 from Aachen to CERN.