1. Where to put Towers A and B in the Grid – technical issues 18-Jan-2005 L. Wai (SLAC/Group K) for LAT I&T

2. Baseline plan for first two towers Defined in LAT-MD-676 TEM/TPS – GASU/PDU cable lengths optimized for baseline sequence First two towers in baseline sequence are bays 8 & 9 Connector savers on first TEM/TPS come off to allow insertion of second CAL module Flight TEM/TPS – GASU/PDU cables and associated cable tray hardware are installed for 2-tower testing 12131415 891011 4567 0123 +X +Y PDU GASU MGSE rotation axis +Z coming out of page SIU radiator

3. Baseline plan reasoning Start on PDU side and work towards SIU side for ease of cable installation Start in center and work towards edges for ease of tower installation Install “opposing” pairs including associated cable trays and flight cables to minimize risk in electrical testing

4. New considerations since baseline planning RisksMitigations TKR-A has a number of NCRs, many more than TKR-B, and hopefully TKR-1 will even be better. Put TKR-A in one of bays 0, 3, 12, 15 (corner location) TEM/TPS – GASU/PDU flight cables, cable trays may not be ready in time for 2 - tower testing Don’t remove connector savers and use EGSE cables; i.e. don’t install “opposing” pair. LATTE test software may not be ready to support > tower 0 configurations in time for first tower. Need LATTE 4.7.0 release. Install TKR A in grid bay 0. We expect software/hardware support for all grid bays to be ready by the time TKR-B arrives. However, still need neighboring pair for two-tower test (SVAC data analysis requirement) so TKR-B installed in grid bay 4.

5. Particle physics detector “intuition” Put the best detectors on the inside; for LAT, this means bays 5, 6, 9, 10, Put detectors on the outside good enough for background rejection; for LAT, put towers with most bad channels in corners Don’t use data from outside an analysis defined “fiducial volume” in final analysis

6. Best option, given current information and status of flight hardware and EGSE: Grid bays 0,4 12131415 891011 4567 0123

7. Proposed installation sequence TKR-A / FM104 into bay 0 TKR-B / FM105 into bay 4 Keep connector savers on and use EGSE TEM/TPS-GASU/PDU cables for 2-tower test Return to start of baseline installation sequence with subsequent towers

8. Cross-checks Martin Nordby (integration issues) – “no show stoppers” Gary Godfrey (Van De Graaff issues) –“no show stoppers” Eric Gawehn (MGSE issues) –“no show stoppers” Bill Atwood (physics issues) –“no show stoppers”