Minutes of the August 5 Tracker Meeting
1) Latest tray status and test results
Andrea had sent some results on the Tower-A bottom tray static test. Chris expressed concern about the torque loss in the static test. He emphasized to be sure to torque stripe the nuts in Tower A before the vibration test.
Andrea said that the torque loss did not exceed the limits defined in the procedure. The results were essentially equivalent to those of the EM tower. He will study the data more and make a more careful comparison. At the end of the test there was a problem with removing one stud on a corner flexure (+y-x) which was stuck to the cones. It was a non-coated stud. Arthur said that at the end of the month he will provide new static test hardware.
Luca Baldini is at G&A testing more trays that are wire bonded, but no results were yet available.
Riccardo reported that only the top tray remains to be vibe tested and that will be done tomorrow). All vibration tests were successful. The Kapton-reworked trays passed the T/V test in Rome and are now at G&A. All remaining tray panels are going to Pisa tonight and to Rome tomorrow. The top tray will fly to Rome tomorrow, and all the T/V tests will be completed before the end of the weekend. Monday G&A will have all the trays.
2) Tower (and tray) survival test temperature requirement
Robert reported that working the request to lower the test temperature is very difficult this week because the thermal engineers are all on vacation. He had talked to Dick Horn about the issue, and Dick agreed that a 5 degree reduction (from 50C to 45C) could be contemplated and probably could eventually be agreed upon. Nevertheless there was no way to finalize such a change in time for the weekend testing. Anyway, Sandro said that the Tower-A tests will go forward at 55 degrees.
3) Transportation requirements for trays
Robert said he had talked to Martin about this. Martin will have John Ku do some analysis. He needed, however, the drawings of the tray box and the handles that support the tray (Emilio sent those and they were forwarded to Martin).
4) SLAC deliveries for Tower A
Sandro and Emilio requested that SLAC postpone the shipping by about 1 week, because they will not be able to retrieve items from the airport until August 23.
- Lifting fixture: ready to ship
- TEM/PS for T/V testing: there was a problem with the cable bias, but it turned out that the cable jumper was bad. Hiro will continue working this issue to get the EGSE ready to ship to Italy.
- Inner container and cable holding plate: proof testing will start tomorrow and require a couple of days. We need to add holes to the top for attachment of the data logger. Chris expressed concerned about the weight of the logger and suggested it would be better for it to be closer to the tower/Grid interface. Chris wants a copy of the container drawings.
- Outer container and data logger: the logger is ordered; a PR is out for the container and the spec is out for review. There was some concern about the strength of the fasteners between the container and pallet. Will they be strong enough if only the pallet is strapped to the truck or airplane? Nanda thought we need attach points on the container, particularly for the airplane.
o M2.5, 100 degree: Jeff said these were sent already
o M4 6mm: under inspection at SLAC
- I/F hardware: Arthur will hand carry all this stuff to Pisa
o M5 nuts: in hand
o Inner and outer cones: in hand
o Studs: enough are in hand for Tower A, but Arthur prefers to use studs from a new order shortly to arrive. They have a looser thread class and should be easier to work with.
o Hex bushings: getting coated
o Shims: still need to be plated
- Alignment tools: Peter said that Pisa should have all of them needed for Tower A. He has a chart to email to Pisa. He will in any case send some replacement and backup tools, probably by hand carry
- Digital torque meter: ready to ship
- Cable bending tool and cable installation mockup, with cable test samples: Arthur said that the tools should be at SLAC by now. The mockup can be made in a couple days; its drawings are almost ready.
- 1.5in tooling balls: Arthur will have 10 in the next day or so
- Reflector ball nests and magnets: nests are in metrology; magnets are on order---Jeff needs to expedite them
- Solithane: ready to ship; Jeff needs to get it re-cert’ed however
- Locktite 401: ready to ship
- Tower baseplate assembly: Jeff will check with purchasing and Humboldt. There was a small amount of machining still to be done, but the vendor needs SLAC approval for supplemental funding; Arthur said he also wants some extra square nuts
- cable brackets and clips: these are not done machining yet. There will be a spare bracket for tower A plus spare clips. Robert recommended using the spare bracket to test the assembly procedure on the EM tower. Robert talk to Martin about grounding of the brackets.
5) Other deliveries
- MCMs: a set of 31 is ready to ship, as soon as QA give the go-ahead.
- Bias circuits: 144 bias circuit ready to ship. Robert will talk to Jerry about future delivery rates from Parlex. Plyform is anxious to have assurance of adequate supplies when mass production of trays begins in September.
- Bottom tray honeycomb: they have been sitting at SLAC for at least a month. This week QA is checking them over, and then they will be ready to ship to Pisa.
6) Tower assembly preparations
- Schedule: INFN is still on schedule for an August 25 PRR and August 26 start of tower assembly. In fact, the trays are going to G&A 1 day in advance of the plan.
- Procedure: draft #3 is out for review and comments.
- Test procedure draft: Luca Baldini will sent the latest draft to Hiro.
- Assembly drawings are out for review: they look good to Emilio. He said that he has some suggestions for additional dimension lines and another view to send to Martin.
- Alignment plan/procedure status: a new plan draft was circulated at SLAC last week. The latest plan needs to go to Italy to be sure that their procedures are in agreement.
- Travel: Robert and Arthur arrive August 24 in the evening.
- At the Tracker meeting August 19 we will review the status of hardware and documentation. An internal Tracker preliminary production readiness review will take place by telecon on August 23. The final PRR will be August 25.