Minutes-4-4-2013

April 4, 2013 FDC meeting

Agenda

1. Production Construction Tracking (Dave)
   • Package #3 repair
2. Installation (Lubomir, Bill)
   • Cable installation: Rich's models [1], [2], [3]
   • Plans for practicing at Blue Crab
3. Engineering (Bill)
   • Cooling system status [4], [5], [6]
4. Electronics (Chris, Nick)
5. Tests at EEL126 FDC E-log (Beni)
6. Other

Minutes

Participants: Fernando, Eugene, Bill, Dave, Chris, Nick, Simon, Beni, and Lubomir.

Production

- Dave: will start wire deadening tomorrow; wire frames #2 and #3 will be the first to go with. In total 4 wire frames have to be deadened.

- Package #3 repair: we scanned all the wires of the HV sector #2 (on the wire frame of cell #6) using the camera of the motion station on the stringing table. There were three field wires with some stuff we could not clean. We disconnected these wires from the HV side, by un-soldering and cutting the end of the wire, but without success: the HV problem remained. Then we removed half of resistors at the HV side of the sense wires and the problem went away. Using this method we went down to 5 questionable wires, and at this moment Anatoly found a tip of a sense wire (~5mm) sticking out of the solder. After fixing this, the chamber now is holding HV already 10 hours. We will wait till tomorrow and then Casey will replace the three field wires, so the wire plane will be ready for installation by Monday. Bill suggested to glue/tape somehow the spacer ring to the wire frame when mounting it from the back of the package; will need more people for the cell isntallation.

Installation

- Yesterday, there was a "FDC cable installation" meeting on which Rich Getz presented his new plan shown on the three pictures attached above. Important change: the cables coming from the back of the installation cart don't have to run to the front of the magnet to reach the cable trays. This is possible because of the new openings in the floor next to the rails for the carts. These openings are just on the top of a new cable tray. To support the cables on the top, there will be a temporary movable frame. Beni suggested how to organize the cables on the top to make the insertion easier. Bill explained how the cables will be attached in between the packages and how the strain relief will be provided: using carbon tubes at the periphery.

- Everybody thinks this is a very good solution for the FDC cabling. Another important feature: the CDC cables will use a separate cable tray at the bottom below the platform. Thus, the installations of the FDC and CDC cables become independent.

- LV cabling: in the current scheme all the FDC LV cables (140) are connected to one rack. Fernando advocated to keep this scheme and bring the half of the LV cables from one side to the other somehow at the front of the magnet. Doing this directly on the mesh might be problematic due to the small distance to BCAL, but Bill will look at this. Attaching additional support ring at the front of the magnet for the CDC cables (Bill) may help.

- We discussed possible practicing at Blue Crab with the following configuration. We will use two installation carts, going downstream, one for one half of the mesh cylinder, and the other for one FDC package and the mock-up. The idea is to prototype one quadrant of the signal cables (132). The cables for that quadrant will come from the FDC package and the rest will be attached to the mock-up representing the other three packages. The cables will be attached up to the end of the mesh running between the rails. We have all the major parts to do this. The bearings on the mesh have to be installed. Will move also 132 signal cables from 117 to Blue Crab.

Engineering

-

Electronics

- Fernando: we have already 16 fADC125 and Cody is testing them. Some delays in this pre-production and the procurement is helping to accelerate it.

Tests at EEL126

- Beni at the beginning of the meeting showed results from the tests of the last production package (#2): entry 108 in the FDC E-log. All the channels without any exceptions are working fine. One of the HV connectors (from the side of the detector) had some issues, but was connected.

- The plan is to start preparing for the tests with the full electronics. For this tests, Beni's plan (not present at these discussions) is not to read all the samples, but to have the charge integration and timing extraction done in the ROCs. Eugene: what is the advantage of this compared to just writing all the samples to the disk and later do this off-line. Obviously, writing and reading the files will take much more time, but Beni may have better explanation. As for the cooling Bill says it must be ready in few weeks. A water chiller will be borrowed from FEL, instead of repairing the one they offered us before.

Other

- NO FDC meeting next week.

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