Difference between revisions of "Minutes-9-5-2013"

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August 29, 2013 FDC meeting
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September 5, 2013 FDC meeting
  
 
= Agenda =
 
= Agenda =
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# Engineering (Bill)
 
# Engineering (Bill)
 
# Electronics (Chris, Nick)
 
# Electronics (Chris, Nick)
# Tests at EEL126
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# Tests at EEL126 [http://www.jlab.org/Hall-D/detector/fdc/photographs/Final_FDC_Test_Vlad.JPG]
 
# Other
 
# Other
  
<!--
 
  
 
= Minutes =
 
= Minutes =
  
Participants: Bill, Eugene, Chris, Simon, Vlad, and Lubomir.
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Participants: Bill, Dave, Chris, Nick, Simon, Vlad, Eugene, and Lubomir.
  
 
== Installation preparations ==
 
== Installation preparations ==
  
- Bill: for the cooling system in the Hall if the hard piping is not ready we can still have a temporary solution using plastic pipes. However, we need chill water supply.  
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- We discussed briefly the status in the Hall with respect to what is needed for the FDC installation. The electronics racks are on one side of the platform but not installed yet (Dave), rather just used as a template to mark the positions of the cable opening. After BCAL is installed the BCAL platform will be removed; for the cabling of the bottom of the FDC we will use something temporary there. At the same time the transformers should be installed there, but not clear how much space they will occupy.  
  
- Expectations are to start the FDC installation sometimes in October. Before that we need to install the skin and do some small fixes on the FDC: fix the HV connectors, replace a couple of pre-amps. Need also to connect the cooling system between the packages.  
+
- Gas system: nothing is in the Hall yet. There are penetration between the gas room and the Hall, but not yet to the gas bottles outside. The plan is to use plastic tubes from the gas room through the Hall to the detector. We want to check if using such a long plastic tubes will increase the Oxygen contamination. We can use the Oxygen sensor right now connected to the spare package. In the next weeks when Beni is back, we want to discuss the gas control with Narciso and Dave.
 +
 
 +
- Bill will check if the chilled water is readily available, and how and when the dry air system will be set-up.
 +
 
 +
- Bill attended a kind of QA readiness review for the FDC cabling. He explained the need to remove the four extra rails for the mesh; Tim agreed. One of the suggestion was to consult with Dr.Chandler about the ergonomics of the cabling (see the second picture attached above).
  
 
== Engineering ==
 
== Engineering ==
  
- Bill showed his new design of the mesh attachment using the main rails (drawings attached). Additional support at the end of the mesh, right between the CDC and FDC is needed; done with a stock T-shape Al profile (1/8"). Similar structure would be needed even with the old design using additional rails for the mesh attachment. The bearing for the mesh is glued to a holder. Same bearing is at the other (upstream) end of the mesh but it is removable. The drawings show also the plate connecting the packages and the grounding cable.
+
- The strips to connect the bearings of the four packages can be used as a ground connection and no additional ground cable is needed for that; Fernando agreed. We decided to have the strips plated for better surface conductivity. In addition Bill will use washers with teeth to connect to the bearing plates. It is not clear yet if one can use also the mesh as a ground connection. At the same time it may serve as a Faraday cage for the CDC!
  
- After testing the FDC with HV we will start working on the skin; the g10 sheets for that have been cut to the right sizes.  
+
- Bill and Dave will figure out when there will be a tech available to work on the skin: making slots on the g10 and cutting the plastic holders. We will need also Casey to install the tubing between the cooling manifolds.
  
== Tests at EEL126 ==
+
- Bill wants to test the new mesh support in the ESB. Only after that we will remove the four extra rails together with their holders on the installation carts.
  
- We started applying HV on the FDC package by package; will keep the HV for at least 24 hours on each. For that the flow was increased from 100ccpm total to 200ccpm or 50ccpm per package. Gas mixture is 40/60. All the packages were bubbling already at 25ccpm per package.
+
== Electronics ==
  
- While testing the top two cells of the spare package we had to increase the fADC samples up to 2500 resulting in a huge event size. This was a stress test for CODA: Beni, Elliot and others found a bug in CODA. Vlad is now analyzing the data from these cells at 40/60 Ar/CO2.
+
- Chris and Nick fixed the two HV connectors on package #2 that had several wires disconnected. Vlad tested the package with HV and all the sectors had signals.
  
- Vlad presented his results of analyzing the data from the top two cells with a scope at Blue Crab (talk attached above). He estimated the diffusion coefficient for 40/60 Ar/CO2 which turned out to be lower than the Garfield prediction at 100-200V/cm electric field. New results will come from the fADC data.
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== Tests at EEL126 ==
  
-->
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- Vlad finished testing the FDC packages with HV. He applies HV package by package and keep it for at least 24 hours. He checks two wire discriminator cards (15V threshold) in the middle of each cell. Each middle card has wires connected to two HV sectors. Thus, he checked that the positive HV is OK on all the sectors but there's no way to say if the negative is there too. Out of ~1k channels tested he found two noisy wires. Vald will keep the HV for longer time to see if the noise will disappear. It might be also due to the very low gas flow, 50ccpm per package to be compared to the nominal 250ccpm.

Latest revision as of 18:16, 11 September 2013

September 5, 2013 FDC meeting

Agenda

  1. Installation preparations [1]
  2. Engineering (Bill)
  3. Electronics (Chris, Nick)
  4. Tests at EEL126 [2]
  5. Other


Minutes

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

Installation preparations

- We discussed briefly the status in the Hall with respect to what is needed for the FDC installation. The electronics racks are on one side of the platform but not installed yet (Dave), rather just used as a template to mark the positions of the cable opening. After BCAL is installed the BCAL platform will be removed; for the cabling of the bottom of the FDC we will use something temporary there. At the same time the transformers should be installed there, but not clear how much space they will occupy.

- Gas system: nothing is in the Hall yet. There are penetration between the gas room and the Hall, but not yet to the gas bottles outside. The plan is to use plastic tubes from the gas room through the Hall to the detector. We want to check if using such a long plastic tubes will increase the Oxygen contamination. We can use the Oxygen sensor right now connected to the spare package. In the next weeks when Beni is back, we want to discuss the gas control with Narciso and Dave.

- Bill will check if the chilled water is readily available, and how and when the dry air system will be set-up.

- Bill attended a kind of QA readiness review for the FDC cabling. He explained the need to remove the four extra rails for the mesh; Tim agreed. One of the suggestion was to consult with Dr.Chandler about the ergonomics of the cabling (see the second picture attached above).

Engineering

- The strips to connect the bearings of the four packages can be used as a ground connection and no additional ground cable is needed for that; Fernando agreed. We decided to have the strips plated for better surface conductivity. In addition Bill will use washers with teeth to connect to the bearing plates. It is not clear yet if one can use also the mesh as a ground connection. At the same time it may serve as a Faraday cage for the CDC!

- Bill and Dave will figure out when there will be a tech available to work on the skin: making slots on the g10 and cutting the plastic holders. We will need also Casey to install the tubing between the cooling manifolds.

- Bill wants to test the new mesh support in the ESB. Only after that we will remove the four extra rails together with their holders on the installation carts.

Electronics

- Chris and Nick fixed the two HV connectors on package #2 that had several wires disconnected. Vlad tested the package with HV and all the sectors had signals.

Tests at EEL126

- Vlad finished testing the FDC packages with HV. He applies HV package by package and keep it for at least 24 hours. He checks two wire discriminator cards (15V threshold) in the middle of each cell. Each middle card has wires connected to two HV sectors. Thus, he checked that the positive HV is OK on all the sectors but there's no way to say if the negative is there too. Out of ~1k channels tested he found two noisy wires. Vald will keep the HV for longer time to see if the noise will disappear. It might be also due to the very low gas flow, 50ccpm per package to be compared to the nominal 250ccpm.