Difference between revisions of "Minutes-10-18-2012"

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= Minutes =
 
= Minutes =
  
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Participants: Fernando, Eugene, Bill, Dave, Nick, Vlad, Simon, Beni, and Lubomir. This was the longest "short" meeting (Dave).
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Participants: Eugene, Bill, Dave, Chris, Nick, Vlad, Simon, Beni, and Lubomir.
  
 
== Production ==
 
== Production ==
  
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- Dave: Fourth cell of the first package was installed yesterday, today we put a cathode from the fifth cell, tomorrow we plan to finish also the last cell.
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- Dave: The the first package was assembled completely on Friday. Due to delays with the bas bottles (again GTS company), we started flushing with Nitrogen. Will have the bottles by the end of the next week hopefully. Anatoly is working on the cathodes for package #4. All but one are ready. Wire frame #29 will be deadened on Monday. Need Casey and Mike for several hours to string wire frame #30. These frames are neede for package #4 as well. PO for the foils was issued yesterday, expect them Nov 15, then Anatoly will start testing them. We need the foils for package #2 sometime in December.  
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We are using the six spare cathodes made at the end of the production. The last cathode (#58) to finish the package needs the cards glued on it. Wire frame #29 is ready, except wire deadening. Wire frame #30 is on the stringing table, we will have Casey and Mike later in the month to string it.
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- Now we are at most four people at Blue Crab: Dave, Anatoly, Vlad, and Lubomir. Moving the cathodes with the vacuum fixture require four people.
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- Vlad started applying HV on the new cells: could not reach more than ~1800V on two of the new cells. We suspect that the limitation comes from the gas, Nitrogen. We will try the same on a cell that worked before.  
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- Eugene: what needs to be ordered till the end of the FDC production. Dave: rigid-flex population (connectors ordered), grounding clamps, plus consumables. All the rest has been ordered.  
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== Cathode corrosion ==
 
== Cathode corrosion ==
  
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- Vlad showed results of the tests in the vacuum chamber at high temperature (~100degC) where all the samples (cathode traces 0.5mm wide) have wires soldered and he measures their resistance continuously without opening the chamber. Using gas, the EPDM sample showed >1MOhm resistance after 8-10 days, which translated to room temperature is ~100 days or more depending on the activation energy. No changes in the Viton, and Viton+Apiezon resistance after 15 days. New tests started with air at 100degC and 100% humidity. No effects yet after 3.5 days.
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- Vlad showed new results of the tests in the vacuum chamber at high temperature (~100degC), high humidity (~100%) in air. One of the samples showed >1MOhm after 4 days, while the other two are OK after 11 days. We have three samples, EPDM, Viton, and Viton+Apiezon, but the experiment was blinded, so we don't know which is which.  
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- Eugene: humidity doesn't seem to be such important factor; if that's the case the gas itself can contribute significantly to the corrosion? But then one has to explain the Viton/ EPDM difference, and why the corrosion happens at the O-ring. Eugene proposed to do also experiment in air but at low humidity. In the moment the priority of the studies is to investigate the Viton+Apiezon samples at worse possible conditions and then translate the results to the hall conditions.
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- Dave found that the CO2 used by the gas company to make our mixture at Blue Crab is grade 3 (Argon is grade 5), meaning contaminations can be at 0.1% level and are not defined. Dave will talk to the company and fix this.
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== Engineering ==
 
== Engineering ==
  
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- Bill proposes an off-shell Temperature Control Unit (document linked above) to be used in the FDC cooling system. The unit is designed for Fluorinert and is ready for use. It will need probably some extra stuff, like flowmeters to detect leakages, RTDs to monitor the temperature, but in general it will work. Bill had some concerns also about the type of the pump used, that can create high pressure, so one has to find a way to control it, as well. The price is similar to the designed unit, that was supposed to be made at home. After some discussions Eugene agreed the off-shell Unit to be purchased: it will save time.
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- Bill made proposes an off-shell Temperature Control Unit
  
 
- What will happen if the Unit fails? Fernando: the voltage regulator on the pre-amp card has over-current and over-temperature protection, i.e. it will shut off the power to the card. In addition the control system should shut off the LV if the Temperature Control Unit doesn't work.
 
- What will happen if the Unit fails? Fernando: the voltage regulator on the pre-amp card has over-current and over-temperature protection, i.e. it will shut off the power to the card. In addition the control system should shut off the LV if the Temperature Control Unit doesn't work.

Revision as of 18:33, 18 October 2012

October 11, 2012 FDC meeting

Agenda

  1. Production Construction Tracking (Dave)
  2. Corrosion tests (Vlad)
  3. Engineering (Bill)
  4. Electronics (Chris, Nick)
  5. Third package tests FDC E-log (Beni)
  6. Other


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