1. IFR End Door Enhancement Mechanical Engineering Status & Installation Issues H. James Krebs June 23, 2001

2. Earthquake Engineering Status Upgrade 1 –1” thick brass plates replace chambers in FWD end door gaps 8, 10, 12, 14, & 16 (28 tons) –Replace RPCs in 12 layers –Remove layer 18 and replace with double chambers in gaps 18 & 19 –Add steel absorber material added on forward end (28 tons) –Chamber belt added around end door periphery –Brass absorber added between flux bars (3.5 tons) –Remove upper counterweights (24 tons)

3. Earthquake Engineering Status Upgrade 2 –7/8” thick brass plates replace chambers in barrel gaps 7, 9, 11, 13 & 15 (59 tons) –Replace RPCs in 12 layers

4. Earthquake Engineering Status Investigation of floor slab strength continues –Floor is overstressed (nothing new) –End door feet must be redesigned End door track plates acceptable End door drives acceptable End door earthquake braces are sufficient

5. Earthquake Engineering Status Connections are satisfactory –End door to barrel (upper) –End door to barrel (lower) –X,Y & Z tie rods to barrel –X, Y & Z tie rods to floor Tie rods not studied yet – no big deal

6. Earthquake Engineering Status Earthquake isolator analysis –Original analysis assumes 0% coefficient of friction on end door sliders (overly conservative) –New analysis assumes.05 coefficient of friction on end door sliders (approved by PEP) –New detector displacements derived (8.23” max - 8.41” max previous) –We cheated (sort of) but PEP & Babar are happy Engineering is ready to begin EQ Committee approval process

7. Earthquake Engineering Status What if we added additional weight? –Engineering group feels adding an additional 5% to the detector weight may be achievable –Would need to redo all earthquake engineering thus far –On the edge in many areas – connections, braces, isolators –Already over the edge on the floor strength, end door feet –Adds to difficulty in achieving EQ committee approval

8. Brass Absorber Status Absorber detail design is complete –Drawings complete but not checked –Material specification complete but not checked –Engineering group desires to have collaboration approval to order the brass absorber by close of the collaboration meeting Work continues on absorber installation fixtures

9. Layer 18 & 19 Status Conceptual design is complete Not much change since Rome meeting

10. Platforms & Installation Fixtures Work is beginning on the installation work platforms No progress on chamber installation fixtures – still lower priority

11. Installation Schedule Absorber + RPCs + Layer 18 & 19 + Chamber Belt 3 months duration for mechanical installation –Two 8-hour shifts per day/ 5 days per week Does not include any time at end for commissioning Does not include any time for work by other systems