1. VELO Replacement Girish Patel University of Liverpool

2. G.D. Patel University of Liverpool2 LHCb The VELO detector is essential to the running of the LHCb experiment. The collaboration took the decision that a replacement was required to mitigate against risk from a beam accident (2007) and contributed 800 KSFr. LHCb - Forward coverage, high precision tracking and vertexing, excellent PID  Perfect tool for particle production studies in the forward region

3. G.D. Patel University of Liverpool3 VELO Modules The replacement modules are identical to the original except that sensors were switched to n-in-p from the original n-in-n for greater radiation tolerance and the kapton pitch adaptors were replaced with glass ones. Module production was managed by Torkjell.

4. 46 modules completed and shipped to CERN, 42 have been installed and cabled onto the two replacement halves with significant Liverpool technical effort. Karol has managed the installation and setup a slice of the full LHCb DAQ for electrical testing. VELO Replacement 4G.D. Patel University of Liverpool

5. VELO Replacement Tasks  Complete Assembly o First half completed. o Complete testing modules of 2 nd halfJune o Thermaflow and full testing to check cooling performanceJuly Tony + Torkjell + Karol (no workshop effort)  Full Metrology of both halves o Three weeks booked from Sept 17 th Sept o Analysis of metrology data  define silicon position  check base plate Girish + CERN effort (no workshop effort) 5G.D. Patel University of Liverpool

6. 6 VELO Replacement Tasks Display/Storage  Module installation onto base plate takes place on mounting trolley.  Leave mounted on installation trolley/frame.  Need transparent cover with flange that seals against base plate  Rotate through 90⁰ to LHCb orientation  Box off trolley and all support structure so only mounted modules visible through transparent cover  Ready for Nov/Dec this year. Design effort ~1 week (JLC) + Workshop fabrication ~1 week (1 FTE)

7. VELO Replacement Installation De-Installation / Installation procedures o Need to talk to NIKHEF and CERN about previous installation o Reverse procedure for de-installation  care required due to activation – Radiation Protection Rules o Remove and store old VELO in RP area o Insert replacement and cable. VELO working well and does not need to be replaced However, procedures will be complicated and require a lot of time and effort should it become necessary to install the replacement. We estimate that it would need 2 workshop staff over 3 months + members of the group with help from NIKHEF and CERN to remove the old VELO and install the replacement. 7G.D. Patel University of Liverpool