1. 1 Welcome to the mini-review of the Roman Pot mechanics for the ALFA project in ATLAS

2. 2 Some points to start with….. Discuss and compare two different solutions to of a mechanical “conflict” problem Consider both mechanical aspects and LHC vacuum aspects of the two solutions If possible also try to include financial and realization time aspects of the two solutions. “Brain storming” meeting that is do not hesitate to interrupt speakers in order to object and ask questions Remember : A “stupid” question might turn out to be important But first s a short introduction to the project for the outsiders……

3. 3 ATLAS Roman Pots Goal: Determine absolute luminosity at IP1 (2-3% precision) Measure elastic rate dN/dt in the Coulomb interference region (à la UA4). |t|~0.00065 GeV 2 or Θ ~ 3.5 microrad. RP IP RP This requires (apart from special beam optics) to place detectors ~1.5 mm from LHC beam axis to operate detectors in the secondary vacuum of a Roman Pot spatial resolution s x = s y well below 100 micron (goal 30 micron ) no significant inactive edge (< 100 m icron)

4. 4 Roman Pot locations

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6. 6 Overlap extrusions brazed on bottom Top flange Pumping hole Rectangular body out of center Brazing under test S.Mathot (TS- MME) The Pot First prototype being prepared Will soon be vacuum tested Simulation of contribution to the impedance budget ongoing

7. 7 The detectors-fiber tracker Choice of technology: minimum dead space no sensitivity to EM induction from beam resolution  ~ 30  m Concept 2x10 U planes 2x10 V planes Scintillating fibers 0.5 mm 2 squared 64 fibers per plane Staggered planes MAPMT readout

8. 8 Complete detector for one Roman Pot i.e. 1460 channels

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11. 11 8-1 i.e. left side +26 mm -33 mm

12. 12 1-2 i.e. right side -32 mm -3 mm

13. 13 +26 mm-33 mm -32 mm -3 mm IP Left Right Install a normal station here Install slightly modified station here Modified station here in 2010

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15. 15 Back up

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