1. Philip Burrows MDI Panel Meeting 15/08/06 Philip Burrows John Adams Institute Oxford University SiD and IR/MDI Issues

2. Philip Burrows MDI Panel Meeting 15/08/06 Response to BDS CCB request SiD Advisory Group met 14/8/06 to consider BDS request IR crossing angles: 2/20 -> 14/14 mrad: support with enthusiasm -- downstream monitoring of energy and polarisation -- control of backgrounds with anti-DID -- small loss of acceptance for (some) SUSY searches Single IR hall at z=0 shared by both detectors: acceptable -- concerns about mechanical interferences between detectors: vibrational coupling, esp. during installation, repairs, upgrades -- would like to understand better single IR hall layout + size, access/installation issues (eg. shafts, shielding walls) …

3. Philip Burrows MDI Panel Meeting 15/08/06 IR hall issues: underground assembly Current baseline hall for single IR costed by CFS: 72m (x) 32m (z) 35m (y) accommodates SiD comfortably SiD DoD specifies hall: 48m (x) 28m (z) 30m (y) assuming assembly underground (18m in z may be acceptable) If CCB approves single IR hall for 2 detectors would like to understand CFS model in new paradigm

4. Philip Burrows MDI Panel Meeting 15/08/06 SiD closed, on beamline, in 20m x 28m area 3.0 m Foot Mobile PAC1 Fixed PAC2 5.105 m Pit Wall Tunnel Shield Wall Door Barrel

5. Philip Burrows MDI Panel Meeting 15/08/06 SiD open, on beamline, in 20m x 28m area 3.00 m 2.775 m3.120 m 3.20 m 1.905 m 3.00 m 6.45 m 0.55 m

6. Philip Burrows MDI Panel Meeting 15/08/06 Underground assembly space 5.00 m 6.45 m 3.00 m 4.00 m 5.00 m Barrel Yoke rotated HCAL rotated Shield Wall (beam comm. only)

7. Philip Burrows MDI Panel Meeting 15/08/06 Elevation View Hall height: 30m ? –1.000 Barrel-floor –12.90 Detector diameter –12.90 Free space above detector –3.000 Crane bridge and hook NB need to know elevation of beamline rel. to floor (CFS assumes 8.6m, above assumes 7.5m)

8. Philip Burrows MDI Panel Meeting 15/08/06 Surface assembly model (1) No objection in principle to surface assembly Like to understand implications for cost savings, schedule, ‘CMS model’ … Given it some initial consideration (MIB 1/8/06) No detailed plan yet for assembly procedures -> size of surface hall or underground IR hall; happy to consider

9. Philip Burrows MDI Panel Meeting 15/08/06 Surface assembly model (2) Some initial considerations: surface crane capacity: barrel iron 2-3000T / n segments (8<n<16) coil package: c. 600T Hcal: c. 400T complete endcap door: c. 2000T / 6 pieces 1000T crane capacity may be OK shaft diameter: 9m may be OK 2-3 years of IR hall access needed for final assembly

10. Philip Burrows MDI Panel Meeting 15/08/06 Summary SiD supports BDS request for 14/14 mrad Xing with single IR hall at z=0: like to understand CFS IR hall model in this case SiD has no objection to concept of surface assembly: like to understand implications for cost savings, schedule, learn more about ‘CMS model’ Suggestion (for discussion) that respective hall + shaft costs be assigned to each detector concept rather than machine