GLAST LAT Project
Gamma-ray Large
Area Space
Telescope
1 November 2004
GLAST Large Area Telescope:
Test Planning Selected Topics
Pat Hascall
SLAC
System Engineering Manager
phascall@slac.stanford.edu
x4266
LAT System Engineering
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GLAST LAT Project
1 November 2004
Agenda
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Changes to Tracker tests
Receiving test optimization
Grid integration test optimization
Status/plans for Performance and Ops Test Plan
LAT System Engineering
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GLAST LAT Project
1 November 2004
Changes to Tracker Tests
New
Old
Section section
Changes
General
Added sentence to define the purpose for the test
TE101
TE101
Added testing of each flex cable independently
Added variation of bias voltage from 0 to 120V
TE303
None
Added test of GTFE noise occupancy. This uses cosmics, where
TE601 uses charge injection
TE304
TE303
Title change, some change to test description
TE305
None
Added test, same as TE304 except layers are enabled rather than
GTFEs
TE306
TE304
Title change
TE307
None
Added test, similar to TE305, except uses 2 threshold values
rather than a threshold scan
TE403
TE502
Added phrase that the test can be merged with SVAC collection
TE603
TE603
Removed analysis method text
TE501
Test deleted – Layer noise occupancy – replaced by TE303
LAT System Engineering
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GLAST LAT Project
1 November 2004
Current Tracker Flow
• Received at SLAC
• EGSE TEM/TPS installed and Piza tests repeated as a post ship
test
– Non GASU test stand
– Procedures used TBD
• Turned over to I&T (potentially with EGSE TEM/TPS removed)
and receiving tests performed
– Non GASU test stand
– I&T procedures used
• EGSE TEM/TPS removed, integrated with CAL and flight
TEM/TPS
LAT System Engineering
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GLAST LAT Project
1 November 2004
Tracker Flow Discussion
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•
Propose combining post ship test and receiving test
– Both tests use the same scripts (with a few exceptions, discussed
below)
– Both tests use the same version of EGSE
– If the tests are not combined, then there should be a single mate
to an EGSE TEM/TPS and test crate so the post ship test and
receiving test share a test configuration
Special cases/issues
– TE101 uses a breakout box on the flex cables
• Only run once for the post ship test
• Tracker team will run using Tracker procedures (need to verify
the procedures exist in a form that can be run at SLAC)
– Tests TE601 to TE704 are not run at Pizza, but are used to
characterize the tracker and potentially sell off some requirements
• Under the combined test approach, these tests would be first
run under I&T control after the tracker tower is “received”
LAT System Engineering
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GLAST LAT Project
1 November 2004
Grid Integration Test Optimization
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•
Current plan (for third and higher towers)
– Mechanically integrate tower n into the grid
• Connect GASU based external test crate and run LPT
– Mechanically integrate tower n+1 into the grid
• Connect GASU based external test crate and run LPT
– Mate flight cables to towers n and n+1
– Perform LPT on towers n and n+1 using EM GASU
– If needed, remate cables to other towers
– CPT/LPT and SVAC tests on towers 1 to n+1
The LPT on towers n and n+1 do not add significant value and should
be deleted
– They break up the cabling process (in some cases) into two
phases
– The benefit is an earlier indication of a problem in mating the flight
cables to the GASU or PDU (low probability)
– Eliminating this test will not significantly hamper troubleshooting
if a problem does occur
LAT System Engineering
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GLAST LAT Project
1 November 2004
Performance and Operations Test Plan Plan
• Goal is to start the release process within the next few weeks
– Tracker test changes incorporated into document
– Calorimeter test changes (configuration changes, order of
tests) expected to be defined within a week
– Trigger test definitions
• Meeting with Su Dong this afternoon to determine what
test definitions are currently available, and will
incorporate those
– SVAC test definitions
• Eduardo is defining
• Will incorporate either high level descriptions or pointer
to Eduardo’s document
– End-to-End test definitions
• Will baseline existing set, may be changes based on
feedback from the yet to be determined review
committee
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