1. Status VELO alignment 1.Alignment at IP8 Jo van den Brand Frans Mul June 2, 2006

2. CenterFrame Alignment references

3. VELO reference system IP -335785 555 -555 rotu rotm rotd robdrobu Same for the left side right side

4. Coordinates In LHCb Physicist Coordinate System (z-along beam line) x-coordinate includes 20 mm offset from alignment spheres

5. Alignment Center Frame in IP8 Initial installation of VELO was carried out to about 1 mm precision Final alignment required - rotation around z-axis of 0.75 mrad - shift of CF by -0.5 mm in y-direction - rotation around y-axis of 0.30 mrad - shift by +0.25 mm in x-direction Alignment with theodolites (precision ~300  m) Final precision of position in IP8

6. Fitted planes and normal vectors CenterFrame planes within 100  rad parallel Also parallel to beam lines with this accuracy