IB2  Endcap Muon Chamber Meeting
Below are the minutes for the Endcap Muon Chamber Meeting. If you find errors or wish to correct them, please contact me at apollina@fnal.gov.

Chamber Drawing Status
    P2 drawings were delivered by Vladislav. They do not include the frames drawing at this moment since je didn't receive them from Wisconsin.

By October 15, Vladislav will receive the PNPI chambers drawings.  Fermilab will build the next set of PNPI chambers (ME2/1) based on these drawings. It was not clear when the drawings for M3/1 would be received.  A chinese engineer will join Vladislav by September and start working on the drawings for the IHEP  chambers.

Panel Order
    Nelson reported on the visit to Plascore 2 weeks ago. It was clear from the visit that Plascore doesn't have the QA tooling necessary to insure the conformance of the panels to our specifications. Fermilab agreed that we will provide them the appropriate tooling. It was unclear if Plascore would do the measurements (for the increase in the panel cost that they already communicated to us) or if Fermilab will send people to Plascore to measure the panels (for a cost that appeared to be lower).  While we are working on the QA tooling, Plascore will concentrate on their assembly tooling to improve the quality of the panels. Mike Niemerski (the Plascore engineer that visited Fermilab last week) identified three possible points of improvement:

Core cutting: They will use a 5 feet wide table that should provide full support for the cutting of our wider core panels and decrease the problem of  "fatter edges".

Presses: They could investigate the effect of their presses on the presence of the "bumps" in the present panels (see report below by G.A.).

Curing Temperature: Plascore could  monitor the curing temperature for the panels and check its effect on the panel bowing.
 

Plascore also notified us that their process to produce the core for the panels will change by November (good thing it isn't changing in the middle of our production ! ) and that should imply a cost decrease of 25% in the core (it was not clear what this meant for the finished panels cost).
We decided to purchase 14 panels (2 chambers worth) for which we will require them to use the new wider table for the core cutting, to measure the core thickness and to give us their best effort on the presses.

Panels Measurements 
    Giorgio reported on some panels measurements done at Fermilab. All the panels measured (5 in total) show a large bow in the long side direction (12 feet). When the panels are placed under gravity of a flat granite table, the "long-side" bow largely disappears.  Although a full engineering analysis is not yet existing, it is hoped that this implies that in the final chamber assembly  this bow will disappear as well. In the short side direction there are 2 "ridges", running along the direction of the panel, where the panels bow by as much as 30-40 mils. These bows do not disappear under gravity. We do not know what happens in the final chamber. These "ridges" are located where the Plascore press feet are located, so they appear to be a manufacturing problem. Plascore knows about them, and they will check their production procedures to try to minimize the problem.
    Oleg presented his measurements on a dry run assembly of the P2 chamber. The  chamber was assembled in the horizontal position and he measured the sagitta between the chamber face and a straight edge laying on the chamber edges. He found a ~70 mils sagitta at the center and wide side of the chamber, which is clearly unacceptable. Approximately 20-30 mils are due to the buttons, which appear to be systematicaly smaller than the gap bars. This problem is easily solved. The remaining ~40 mils are unexplained for. Jay Hoffman (TD Materials Lab) presented some disturbing results on stress measurements he has being doing. He showed that applying a force of 15-20 lbs on a button produced a deflection (on a 2X2 inches piece) of 4-6 mils. This effect could explain the remaining sagging of the chambers.

 

MP9
    Most of the tooling has been moved to MP9 according to the plans put down during the previous meeting (the winding machine is still waiting for the final commissioning, but that is proceeding OK as of today, Sep. 4). The tooling is being reassembled in MP9 according to the plan discussed below.

 Plans for the P2 pre-production Chamber
   Giorgio presented detailed plans to get from here to the L3 milestone of assemblying the P2 pre-production chamber by November 16. All the participants received a list of the action items to focus on, in order to be able to make the chamber. Roughly speaking, we will spend the first half of September completing the tooling setup, assemble the chamber between September 15 and October 20, and start testing the chamber by the beginning of September. Yuri will present the plans for the cosmic test setup, in order to be ready to test the chamber as soon as it comes out of MP9.

 
 
 
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