Difference between revisions of "Minutes-1-3-2013"

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(Created page with "January 3, 2013 FDC meeting = Agenda = # Production [http://www.jlab.org/Hall-D/detector/fdc/production/FDC_Construction_January_3_2012.xlsx Construction Tracking] (Dave) # Corr...")
 
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= Agenda =
 
= Agenda =
# Production [http://www.jlab.org/Hall-D/detector/fdc/production/FDC_Construction_January_3_2012.xlsx Construction Tracking] (Dave)
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# Production [http://www.jlab.org/Hall-D/detector/fdc/production/FDC_Construction_January_3_2013.xlsx Construction Tracking] (Dave),[http://www.jlab.org/Hall-D/detector/fdc/photographs/three_packages.jpg picture of the three packages]
 
# Corrosion [http://www.jlab.org/Hall-D/detector/fdc/corrosion/Spreadsheet.pdf tests] (Lubomir)
 
# Corrosion [http://www.jlab.org/Hall-D/detector/fdc/corrosion/Spreadsheet.pdf tests] (Lubomir)
 
# Engineering (Bill)  
 
# Engineering (Bill)  
 
# Electronics (Chris, Nick)
 
# Electronics (Chris, Nick)
# Tests at EEL126 [https://halldweb1.jlab.org/elog-halld/FDC FDC E-log]
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# Tests at EEL126 [https://halldweb.jlab.org/elog-halld/FDC FDC E-log]
 
# Other
 
# Other
 
<!--
 
  
 
= Minutes =
 
= Minutes =
  
Participants: Eugene, Bill, Dave, Chris, Nick, Simon, Beni, and Lubomir.
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Participants: Eugene, Bill, Dave, Chris, Nick, and Lubomir.
  
 
== Production ==
 
== Production ==
  
- Dave: priority is to finish the two type-3 cathodes so that we can build three cells from package #2. The first type-3 will be ready on Monday, then we can start the  installation. Working on all the other cathodes for this package. Since Tina and Mike will start working also on BCAL we'll have to find a way to finish at least the package#2 cathodes, that has to be done by the end of January.  
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- Picture done before Christmas of the the packages #4,1,3 (front to back) is linked above. Now we have also the colling loops installed on package #4, HV wiring done, tomorrow Chris and Nick will finish the HV connectors and the package will be ready for testing at EEL126. What's not in the picture: package #2 with three cells assembled. All four packages were flushed  with Nitrogen over the holidays and yesterday we switched the gas to Ar/CO2 mixture for package #2, will start testing it next week.
  
- Package #4: the broken wire (top cell) was replaced and the package put together last Friday. This week the top cell was tested: all channels working fine, very low currents of 15/-4nA, oxygen after six days flushing ~160ppm. The plan is to take the package from the installation table and start putting the other subsystems. The problem is that we still don't have the clips.
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- Dave: working on the last two cathodes (#75-76) needed for the last production package #2: installing, testing, gluing daughter cards on them. Also working on three spare cathodes. Casey started gluing a new spare wire frame; glued the PCB ring, now ready for lamination. We have PCBs for one more wire frame. Mike will no longer work for us (accepted a position at the cryo-group), still will have enough manpower (Dave) to finish the FDC production.  
  
- All the subsystems on package #1 were installed.
+
- We had issues with the HVAC for the clean room starting yesterday in the morning (most likely) and this morning a steam hose in the HVAC broke that was replaced by Dave. Ron Bartec said that due to power glitch the AC stopped working. Since the humidity in the bay area was low enough we never got humidity above 43% inside the clean room. The temperature there didn't exceed 74 deg. They fixed the problem and now everything is going back to normal.
  
- Package #3: as explained in entry #98, the package was connected to the Nitrogen dewar with a rotameter at 30sccpm, and there was an over-pressure over the last weekend. We measured the pressure at the output of the rotameter: 360Pa, so the pressure in the chamber must have been lower than that.
+
== Cathode corrosion test ==
  
== Electronics ==
+
- Lubomir: test #3 (Ar/CO2 gas, at ~70degC) is completed, see the final spreadsheet attached. Before Christmas the second EPDM sample failed, we stopped the test and opened the vacuum chamber. It turned out all the samples have low resistance at the place of the O-rings and all the samples that failed were due to higher resistance on the trace next to the soldering point. The main conclusion from this test is that there are problems doing conventional soldering on 2 microns copper traces and that these problems appear most likely before the corrosion we want to study. Therefore we need different experimental set-up if we want to continue with these tests. Interestingly, we never had soldering problems when using Apiezon, probably it leaked over and covered the soldering place thus preventing its damage.
  
- Chris: delay with the clips due to lack of material. They made only 135 (out of 500) and Chris asked them to ship these; plus about 50 here could be enough for one package. Nick populated one more set of PCB and will do another (the last) one soon. Chris and Nick finished the HV cabling on package #1.
+
- Measuring the resistance on the trace where the O-ring sample was placed turned out to be tricky. This is due to a non-conductive layer that has developed somehow on the top of the copper close to the O-ring, so one needs a pin that will go through that layer but will make contact to the thin copper trace. Using this measurement technique Lubomir re-checked the samples that failed before. The EPDM sample from the second test that failed after 12 days at 100 deg C and 100% humidity turned out to be really corrosion below the EPDM material. However, the two EPDM samples from the first test that failed after 8-10 days showed low resistance at the trace below the EPDM; this has to be confirmed with Vlad since there were mistakes with sample labeling. In any case using the results from the three tests and assuming the activating energy is the same for the different conditions, one can put a '''lower limit for the corrosion problem''' to appear when using EPDM+Viton: '''2.6 (-1.1/+2.4) years'''.
  
- According to Beni, Cody made progress in coding the firmware for fADC125 and will do some tests in 126.
+
== Engineering ==
  
== Cathode corrosion test ==
+
- Bill: working to reduce the price of the package spacers, didn't gain a lot, will stick to the old design. Fluorinert is here, the chiller will come Jan. 17.
  
- Lubomir: test #3 (Ar/CO2 gas, at ~70degC). One more sample failed over the weekend, 25 days after the start of the test: one of the two Viton samples, second Viton is OK. Again we suspect it is the solder that failed.
+
- Bill is designing a set-up to test the cooling. Will use a tube to make one loop with 22 pre-amps clamped to the tube, powered with LV, and somehow insulated using styrofoam (Bill) or just covering the pre-maps with bags (Eugene) to simulate the lack of air-flow. Nick: the test can be done in 117, he has LV for 22 channels there.  
  
== Engineering ==
+
- Bill also wanted to test the tool for the manifold installation on the cooling loops in the packages; it is used to cut the tubes at the right place and then install the manifolds. He wanted to try it first on cooling loops not installed on the package, but Dave suggested that we can do it on the third package since there in any case we have to remove the cooling loops (the tube splittings there are not at the correct positions).  
 
+
- Bill ordered fiducial stuff the parts for the package spacers. All the parts for the cooling, except the chiller, are here. Will talk to the survey people about the details.  
+
 
+
- Bill complained about many corrupted files on the M-drive in the halld_engineering directory. Most of them have also files with the correct versions, but some, including several FDC procedures, don't.
+
  
 
== Tests at EEL126 ==
 
== Tests at EEL126 ==
  
- The two AC units in 126 are now installed, both the inside and outside parts, but not connected electrically; will happen next week.
+
- The two AC units in 126 are now operational set at 70deg. However, the remote control is at the facilities so we have to make request each time we want to change the setting. The problem is that the temperature in 126 is a result of both, the AC and the heater working at the same time. When it's colder outside there's more
 
+
heating and if the thermostat is in the AC unit it will not sense the temperature close to the heat blower that is just above the testing set-up.  
- Lubomir showed latest results for the wire resolution using the three-cathode configuration for the third package; details in the FDC Elog #99. After extracting experimentally the time-to-distance function using cathode information only, then the track can be reconstructed with a minimum number of cells. This first step is needed to find the offsets of all the wire planes. Then one can do the track fitting using all the planes except one (cell #2) on which we study the resolution. The residuals for cell #2 showed better resolution (second plot in #99), ~190 microns on average, than obtained before for cell #3. In case of cell #3 one had to take into account the strip resolution, and the value for that was too optimistic, this can explain the cell #2/3 resolution differences. Now the resolution is closer to that obtained with the prototype but without the time-to-distance conversion, except at big distances from the wire. There the field is not homogeneous and the statistics is very poor, both these can explain the problem.
+
 
+
- The offsets of the wires were found w.r.t. frame defined by cells #1 and #4 and they are: -282, -116, +409, +147 microns for cells #2,3,5,6. So, somehow cell #5 is off by 200-300 microns. By design this should not happen if the strong-back doesn't move w.r.t pin-rails. The strong-back is attached to the granite table with micrometers that are locked, but Dave said sometimes these needed to be adjusted. We discussed if the Beni's results about deviations from 60deg cell rotation may have the same origin and related questions about surveying and extracting the offsets from the data.
+
 
+
== Other ==
+
- Beni is working on the HV GUI for the FDC.
+
 
+
- Next FDC meeting will be January 3, due to the physics Christmas party next Thursday.
+
  
-->
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- We are planing to move the fourth package to 126 an Monday afternoon. Dave will coordinate this with the truck driver on Monday.

Latest revision as of 02:09, 1 April 2015

January 3, 2013 FDC meeting

Agenda

  1. Production Construction Tracking (Dave),picture of the three packages
  2. Corrosion tests (Lubomir)
  3. Engineering (Bill)
  4. Electronics (Chris, Nick)
  5. Tests at EEL126 FDC E-log
  6. Other

Minutes

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

Production

- Picture done before Christmas of the the packages #4,1,3 (front to back) is linked above. Now we have also the colling loops installed on package #4, HV wiring done, tomorrow Chris and Nick will finish the HV connectors and the package will be ready for testing at EEL126. What's not in the picture: package #2 with three cells assembled. All four packages were flushed with Nitrogen over the holidays and yesterday we switched the gas to Ar/CO2 mixture for package #2, will start testing it next week.

- Dave: working on the last two cathodes (#75-76) needed for the last production package #2: installing, testing, gluing daughter cards on them. Also working on three spare cathodes. Casey started gluing a new spare wire frame; glued the PCB ring, now ready for lamination. We have PCBs for one more wire frame. Mike will no longer work for us (accepted a position at the cryo-group), still will have enough manpower (Dave) to finish the FDC production.

- We had issues with the HVAC for the clean room starting yesterday in the morning (most likely) and this morning a steam hose in the HVAC broke that was replaced by Dave. Ron Bartec said that due to power glitch the AC stopped working. Since the humidity in the bay area was low enough we never got humidity above 43% inside the clean room. The temperature there didn't exceed 74 deg. They fixed the problem and now everything is going back to normal.

Cathode corrosion test

- Lubomir: test #3 (Ar/CO2 gas, at ~70degC) is completed, see the final spreadsheet attached. Before Christmas the second EPDM sample failed, we stopped the test and opened the vacuum chamber. It turned out all the samples have low resistance at the place of the O-rings and all the samples that failed were due to higher resistance on the trace next to the soldering point. The main conclusion from this test is that there are problems doing conventional soldering on 2 microns copper traces and that these problems appear most likely before the corrosion we want to study. Therefore we need different experimental set-up if we want to continue with these tests. Interestingly, we never had soldering problems when using Apiezon, probably it leaked over and covered the soldering place thus preventing its damage.

- Measuring the resistance on the trace where the O-ring sample was placed turned out to be tricky. This is due to a non-conductive layer that has developed somehow on the top of the copper close to the O-ring, so one needs a pin that will go through that layer but will make contact to the thin copper trace. Using this measurement technique Lubomir re-checked the samples that failed before. The EPDM sample from the second test that failed after 12 days at 100 deg C and 100% humidity turned out to be really corrosion below the EPDM material. However, the two EPDM samples from the first test that failed after 8-10 days showed low resistance at the trace below the EPDM; this has to be confirmed with Vlad since there were mistakes with sample labeling. In any case using the results from the three tests and assuming the activating energy is the same for the different conditions, one can put a lower limit for the corrosion problem to appear when using EPDM+Viton: 2.6 (-1.1/+2.4) years.

Engineering

- Bill: working to reduce the price of the package spacers, didn't gain a lot, will stick to the old design. Fluorinert is here, the chiller will come Jan. 17.

- Bill is designing a set-up to test the cooling. Will use a tube to make one loop with 22 pre-amps clamped to the tube, powered with LV, and somehow insulated using styrofoam (Bill) or just covering the pre-maps with bags (Eugene) to simulate the lack of air-flow. Nick: the test can be done in 117, he has LV for 22 channels there.

- Bill also wanted to test the tool for the manifold installation on the cooling loops in the packages; it is used to cut the tubes at the right place and then install the manifolds. He wanted to try it first on cooling loops not installed on the package, but Dave suggested that we can do it on the third package since there in any case we have to remove the cooling loops (the tube splittings there are not at the correct positions).

Tests at EEL126

- The two AC units in 126 are now operational set at 70deg. However, the remote control is at the facilities so we have to make request each time we want to change the setting. The problem is that the temperature in 126 is a result of both, the AC and the heater working at the same time. When it's colder outside there's more heating and if the thermostat is in the AC unit it will not sense the temperature close to the heat blower that is just above the testing set-up.

- We are planing to move the fourth package to 126 an Monday afternoon. Dave will coordinate this with the truck driver on Monday.