VELO Module Metrology

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VELO Module Metrology

• Girish Patel
• John Carroll

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Alignment in X Y
Girish Patel John Carroll
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Module Metrology
Relative alignments between R and Phi
sensors measured on Smartscope (Sms) and CMM
show reasonable agreement
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Module Metrology
Differences of the above show that Smartscope and
CMM agree to -10 microns, apart from 3 modules
(M30,M32,M37)
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Module Metrology
Absolute positions of centre of Si from CMM for R
LHCb x is within 20 micron tolerance LHCb y
still needs to be reduced
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Module Metrology
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Module Metrology
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Module Metrology
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Module Metrology
Absolute R and P rotations from CMM. Show a
systematic offset from zero of -0.24 mrad. with a
standard deviation of 0.06 mrad. Need to bring
the systematic down towards zero.
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Silicon Alignment
Module Metrology
Average STD R to Phi alignment
(X,Y) -0.001,-0.003 0.007,0.016 R absolute
(X,Y) -0.002,0.016 0.008,0.010 R to Phi
rotation (mrad) 0.041 0.044 R absolute
(mrad) -0.238 0.059
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Pedestal Mounts
Module Metrology
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Module Metrology
Alignment in Z
John Carroll Girish Patel
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Module Metrology
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Module Metrology
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Mod met
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Module Metrology
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Module Metrology
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Top of Silicon Envelope
Module Metrology
Average STD Separation envelope
2.29 0.1 Twist mm 0.02 0.25 Tilt mm
0.08 0.06 Forward edge 1.16 0.27 Rearward
edge -1.12 0.23 --------------------------------
---------------------------------- Envelope Nomin
al Worst case Forward 1.15
1.767 Backward -1.15 -1.654
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Module Metrology
Proposed Constraint System