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]
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 CDC cables (Bill) may help, as well.

- 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. They will be attached up to the end of the mesh running between the rails. We have all the parts to do this, except the bearings on the mesh have to be installed. Will move also 132 signal cables from 117 to Blue Crab.