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January 5, 2012 FDC meeting


  1. Production Construction Tracking (Dave)
    • Production update
    • Second package tests (Lubomir)
  2. Engineering update (Bill)
    • Cooling system
  3. Electronics update (Chris)
    • Pre-amp cards
    • HV cabling
    • Grounding (Lubomir)
    • LV cabling Vlad's scheme
  4. Testing in 126 (Beni)
  5. TDR (Simon)
  6. Other


Participants: Bill, Dave, Chris, Mark, Simon, Beni (ESNET), Eugene, and Lubomir.


- Dave for the last cell of the second package: a field wire was replaced on the wire plane yesterday to be cleaned today, daughter cards were glued on the type-2 cathode today, type-1 cathode is ready. Tomorrow we will have all the parts of the last cell ready for testing and installation. Next cell (for third package): wire frame was laminated, type-1 cathode ready, working on the flaps for the type-2 cathode. For the nex wire frame lamination we will use a board with the vias not sealed (we have several of this kind); Bill suggested using Hysol to cover the vias right after lamination.

- The fifth cell of the second package was installed right before the break and was tested this week successfully. It took long time (~10 days) to condition the chamber: Epon didn't dry as usual or gas flow was too low during the break?


- Bill showed pictures for different parts of the cooling system: pump, manifold. The pump is supposed to operate at ~100psi. The coolant (Fluorinert) is heavier (1.73g/cm^3) than watter.

- Cu tubing: by directly measuring the weight of a tube piece we found the tube is heavier than what was used in the simulations. Later it turned out that the tubing was simulated correctly, according to the specifications for the tube sizes: 4mm OD and 2.79mm ID. For 4mm OD and Cu density of 8.96 g/cm^3 from the weight measurements one gets 2.14mm ID. After the meeting direct ID measurements confirmed the specified 2.79mm. The only explanation so far is that the density of the tube material is higher.

- We discussed if we need additional hubs and pins to assemble the last two packages, or we can re-use some of those from the already assembled packages. We need the hubs for the tests in 126 (to attach the strongback).


- Chris: made 4 more pre-amp sets (22 each) for the remaining cells in the first package. Will do one more set to be installed on the second package for testing purposes. All the pre-amps will be tested by Cody and likely will have them next week.

- Chris will make the HV connections on the first package next week; before that we have to do the labeling.

- Vlad came with a scheme for the cathode LV cables: three types with distances between the four connectors of 8-3-8, 6-3-3, and 3-3-3 inches. In addition will have anode LV cables with two connectors 2.75" apart. We discussed how to label the connectors/cables to help their installation. Certainly color coding will be used for the different cable types, but we need also labels (difficult to be put on these connectors).

- Grounding: it turned out that measuring the resistance with probes directly on the pre-amp clamps (coated aluminum) gives strange results, but when we measured it between the Cu tubes and the pre-amp card it turned out to be practically zero. In this case the grounding with the Cu tube is an option that has to be tested in 126 and compared to the scheme when using separate ground clamps and wires/braided ground straps.

Testing at 126

- Beni asked if the flat cables for the translation cards are ready. Chris will work on them after he's done with the other stuff.

- Strip grounding: since we will have all the pre-amp installed we discussed different options. Will just applying LV put the strips to ground potential? If yes, we need LV cables. Beni proposed using Al or Cu tape at the pre-amp connector, or (Chris) just put female connector on the pre-amp with the pins at the other side taped; then we need 108 connectors. Has to be discussed with Fernando.


- Simon worked before the holidays on the introduction. He included also GARFIELD simulations for different gas mixtures and with/without magnetic field that will be moved to the "Gas consideration" section. Lubomir will continue working on the package subsystems and asked Bill and Dave for some additional pictures.