Difference between revisions of "Minutes-11-17-2011"

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(Created page with "November 17, 2011 FDC meeting = Agenda = # Production [http://www.jlab.org/Hall-D/detector/fdc/production/FDC_Construction_November_10_2011.xlsx Construction Tracking] (Dave) #...")
 
(Production)
 
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= Agenda =
 
= Agenda =
  
# Production [http://www.jlab.org/Hall-D/detector/fdc/production/FDC_Construction_November_10_2011.xlsx Construction Tracking] (Dave)
+
# Production [http://www.jlab.org/Hall-D/detector/fdc/production/FDC_Construction_November_17_2011.xlsx Construction Tracking] (Dave)
 
#* Production update
 
#* Production update
 
#* Second package tests (Lubomir)
 
#* Second package tests (Lubomir)
# Engineering update; [http://www.jlab.org/Hall-D/detector/fdc/drawings/fdc_calculations4.xlsx card positions] (Bill)   
+
# Engineering update (Bill)   
# Electronics update (Chris); [http://www.jlab.org/Hall-D/detector/fdc/drawings/FDC_PREAMP_LOCATIONS.xlsx Fernado's LV scheme]
+
# Electronics update (Chris)
# Test set-up at EEL126 [http://www.jlab.org/Hall-D/detector/fdc/OSP/fdc_osp.pdf OSP],[http://www.jlab.org/Hall-D/detector/fdc/OSP/taskhazardanalysis.pdf THA], [(Beni)
+
#* [http://www.jlab.org/Hall-D/detector/fdc/drawings/FDC_PREAMP_LOCATIONS.xlsx LV cabling]
 +
# Chamber testing at 126
 
# [http://www.jlab.org/Hall-D/detector/fdc/tdr/tdr.pdf TDR] (Lubomir)  
 
# [http://www.jlab.org/Hall-D/detector/fdc/tdr/tdr.pdf TDR] (Lubomir)  
# Other: [https://halldweb1.jlab.org/elog-halld/ new FDC logbook]
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# Other
 
+
<!--
+
  
 
= Minutes =
 
= Minutes =
  
Participants: Eugene, Bill, Dave, Chris, Simon, Vladimir, Beni, and Lubomir.   
+
Participants: Eugene, Bill, Dave, Chris, Simon, Vladimir, and Lubomir.   
  
 
== Production ==
 
== Production ==
  
- Dave on second package production: first cell was installed, all the elements for the second cell are ready except to populate the wire boards (Chris will do it tomorrow). Cathodes for the third cell also ready, working on the fourth cell cathodes. Third wire plane was strung and wires glued and soldered. The HV caps were replaced on the fourth, but we have problems so far with the dark current there; may require additional change of some capacitors. The fifth wire frame was laminated today. Problems with field wire spools, Dave will discuss it with Steve Christo from Hall B.  
+
- Dave: second cell of the second package was installed. Third wire plane will be populated tomorrow by Chris and we will try to install the third cell by the end of the day. Working on the fourth and fifth cell cathodes. The fourth wire frame on which Dave replaced the caps, is being tested with HV by Anatoly (see below). It delayed the wire stringing by one week so far. The fifth wire frame was laminated.  
  
- Lubomir: The installation of the first cell was much easier due to the new hubs/pins Bill designed. Flushing with gas since Tuesday, chamber is very tight (bubbles at as low as 15 ccpm). Setting HV on it was also easy. Vladimir tested all the channels with a scope and 55Fe: all working fine. But again, we see a noise at the same place (around HV trace on the fourth +HV sector) we saw on three cells in the first package, this time with higher frequency (~2.5 kHz). Will rotate the top cathode by 30deg after the meeting  to make sure we have the same problem here.
+
- Discussions about the noise coming from a HV trace initiated by Eugene. We know the noise is coming from a HV trace on the back of the PCB. The amplitude of the noise is close to that of the standard signals, but is random with a frequency of <3kHz and width of ~20ns. So, the probability for interfering with the signals is <0.3% say for 1us window, so negligible. Starting with the sixth wire frame we are going to apply additional conformal coating (like the green coating on the PCBs) on the eight HV traces.
 +
 
 +
- Lubomir about the HV cap tests on the fourth wire frame: after replacing the caps last week and some conditioning we were able to get leakage current of 100-300nA initially but it later increased up to several uA. Anatoly replaced/fixed ~10 caps and the current went down to few tens of nA but still it was increasing after that. Normally, the initial current is high and then it goes down, opposite to what we see with this frame. This is the second frame on which we use 3kV rated caps and we had no issues like this with the first one. Also, Anatoly tested 37 of these 3kV caps separately and they didn't show such increase of the current with the time. Eugene: if the problem is in the 3kV caps we better wait for the 4kV capacitors (will have them hopefully in January!). We decided to continue with the HV tets: leave the frame under HV overnight and see if it will stabilize, then tomorrow morning will decide if we want to replace all the caps once more and then do more tests over the weekend. Then finally on Monday we should be in a position to decide if we will wait for the 4kV capacitors.
 +
 
 +
- Vladimir about the second cell tests: all channels working fine with a source. No noise on the second cell at the place where we found it on the other cells (as discussed above), but some kind of low frequency noise at a place close to another HV trace to be studied further.
  
 
== Engineering ==
 
== Engineering ==
  
- The scheme for the positions of the signal connectors in the package is linked above
+
- Bill: looking how to seal the cooling tube when using Fluorinert; will prototype with a many-fold. Rest of the gusset rings will be ready by January.
 +
 +
- Tests with DP460: samples were made with 2 mil and 0.5 mil Al-mylar glued on un-roughed g10. After one day curing, no evidence DP460 is better than Hysol we are using now. Will wait more and also do samples with roughed g10 and with Rohacell to repeat the CMU samples. 
  
- Bill: will look into the cooling system. Using Fluorinert (FC-72 made by 3M) instead of water require proper sealing. We discussed if we will need real cooling for the 126 tests, or just the tubing.
+
- Bill discussed also if we need to keep our equipment in 126 warm, since the heating will be down for a week during Christmas. We will not move the first package before Christmas. Beni should decide if some heating is needed for the equipment there.
  
 
== Electronics ==
 
== Electronics ==
  
- Chris is ready with the first 22 pre-amps that handed to us at the meeting. Cody will test the rest with a LabView system; working on the program now. Will install the pre-amps and the first cooling tube on the first package tomorrow.
+
- Chris finished testing card for the mass pre-amp tests. Made a cable to be used with the translator boards.
  
- Based on the Bill's drawing of the pre-amp cards, Fernanda made a scheme for the low voltage cables, also linked above. Will have 4 cards per cable.
+
- LV cables: Anodes: spacing must be 2.75" (instead of 5") between the two connectors. Vladimir tested all the cathode groups with a mock-up cable. In two groups the 10-5-10" cable didn't work, but one was able to re-group the cards in such a way that 10-5-10" is long enough to be used everywhere. Prototype helped to understand that in most of the groups you have excessive length and only for a few you need the full length. Eugene insisted that we need to work more in optimizing the LV cabling by increasing the number of cable types so that we don;'t have excessive cables inside the detector. Bill and Vladimir will work on that.
 +
 
 +
- HV cabling: we need to start prototyping the cabling on the first package. Need the two connectors attached to the holding brackets and start soldering the individual wires to them. Chris needs schematics from Fernando.
  
 
== Chamber testing at 126  ==
 
== Chamber testing at 126  ==
  
- Beni: working on the OSB and THA for the tests at 126 (latest version linked above). Some leakage on an Indiana chamber, made temporary fix. The materials for the translator boards are here, now writing PR for their assembly.  
+
- Eugene: when do you plan the testing to start? Main showstopper (apart form the fADC125) is the translator board. According to Chris it's not a problem to make 6 LV cables and two HV cables needed for the restricted (wires only) package tests.  
  
 
== TDR ==
 
== TDR ==
  
- Slow progress, current version is at the link above. Need drawings from Bill of the wire and cathode frames. Simon working on the tracking section. Eugene: the document should be self contained as much as possible, i.e. important info must be in the document not cited.  
+
- Slow progress, including now drawings from Bill, current version linked above. Lubomir will have a very preliminary version by Thanksgiving and Simon will continue working on it.  
  
 
== Other ==
 
== Other ==
  
- Beni setup a new logbook to be used for the FDC (see link above).
+
- Lubomir in vacations for three weeks after Thanksgiving. Will ask Beni for at least one meeting to be scheduled on Dec 8. If needed more will be scheduled.
 
+
-->
+

Latest revision as of 11:45, 18 November 2011

November 17, 2011 FDC meeting

Agenda

  1. Production Construction Tracking (Dave)
    • Production update
    • Second package tests (Lubomir)
  2. Engineering update (Bill)
  3. Electronics update (Chris)
  4. Chamber testing at 126
  5. TDR (Lubomir)
  6. Other

Minutes

Participants: Eugene, Bill, Dave, Chris, Simon, Vladimir, and Lubomir.

Production

- Dave: second cell of the second package was installed. Third wire plane will be populated tomorrow by Chris and we will try to install the third cell by the end of the day. Working on the fourth and fifth cell cathodes. The fourth wire frame on which Dave replaced the caps, is being tested with HV by Anatoly (see below). It delayed the wire stringing by one week so far. The fifth wire frame was laminated.

- Discussions about the noise coming from a HV trace initiated by Eugene. We know the noise is coming from a HV trace on the back of the PCB. The amplitude of the noise is close to that of the standard signals, but is random with a frequency of <3kHz and width of ~20ns. So, the probability for interfering with the signals is <0.3% say for 1us window, so negligible. Starting with the sixth wire frame we are going to apply additional conformal coating (like the green coating on the PCBs) on the eight HV traces.

- Lubomir about the HV cap tests on the fourth wire frame: after replacing the caps last week and some conditioning we were able to get leakage current of 100-300nA initially but it later increased up to several uA. Anatoly replaced/fixed ~10 caps and the current went down to few tens of nA but still it was increasing after that. Normally, the initial current is high and then it goes down, opposite to what we see with this frame. This is the second frame on which we use 3kV rated caps and we had no issues like this with the first one. Also, Anatoly tested 37 of these 3kV caps separately and they didn't show such increase of the current with the time. Eugene: if the problem is in the 3kV caps we better wait for the 4kV capacitors (will have them hopefully in January!). We decided to continue with the HV tets: leave the frame under HV overnight and see if it will stabilize, then tomorrow morning will decide if we want to replace all the caps once more and then do more tests over the weekend. Then finally on Monday we should be in a position to decide if we will wait for the 4kV capacitors.

- Vladimir about the second cell tests: all channels working fine with a source. No noise on the second cell at the place where we found it on the other cells (as discussed above), but some kind of low frequency noise at a place close to another HV trace to be studied further.

Engineering

- Bill: looking how to seal the cooling tube when using Fluorinert; will prototype with a many-fold. Rest of the gusset rings will be ready by January.

- Tests with DP460: samples were made with 2 mil and 0.5 mil Al-mylar glued on un-roughed g10. After one day curing, no evidence DP460 is better than Hysol we are using now. Will wait more and also do samples with roughed g10 and with Rohacell to repeat the CMU samples.

- Bill discussed also if we need to keep our equipment in 126 warm, since the heating will be down for a week during Christmas. We will not move the first package before Christmas. Beni should decide if some heating is needed for the equipment there.

Electronics

- Chris finished testing card for the mass pre-amp tests. Made a cable to be used with the translator boards.

- LV cables: Anodes: spacing must be 2.75" (instead of 5") between the two connectors. Vladimir tested all the cathode groups with a mock-up cable. In two groups the 10-5-10" cable didn't work, but one was able to re-group the cards in such a way that 10-5-10" is long enough to be used everywhere. Prototype helped to understand that in most of the groups you have excessive length and only for a few you need the full length. Eugene insisted that we need to work more in optimizing the LV cabling by increasing the number of cable types so that we don;'t have excessive cables inside the detector. Bill and Vladimir will work on that.

- HV cabling: we need to start prototyping the cabling on the first package. Need the two connectors attached to the holding brackets and start soldering the individual wires to them. Chris needs schematics from Fernando.

Chamber testing at 126

- Eugene: when do you plan the testing to start? Main showstopper (apart form the fADC125) is the translator board. According to Chris it's not a problem to make 6 LV cables and two HV cables needed for the restricted (wires only) package tests.

TDR

- Slow progress, including now drawings from Bill, current version linked above. Lubomir will have a very preliminary version by Thanksgiving and Simon will continue working on it.

Other

- Lubomir in vacations for three weeks after Thanksgiving. Will ask Beni for at least one meeting to be scheduled on Dec 8. If needed more will be scheduled.