MSU QC Manager: R. Miller
Updated:  June 24, 1999

Check List Cover Page
 

The cover page serves as an index to the optical instrumentation check list and to this document. It will be updated as necessary but will not need to be duplicated for each module. The latest version of this document is identified on the cover page by a reference link (REF), a revision number and date.

The check list serves as the log of all tasks that are performed during the optical instrumentation of each module of the TileCal. It should include a record of who did what, when it was done, how long it took to do, what batches of materials were used, the results of tests and checks, any problems that were encountered and what repairs were made. It will be our primary quality control tool, a means of communication within each instrumentation site and between sites, be a monitor of the progress being made and a source of information for solving and avoiding problems.

The optical instrumentation tasks are grouped under 11 headings, numbered 1 to 11. Under the column labeled 'DESCRIPTION' are links to the check lists for that set of tasks.  'QC Page' refers to the corresponding section in this document.

The 'CONTROL SYMBOLS' are used on the check sheets to indicate what action must be taken to satisfy the quality control for that task. All tasks will require at least a signature or initials:
S:  to indicate the persons who performed the task, and the time and date when it was finished. T
H: means that no subsequent tasks should be started on the module until the H task has been finished and passed inspection.
W: indicates a task that requires the signature of the designated Quality Control technician.
#: indicates that some data or other information is to be produced at that point.

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QC0:  Module Preparation

Start the 'Optics Instrumentation Check Sheet' for this module.  Check that the module serial number corresponds to the check sheet.

Check that the module is secure on the stands.  The stands should be symmetrically placed under the base so that the module does not rock.

 Inspect the module and record on the check sheets the location of any of the following problems:
 

• Glue remaining in slots
• Spacer rings displaced into slots
• Burrs on weld bars at edge of girder
• Abnormal spacing between submodules
• Paint runs or flakes in slots or girder
• Warped or undersize slots (check any suspicious slots with a gauge plate)
• Oil or other contaminents on surfaces
Correct any problems.

Sign and date the check sheet.

Report any serious or recurrent problems to the Quality Control technician.


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QC1:  Tile Inspection
 

Before inserting the tiles, they should be inspected (in a stack of about 20 tiles):

• Check that the tiles have a blue color similar to the standard tile when back lit with flourescent light or normal lamp.
• Tile end surfaces should be clean and undamaged.
• Tile wrappers should be recessed approximately 2 mm from the tile end surfaces
Record the batch numbers of the tiles on the check sheet.

After tiles have been inserted into the module, check that:

• All tiles are the correct size and centered in slots (end surfaces should all be visible and about 4 mm below the edge of the master plates).
• Tile end surfaces should be clean and undamaged.
• Tile wrappers should not extend beyond the tile end surfaces.
Repair or replace any problem tiles.

Sign and date the check sheet.

Report any serious or recurrent problems.
 

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QC2:  Verify fiber lengths and sorting

Record the batch numbers of the profiles/fibers.

Record the ID numbers of the ITC fiber assemblies (for the EB's only) and the laser fiber bundles.

Check all WLS fibers:

• Check that the fibres that belong to the same cell have the same length.
• Count the number of fibers in sequence with the same length, compare with the model.

Repair or replace any problem fibers or profiles.

Sign and date the check sheet.

Report any serious or recurrent problems.

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QC3:  Verify routing with a light source (method may be site dependent)
 

(Task Definition under Development)
QC3 (MSU ):

Check all fiber sub-bundles on both sides of the module:

• Position the light source at the first tile of a cell - check that a fiber in the correct bundle is lit.
• Move the light source one tile at a time - check that a fiber is lit at each step.
• Note the source position when no fiber is lit - it should correspond to the beginning of the next cell.
Repair any problems.

Sign and date the check sheet.

Report any serious or recurrent problems.
 

QC3 (CERN) :

Check all fiber sub-bundles on both sides of the module:

• Insert the two 3m light tubes into the two ends of the module.
• Turn on the light tube: the blue LED's will illuminate alternate cells.
• Check that all of the fibers that belong to the illuminated cells are lit and that none from the alternate cells are lit.

Repair any problems.

Sign and date the check sheet.

Report any serious or recurrent problems.

QC3 (BCN):

Check all fiber sub-bundles on both sides of the module:

• Insert the 1.5 m light tubes into the module.
•  Turn on the light tube: the lamps will illuminate cells alternatively.
•  Check that all of the fibers that belong to the illuminated cells are lit and that none from the alternate cells are lit.


Repair any problems.

Sign and date the check sheet.

Report any serious or recurrent problems
 
 

QC4:  Check for damaged fibers

Inspect the WLS fibers from the point where they exit the profile to the point where they enter the aspirin tube. Look for any of the following problems:
• Broken fibers.
• Stress crazing of the cladding.
• Knick or scratches in the cladding.
• Fibers with sharp bends (radii less than 50 mm).
• Fibers in direct contact with the weld bars or corners of the girder.

Repair or replace fibers with any of these problems.

Sign and date the check sheet.

Report any serious or recurrent problems.

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QC5:  Inspect the fiber ends

Inspect the polished fiber ends with the video system -the epoxy surfaces should be completely cured, mirror smooth, without scratches or chips.

Record any problem on the check sheet and notify the QC manager.

Sign and date the check sheet.

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QC6: Quantitative test and Certification

                         (Task Definition under Development)

The module is scanned by inserting a cesium source (for the Barrel) in the source tubes or a LED (for the EB's) in the Tile/Fe plates and recording the signal from the PMT's as the source/LED is positioned at each tile.

The source/PMT/DAQ system should be calibrated to give a signal, s, in normalized units
(pe/GeV ?)

The source/PMT/DAQ system should have sufficient accuracy and precision to measure the
signal variation expected from tiles and fibers (systematic plus statistical errors < 10 % ? ).

The analysis should include:

  1.The average and rms over all tiles of S, the signal sum of both PMTs: <S>, rms(S)
  2.The average and rms over all tiles of D, the signal differences between PMTs: <D>,
     rms(D)
  3.The average and rms of S and D over the tiles within each readout cell I: <S>I, rms(S) I ,
     <D> I, rms(D)I
  4.The list of tiles in each cell for which (S ? ) deviates > (3 ?) x "expected rms for that cell"
     from the "expected average for that cell".

A cell is certified to be "Good" if no more than (3% ? ) of the tiles in that cell fail the test (4
above). A cell is certified to be "Acceptable" if no more than (10% ? ) of the tiles in that cell fail
the test.

A module is certified to be "Good" if (all ? ) cells are good. A module is certified to be
"Acceptable" if (all ? ) cells are acceptable.

Modules that are not acceptable will be repaired.

Test data and analysis results will be maintained in a standard format in a data base available to
everyone in the ATLAS collaboration.

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QC7: Test the source tubes

                         (Task Definition under Development)