GLAST LAT Project March 24, 2003

6G Tracker Peer Review, WBS 4.1.4 1

GLAST Large Area Telescope:GLAST Large Area Telescope:

Tracker SubsystemWBS 4.1.4

6G: Tower module assembly

A. BrezI.N.F.N. Pisa

Brez@pi.infn.it

Gamma-ray Large Gamma-ray Large Area Space Area Space TelescopeTelescope

GLAST LAT Project March 24, 2003

6G Tracker Peer Review, WBS 4.1.4 2

Tower module assembly flow downTower module assembly flow down

• LAT tower module assembly follows this block diagram (see LAT-PS-01854 and LAT-PS-01855 and for details)

GLAST LAT Project March 24, 2003

6G Tracker Peer Review, WBS 4.1.4 3

Tray assembly system successfully tested during pre-engineering tower test.Fast (<1day) accurate and safe stacking of the trays.

Reference pins

Fixation holes

Safety pins

Cable opening

Fixture

Pre-engineering tower ready for transportation and tests

Lift system

LAT-PS-01854

GLAST LAT Project March 24, 2003

6G Tracker Peer Review, WBS 4.1.4 4

Cosmic ray test

Cosmic ray flux in Pisa INFN labs:∼10 Hz/tray surfaceIn one day∼500 events/stripDeep and complete tower understanding time 1 week∼

LAT-PS-01855

GLAST LAT Project March 24, 2003

6G Tracker Peer Review, WBS 4.1.4 5

ConclusionsConclusions

• With the help of a reference system made with precise aluminum walls, the stack of the trays is fast and safe.

• Complete functional test of the tower system before sidewalls fixation.• The sidewalls are then added. Each tray is referred to precision holes in the sidewalls

that allow a good alignment without the pileup of the tolerances.• The system has been tested. The tolerance was below the maximum allowable

(0.3mm). The process is fast (<1 day to mount a tower).• The tower is a good cosmic rays telescope. The cosmic rays flux allows a complete

and deep understanding at the single channel level in a short time (1 week)