I&T/Calibration Committee Meetings

STATUS OF OUR DOCUMENTS HERE

Eighth Meeting 13 June 2001, 10:00 PDT in the SATURN vrvs room.

Present: Eduardo do Couto e Silva, Hartmut Sadrozinski, Steve Ritz, Tune Kamae, Ed Shippey, Martin Nordby, Bob Hartman, Bernard Phlips, Gary Godfrey,  Michael Lovellette, Scott Williams, Tom Leisgang

AGENDA:

1) Announcements, agenda review, etc. (5')

2) Review of Functional Test Plan (15')  -- Lovellette

The current draft document addresses functional testing of the full LAT, but the verification testing during integration must be defined and elaborated.  In particular, the interfaces and operability of newly-integrated parts must be verified at each stage of the integration in a schedule-conscious manner.  ACTION:  Hartmut+Eduardo+Martin to draft the Integration Plan.  This will be posted on the documents page for comment within the next two weeks, with an accompanying email.

3) Status of GSE and Software Plan (15')  -- Williams

Scott promises a draft by 20 June.  Check the documents page, and please send him comments.

4) Full-LAT vibe tests? (10') -- Nordby

We reviewed the table of options (see agenda item 2 from meeting 6 below, page 5 of the document), and continued the discussion.  At issue are the many connections -- mechanical and electrical (bolts and connectors) -- in the LAT that will not be verified by subsystem testing.  These are acceptance-level tests for workmanship.  Thus, the question of the full-LAT vibe test is really a question of  how best to do the workmanship testing on these connections.  For example, would acoustic testing alone accomplish this task?

Martin and Ed are in contact with Scott Gordon, at GSFC, who is evaluating the coupled loads analysis, to get an assessment of these questions.  Answer expected within two weeks.

5) Status of Environmental Test Plan (20') -- Nordby

Due to saturation, Martin needs more time on this.  He is now working with ONE support to move this forward.

6) Status of Ground Calibration Plan (20') -- do Couto e Silva

The document is being revised by Eduardo to derive the tests more directly from the requirements.  Next draft by 25 June.  Eduardo reported that the discussions of whether there is a need for full-LAT beam testing have clarified the issues -- instead of listing the functional testing that a full-LAT beam test could accomplish, a list of the necessary functional testing will be generated and the options for how those tests can be performed will be explored.  

7) AOB

We did not schedule the next meeting.  There is plenty of work going on, and we will focus on the documents.  All current versions of the documents will be available at the link at the top of the page, and email notifications will be sent as major revisions are posted.

Seventh Meeting 1 June 2001, 8:30 PDT in the SATURN vrvs room.

Note that the room will be booked 30 minutes early for tuning/debugging the system.

Present: Tony, Martin, Scott Williams, Scott Sawyer, Eduardo, Hartmut, Bob Hartman, Steve, Tune

AGENDA:

1) Announcements, agenda review, etc. (5')

2) Review of status of the documents (30')

See document status page (link above).

• Environmental test plan -- little progress this week, but still on track for June 15 review.  At the next meeting, Martin will present his recommendation and justification on the issue of whether or not to do full-LAT vibe testing.
• Functional test plan -- we reviewed the draft (Michael could not attend).  There were many comments and suggestions for including missing items, which will be emailed to Michael and cc'd to everyone (ACTION).  ACTION: Hartmut is drafting the functional test plan for the tracker, including a discussion of strategies, and will circulate this next week.  This will be merged with the present document, and it may serve as a template for the other subsystems.
• The on-orbit calibration table was reviewed during the meeting.  It has also been sent to others (Dave Thompson, Dave Bertsch, Seth Digel, Peter) for review.  It appears this is sufficient for PDR, but additional comments are welcome.
• The GSE and support software document will be drafted by Scott Williams and Tom Leisgang next week, with a draft expected at the end of the week.  Check the documents status page for updates.
• The ground calibration draft document was presented by Eduardo.  He is on track for having the document done on time.  He is pulling together the earlier documents and discussions, and has reviewed the EGRET SLAC calibration plan as a model.  Issues to be resolved include low-energy photon calibrations and the hadron test matrix.  Eduardo reports a division of opinion on whether to recommend putting the whole LAT in a beam.  This is an important issue to resolve clearly, since it is likely to be the first question we'll be asked at PDR.  The beam test subgroup will produce a document outlining the issues, and will make a recommendation at the next meeting.   ACTION: Bob Hartman will try to find a copy of the EGRET Brookhaven calibration plan.

3) Report from the beam calibration subcommittee (10')

see above.

4) AOB

ACTION: Hartmut suggests we start placing documents that we have been using that are complete into Cyberdocs.

Sixth Meeting 22 May 2001, 13:00 PDT in the SATURN vrvs room. [note the new time]

Note that the room will be booked 30 minutes early for tuning/debugging the system.

AGENDA:

1) Announcements, agenda review, etc. (5')

2) Vibe testing plans - Martin (20')

3) Review of status of the documents (20'')

4) AOB

Fifth Meeting 11 May 2001, 8:30 AM PDT in SATURN vrvs room.  [note the new date]

Note that the room will be booked 30 minutes early for tuning/debugging the system.

We'll finish by 9:45 PDT to avoid conflicting with the BFEM pre-ship review.

PRESENT: Eduardo, Hartmut, Tune, Steve, Michael, Bernard, Ed, Martin, Scott.

AGENDA:

1) Announcements, agenda review, etc.(5')

2) Update on environmental test plan - Martin (5')

Awaiting LAT PS update; a big issue is the temperature range over which testing is done.

3) Update on beam test calibration plan - Eduardo/Tune/Hart-mut (10')

The beam test subgroup will meet next week (time TBA by Eduardo).  After evaluating the work, the group will set a date for release of the Ground Calibration Test Plan.

4) Functional test plan document status - Michael (5')

Comments received.  Draft to be released soon.

There was a good discussion about the need to include well-defined "stress testing" of the system, both during performance testing and functional testing, early and frequently throughout the I&T.

5) IOC GSE support document status - Scott (5')

Expect draft documents within 4 weeks.

6) To Vibe or Not to Vibe? - Martin/Ed (10')

Work on this has been delayed due to other pressing matters.  Ed is investigating the proposals by the spacecraft vendors to evaluate their proposed observatory-level environmental testing.  Martin and Ed will report back in two weeks.

7) Review of Action Items and finishing our work (20')

We will concentrate our efforts now on completing the listed documents.  The emphasis in each document will be on the items needed for PDR, but the documents will be complete in that they will capture the current state of the planning on all items.  Most documents should be ready for review within ~4 - 6 weeks.  Links to the current versions will be provided here.

8) AOB

Fourth Meeting 16 April 2001, 8:30 AM PDT in MARS vrvs room.

Note that the room is booked 30 minutes early for tuning/debugging the system.

AGENDA:

1) Announcements, agenda review, etc.(5')

2) Environmental test facilities, on-going issues -- Nordby (10')

3) Report from the Beam Test Subcommittee - do Couto e Silva et al (15')

4) Functional test planning status -- Lovellette (10')

5) Discussion of status of test and calibration plan -- all (5')

6) Status report on GSE requirements from functional test planning for LAT and subsystems -- Williams and Lovellette (20') [also see this presentation prepared by Scott]

7) Review of action items (10')

8) AOB

Minutes/Action Items

Present: do Couto e Silva, Hartman, Lovellette, Nordby, Phlips, Ritz, Sadrozinski, Shippey, Williams.  See agenda above for presentations.

1. ISSUE: we may need to lower the LAT temperature during functional testing to keep the TKR within operating temperature range.  There are already humidity control requirements, but they are especially important when we lower the LAT temperature.  A single tent for humidity control may be too risky.  This is also an issue for beam testing and cosmic ray testing.  ACTION: Martin will discuss this further with Bernard, and will include a proposal in his list of required facilities.
2. Martin is continuing to develop the list of required facilities for thermal testing.  We'll hear a status report in two weeks, and the document should be ready within four weeks.
3. Martin and Ed will present at the next meeting a summary of the issues related to whether or not to do a vibe test of the full LAT prior to integration with the spacecraft.
4. Michael raised the question of static load testing.  Martin will take this into account in the next version of his test plan.
5. Hartmut reported that a summary of the engineering model plans for the TKR (what is it, etc.) is available here (also linked to the beam test website).
6. Eduardo summarized the activities of the beam test planning group (see link in agenda item 3 above). There is a new member of the beam test subcommittee - Benoit Lott.   ACTION:  Eduardo will circulate the draft beam test calibration plan within a week.
7. Michael gave a status report on his Functional Test planning document.  ACTION: Micheal will circulate a draft next week (April 23).
8. Scott presented some slides describing the scope of the IOC GSE planning to support beam tests, subsystem integration, LAT integration, and LAT testing (including calibration).  There was a discussion of the definition of IOC and SAS responsibilities.  ACTION: Scott will provide a document describing the schedule, deliverables list, and manpower estimate for the next meeting.
9. We reviewed the open action items.
10. The next meeting will be on Friday 4 May at 8:30 PDT.

Third Meeting 30 March 2001, 8:30 AM PST in MARS vrvs room.

Note that the room is booked 30 minutes early for tuning/debugging the system.

AGENDA:

1) Announcements, etc. (5').

New draft document on the TKR tray testing from Nicola et al here .

2) Report from the Environmental Testing subgroup (see this document ).

1. Environmental testing-- Nordby and Nelson (10')

2. Functional testing-- Lovellette (10')

3. Cross-over testing-- Lauben (10')

4. Discussions, next steps (5')

3) Report from the Beam Test subgroup  (30')

1. Group activities are shown ot the subgroup web page here, and in a summary presentation here.
2. Current draft of LAT PS Science performance testing here. (will merge with this version).
   

4) Review of action items and schedule for deliverables (10')

Minutes/Action Items

Present: do Couto e Silva, Hartman, Lauben, Lovellette, Nelson, Nordby, Phlips, Ritz, Sadrozinski, Shippey, Waite, Williams.  See agenda above for presentations.

ACTION ITEMS:

1. The Environmental Testing subgroup has identified a number of vaguely stated requirements that need clarification.  Review the list of problematic requirements and initiate change process: Nordby, Thurston, Ritz within two weeks.
2. Read the draft environmental/functional test plan (see agenda item 2), comments to Nordby:  ALL within two weeks (sooner is better). Martin will implement and document the changes.
3. Review the 55% humidity spec with the CAL subysystem group: Phlips within two weeks.
4. Pull out list of facilities from draft environmental test plan, and produce a companion document with brief descriptions of each facility, when it is needed, and the duration of use: Nordby within two weeks.
5. Directly address the question of a full-LAT vibe test -- produce a list of issues and trace the relevant requirements: Nordby and Shippey within two weeks.
6. Develop the functional testing section of the draft environmental test plan (agend item 2) into a separate document.  Collect and review with each subsystem rep the functional testing needed for each subsystem.  For each of the three categories -- Aliveness, Limited Performance Test (LPT), Full Performance Test (FPT) -- list when the test would be done and the conditions needed for each test (e.g., thermal environment): Lovellette, with help from Eduardo in his spare time , within two weeks.  (Subsystem reps have already been contacted and have begun providing information to Michael).
7. Assess the implications for the GSE (hardware, software, running modes) of the functional testing.  Do this both for the full LAT and for the integration at the subsystem level (in consultation with each subsystem rep).  Williams and Lovellette, report back in two weeks on status.
8. Provide a writeup describing a large, external muon telescope that might be available at SLAC for full-LAT testing: Sadrozinski prior to the next meeting in two weeks.  DONE
9. Discuss with the ACD subsystem group the support for the calibration unit (how many tiles, configurability, etc., and how it can support the 4x1 and 2x2 configurations).  Also, are there any Engineering Model tiles and electronics planned?  Specifically, can these support bringing up the SLAC beamline and any interim high energy tests at CERN?  Also, carefully review the earlier 300 GeV backsplash measurements and recommend whether an additional test is needed.  Hartman to report at the next beam subgroup meeting in two weeks.
10. Remaining open items from the previous meeting (see below): Nordby, Ritz, Thurston, Sadrozinski, Nelson.
    

Next Meeting

The full committee will meet on Monday, 16 April at 8:30 PDT (11:30 EDT).  [When does Europe switch to daylight savings time??].  There will be a beam test subgroup meeting on Thursday, 12 April at 11:00 PDT (14:00 EDT).

Second Meeting 16 March 2001, 8:30 AM PST in NEW Mars vrvs room

AGENDA:

1) Announcements, VRVS debugging, etc. (5')

2) First pass tests for LAT PS verification (15') Ritz and Nordby

3) Subsystem testing prior to LAT I&T:

• TKR: Mazziotta and Sadrozinski (10')
• CAL: Phlips and Cordier (5')
• ACD: Thompson/Hartman (5')

[Elex/DAQ, FSW, and GSE planning will be done at a future meeting]

4) Status of LAT I&T Flow (10') Nordby_Lehman_Feb2001, Nordby_Nov2000

5) Discussion of facilities subgroups for beam testing and environmental testing (10')

6) Next meeting, AOB.

MINUTES/ACTION ITEMS

Present: do Couto e Silva, Haller, Hartman, Kamae, Lovellette, Nelson, Nordby, Phlips, Ritz, Sadrozinski, Shippey, Thompson, Williams.

See the links above for the presentations. The following issues and actions arose from the discussions.

We spun off two subgroups:

• Beam test subgroup to review and develop the relevant sections of the LAT PS science requirements verification (see link to Ritz in item 2 of the agenda above), and to draft the requirements for the beamline(s).  Also draft requirements for the ACD calibration unit (changing tower configurations may imply the need for a reconfigurable ACD). The group is do Couto e Silva (convenor), Kamae, Sadrozinski, Ritz, Hartman, and Phlips.  ACTION: group should meet ASAP and report back in two weeks. CLOSED.
• Environmental test subgroups to review and develop the relevant sections of the LAT PS environmental requirements verification (see link to Nordby in item 2 of the agenda above), and to draft the requirements for the environmental testing facilities.  The group is Nordby (convenor), Nelson, Shippey, Lovellette, Williams, and Lauben. ACTION: the group should meet ASAP and report back in two weeks. CLOSED.

ACTION: Update LAT PS to reflect  changes in the MSS, review operating mode requirements, review spec on livetime measurement precision. Ritz, Nordby, Thurston. Start change control process next week.  OPEN.

ACTION: Document the qualification plan for the SSDs. Nelson and Sadrozinski.  OPEN.

ACTION: LAT parts personnel (mechanical,  electrical) pro actively discuss parts issues with each subsystem manager. Thurston will coordinate this.  Started -- CLOSED.

ACTION: Post URL for Eric Grove's work on CAL calibration (see agenda item 3, CAL, above). Ritz (CLOSED -see references below).

ACTION: subsystem representatives on the committee (Phlips/Cordier, Hartman/Thompson, Sadrozinski/Mazziotta, Haller/Waite) review current I&T flow plan (see agenda item 4 above) and give feedback to Martin. Where possible, use this preliminary plan as a basis for starting planning for schedule, personnel, and facilities needs for the subsystems.  OPEN.

Some issues from the discussions:

• The testing for changes due to environmental stresses on science performance relative to the requirments must be developed further. Some work has been done on this issue regarding the pointing knowledge requirement (which must be added to the LAT PS to reflect the change in the MSS).
• How do we test for performance hysteresis at high rates (i.e., events occuring very close together in time) given that the SLAC beam has a low rep rate? Can we do this adequately with charge injection?
• During the discussions of the subsystem testing plans, some common issues arose that should be treated uniformly:
  • accelerated aging test plans
  • thermal (and other environmental) testing of the subsystem components

The subsystem representatives should discuss these within their respective subsystems.

• During the discussions of the LAT PS science verification and beam testing, a number of issues arose:
  • in addition to scans over theta and energy, we must be careful to cover the range of impact positions adequately, particulary if the beam profile is narrow, and to integrate over phi.
  • understanding the instrument performance for off-axis photons, particularly those that convert near the front of the TKR stack, may require more than 3 or 4 towers to be present in the calibration beam. This has implications for the schedule, and must be carefully evaluated.
  • evaluating the absolute effective area requires a significantly better understanding of the photon beam.

  The beam subgroup will address these issues.

First meeting 2 March 2001

Agenda , Minutes

REFERENCES

EGRET Ground Calibration paper ApJ S88, 629(1993) . Available here.

EGRET Flight Calibration paper ApJ S123, 203(1999) . Available here.

Eric Grove's talk on CAL calibration planning, click here and look at slides 19-26.

Environmental and functional test planning draft document available here.

Science performance test planning draft document will hopefully go here soon! (see this link for ongoing work)

New draft document on the TKR tray testing from Nicola et al here .

Hartmut's writeup on justification for a full-LAT muon telescope facility available here.

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