Difference between revisions of "Minutes-11-7-2013"

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(Created page with "November 7, 2013 FDC meeting = Agenda = # Installation status[http://www.jlab.org/Hall-D/detector/fdc/installation/FDC_installation.pdf] # Engineering (Bill) #* FDC survey #* Co...")
 
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# Installation status[http://www.jlab.org/Hall-D/detector/fdc/installation/FDC_installation.pdf]
 
# Installation status[http://www.jlab.org/Hall-D/detector/fdc/installation/FDC_installation.pdf]
 
# Engineering (Bill)
 
# Engineering (Bill)
−
#* FDC survey
+
#* FDC survey [http://www.jlab.org/Hall-D/detector/fdc/installation/Individual_PlanesFlatnessPointsXYZ.txt.xlsx full flatness results], [http://www.jlab.org/Hall-D/detector/fdc/installation/drift_cell_spacing_values.xlsx package thickness in the model]
 
#* Cooling system
 
#* Cooling system
 
# Electronics (Chris, Nick)  
 
# Electronics (Chris, Nick)  
 
# Other
 
# Other
−
 
−
<!--
 
  
 
= Minutes =
 
= Minutes =
  
−
Participants: Fernando, Bill, Eugene, Glenn, Tom, Tim, Chris, Simon, Nick, Vlad, Beni, and Lubomir. Long meeting discussing the survey/alignments most of the time.  
+
Participants: Eugene, Fernando, Dave, Nick, Simon, Vlad, Beni, Bill(came later), and Lubomir.
  
 
== Installation ==
 
== Installation ==
  
−
- The results from the survey of the FDC on the floor in the Hall are attached (still preliminary). The main conclusions: flatness of all the packages is OK (max deviation from the best fitted plane is 0.022"=0.56 mm). The centering of all the packages is perfect. The main concern is that the tilt (pitch and yaw) of the packages changed if compared to the Blue Crab measurements, which means FDC is flexible to this extend. Mostly the first and the last packages had deviations up to 0.66 mm. We just need to know the tilts, but the question is what will happen when FDC is moved inside the magnet. Eugene's point: it's very difficult to do tilt corrections using the beam data, we need to know the z positions better than 0.5mm and most importantly be sure it doesn't change when inserting the FDC. Independently, Bill and Lubomir measured the distance between the rails on the FDC and mesh carts and at the upstream end of BCAL. The rails in BCAL and the mesh cart matched very well, but the distance b/n rails on the FDC cart was by 0.8 mm different at the two ends. Tim and Tom say this doesn't cause additional friction and therefore deformation (i.e. it doesn't explain the above discrepancy b/n Blue Crab and Hall survey).  
+
- FDC has been moved on the platform and inserted in the magnet last Friday. Inside the magnet a survey of the downstream and upstream side has been done. Also FDC has been moved inside the magnet, and re-surveyed. Repeatability was very good (except for z-direction translation). Once the reflectors are installed the FDC will be moved again to the floor to survey the reflectors w.r.t. the already surveyed points. The work on the mesh has not started yet.
 +
 +
- Bill received one reflector (made out of fused silica) and glued it to the holder. It has been tested then by the survey group: they found that it can be used at up to 6 m distance from the Fero unit with a resolution of 0.1 mm. The resolution was estimated from the repeatability of the measurements, keeping the positions the same. The new 16 reflectors (regular glass) have arrived and Bill will glue them to the holders. He will give one to the survey group for tests again, since the material is different. At the beginning of next week he will glue the holders to the gusset rings of the packages; there's a jig to fix their positions.  
  
−
- Therefore Tim, Bill, Tom proposed (and everybody agreed) to try to do survey when the FDC is in its final position connected with cables. Most of the discussions: if it is possible, and how to do it. For the outer packages everybody agrees it is doable. For the inner packages there must be different solutions, but for now Bill will start looking for non-magnetic targets to be installed in points visible from the sides when the FDC is inside the magnet.
+
- The chilled water system must be ready now. According to Bill it will take just several hours to connect the chiller to the FDC and the chilled water, then we can test the FDC for leakage.
−
 
+
−
- The short term plan: since we think the survey of the FDC in final position is doable we can go ahead and put FDC back on the platform (on Friday). Then we will move it in and out of the magnet and do the survey in both positions. Tom will have people working on the cable mesh. After it's done we can start cabling.
+
−
 
+
−
- FDC was moved to the Hall a week ago (Oct 24) (see pictures attached). Since then it is continuously flashed with gas and it bubbles normally. We tried to insert FDC in the magnet and it was almost flash with the upstream end of BCAL but got stuck there. The problem was a HV connector caught the head of a screw on the rails (last picture). The size of the heads turned out to be bigger for the rails inside the BCAL. These screws will be replaced (one by one); at the same time the the plates holding the HV connector were modified the move the connector close to the beam. Since Monday the FDC is down on the floor for the survey. It was not possible to do it on the platform. There Casey also connected the cooling manifolds with tubes.
+
  
 
== Engineering ==
 
== Engineering ==
  
−
- Apart from the above discussions Eugene asked about the status with the chilled water and the cooling system. Bill: the piping is done and they are now testing it. Eugene: what is the water pressure (100psi) and what will happen if the piping breaks (very bad).
+
- Thickness of the packages: the thickness of a cell used so far in the simulation and data analyses was 2.1254 cm. By comparing the angles reconstructed from the Indiana chambers to those from the FDC, Lubomir estimated the thickness should be 2.15 +/- 0.1 cm (for the third package). This created some confusion that the nominal value may differ from the measured one due to the thickness of the glue on the cathodes that is not well controllable. However the problem was solved when Bill looked at the recent I-deas model and found the value there's 2.145 cm (after the meeting, xml file attached). He calculated also from the model the thickness of the full package: 14.42 cm and compared it to the results of the gusset flatness survey (attached) which gives 14.43 cmm for the first package: very good agreement! Bill is going to look at the other packages too.
  
 
== Electronics ==
 
== Electronics ==
  
−
- Nick made a presentation (linked above) about where the cables are on the platform and how the boxes are labeled. So far the signal cables for the first package and the LV cables are sorted in this way. We will first connect one quadrant of package #1, then same quadrant for package #2 ... starting with the LV cables. Therefore we will need the signal cables for all the packages almost from the beginning, but this will be done soon (Nick).
+
- The LV system will be installed at the north side; right now only the patch panels are there but Nick will install the power supplies as well. The HV system is already installed. After some discussions, the best will be to first install all the LV cables, route all of them to the top north cable tray and connect them permanently to the panels there. The cables that come from the south side should be lifted above the mesh and then directed to the north: we need open views to the reflectors.  
−
 
+
−
- About 10 cables from each package are missing, Tom will check if those are in the ESB used there for the mock-up.  
+
−
 
+
−
== Tests at EEL126 ==
+
  
−
- Beni was able to use the pulser on the new F1TDC: the width of the timing distributions with the pulser is ~0.3 ns.
+
- At the beginning one VXS crate will be installed (even temporary) at the north side to be used in the mini-DAQ to test the cable connections during the first phase of the cabling. It will have at least one F1TDC and one fADC125. For the crate and the LV power supplies we may need 208V and therefore we will move the transformer there. We expect the racks to be powered in several weeks from now.  
  
−
-->
+
- Nick now has all the LV and signal cables, except for the spare signal cables for package 1.

Latest revision as of 19:20, 7 November 2013

November 7, 2013 FDC meeting

Agenda

  1. Installation status[1]
  2. Engineering (Bill)
  3. Electronics (Chris, Nick)
  4. Other

Minutes

Participants: Eugene, Fernando, Dave, Nick, Simon, Vlad, Beni, Bill(came later), and Lubomir.

Installation

- FDC has been moved on the platform and inserted in the magnet last Friday. Inside the magnet a survey of the downstream and upstream side has been done. Also FDC has been moved inside the magnet, and re-surveyed. Repeatability was very good (except for z-direction translation). Once the reflectors are installed the FDC will be moved again to the floor to survey the reflectors w.r.t. the already surveyed points. The work on the mesh has not started yet.

- Bill received one reflector (made out of fused silica) and glued it to the holder. It has been tested then by the survey group: they found that it can be used at up to 6 m distance from the Fero unit with a resolution of 0.1 mm. The resolution was estimated from the repeatability of the measurements, keeping the positions the same. The new 16 reflectors (regular glass) have arrived and Bill will glue them to the holders. He will give one to the survey group for tests again, since the material is different. At the beginning of next week he will glue the holders to the gusset rings of the packages; there's a jig to fix their positions.

- The chilled water system must be ready now. According to Bill it will take just several hours to connect the chiller to the FDC and the chilled water, then we can test the FDC for leakage.

Engineering

- Thickness of the packages: the thickness of a cell used so far in the simulation and data analyses was 2.1254 cm. By comparing the angles reconstructed from the Indiana chambers to those from the FDC, Lubomir estimated the thickness should be 2.15 +/- 0.1 cm (for the third package). This created some confusion that the nominal value may differ from the measured one due to the thickness of the glue on the cathodes that is not well controllable. However the problem was solved when Bill looked at the recent I-deas model and found the value there's 2.145 cm (after the meeting, xml file attached). He calculated also from the model the thickness of the full package: 14.42 cm and compared it to the results of the gusset flatness survey (attached) which gives 14.43 cmm for the first package: very good agreement! Bill is going to look at the other packages too.

Electronics

- The LV system will be installed at the north side; right now only the patch panels are there but Nick will install the power supplies as well. The HV system is already installed. After some discussions, the best will be to first install all the LV cables, route all of them to the top north cable tray and connect them permanently to the panels there. The cables that come from the south side should be lifted above the mesh and then directed to the north: we need open views to the reflectors.

- At the beginning one VXS crate will be installed (even temporary) at the north side to be used in the mini-DAQ to test the cable connections during the first phase of the cabling. It will have at least one F1TDC and one fADC125. For the crate and the LV power supplies we may need 208V and therefore we will move the transformer there. We expect the racks to be powered in several weeks from now.

- Nick now has all the LV and signal cables, except for the spare signal cables for package 1.

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