Key Design Issues and Recent Reviews

1. US LHC ACCELERATOR PROJECT brookhaven - fermilab - berkeley Key Design Issues and Recent Reviews Tom Peterson, Fermilab DFBX PRR, October 23, 2002

2. DFBX (feed-box) -- design status • One of six design variants (BFBXC/G, points 2 and 8 left) is complete and released (271 drawings) • Engineering and top level drawings for the other five design variants are done. • Some detailed drawings remain (about 100 unique drawings) Tom Peterson -- US LHC Project

3. DFBX design meetings at LBL within the past year • December 11, 2001, review of results of November 2001 vendor fabrication study (PHPK and Meyer Tool, also Tom Peterson review of drawings) • February 25-26 (with Fermilab) • April 17-18 (with Fermilab, including Tom Nicol) • June 18-19 (with Fermilab and Don Brown) • August 6-8 (Don Brown reviewing drawings) • August 21-22 (with Fermilab, including Kerry Ewald) • September 4-5 (with Fermilab, Rob Van Weelderen and Vladislav Benda from CERN) • September 25-26 (with Fermilab) Tom Peterson -- US LHC Project

4. Vendor fabrication study • In October and November, 2001, PHPK and Meyer Tool reviewed the full (but at the time incomplete) set of drawings for DFBXC/G • Their charge was to “review the designs for manufacturability, including suggestions for design changes that would lead to cost reductions or more rapid fabrication.” • The issues outlined during the fabrication study set the design agenda for the past year. The recommendations have almost all been incorporated into the design. • In particular, a lot of attention has been given to tolerances, one of the main vendor recommendations Tom Peterson -- US LHC Project

5. Design issues and their resolution– tolerances and dimensioning • Tolerances were brought to the highest possible assembly level, such that they define the actual requirement Tom Peterson -- US LHC Project

6. Design issues and their resolution-- helium vessel design • Helium vessel access port weld detail with provisions for cutting • Helium vessel supports carry bus duct bellows pressure forces; bus duct gusseted for stiffness • Attachment of power lead chimney to top plate of vacuum vessel • Vessel meets ASME code except helium access door weld Tom Peterson -- US LHC Project

7. Design issues and their resolution-- helium vessel support design Static and dynamic load analyses for the vessel and support elements are complete Thin vertical invar rods carry vertical loads; helium vessel hangs from vacuum vessel top plate Horizontal invar rods carry axial loads and provide lateral stability Tom Peterson -- US LHC Project

8. Design issues and their resolution-- helium piping design Pipes hang from G-10 support plates in the vertical risers. Braided flex hose takes magnet interconnect motion as well as DFBX contraction; used extensively to prevent transmission of axial pressure loads at flex elements Bellows remain only in the main bus ducts and large pumping line. Pipes are free to slide in the other support plates. Tom Peterson -- US LHC Project

9. Special design features--lambda plate, buswork, current leads • Lambda plate R&D phase at LBL including prototype is a success. LBL will produce a pre-production unit with full length leads. Tom Peterson -- US LHC Project

10. Special design features--lambda plate, buswork, current leads • Completed specification for splicing superconducting leads and qualification contract with each vendor. Tom Peterson -- US LHC Project

11. Special design features--lambda plate, buswork, current leads • Pirelli is expected to deliver the first pair of HTS leads in November. Testing of the leads will be at Fermilab. Tom Peterson -- US LHC Project

12. Special design features--lambda plate, buswork, current leads • Completed specification and RFP for purchase of conventional vapor cooled leads. Tom Peterson -- US LHC Project

13. DFBX remaining design details • Some details for five remaining variants • Some new pipe routing arrangements • Variations of large pumping line supports • Variations of small pipe G-10 supports • Beam tube cooling details • These details are just “variations on a theme” Tom Peterson -- US LHC Project

14. DFBX remaining design details • Some interconnect weld details are not resolved with CERN but need not be resolved before contract is placed Tom Peterson -- US LHC Project

15. DFBX remaining design details • Some instrumentation details • Two instrument conduits are still under design. LBL will provide these subassemblies to the vendor. • Naming convention for magnet thermometers still not resolved with CERN • These are not problems for the RFP Tom Peterson -- US LHC Project

16. Design status for RFP • Engineering is complete for all boxes; remaining details are variations on the complete design and do not present any new engineering problems • One drawing package is complete • The vendors will have one complete design package with which to start making their estimates • The vendors have requested the one complete drawing package, rather than our holding the package until the other details are complete • The vendors will have all remaining details well before their final proposals are due Tom Peterson -- US LHC Project

17. Design Summary • The DFBX design has been very thoroughly engineered, documented and reviewed. • Issues raised by the various reviewers including the vendors have been addressed in the design and documentation. • Vendors will have the option to make modifications in order to follow their standard practices, reduce their cost, or speed up production, with LBL approval. • But the vendors have an excellent, detailed design as a baseline guide. • Fermilab will continue to work closely with LBL throughout the contract negotiations and fabrication. Tom Peterson -- US LHC Project