Difference between revisions of "Minutes-1-5-2012"

From GlueXWiki
Jump to: navigation, search
(Chamber testing at 126)
 
(9 intermediate revisions by the same user not shown)
Line 9: Line 9:
 
#* Cooling system
 
#* Cooling system
 
# Electronics update (Chris)
 
# Electronics update (Chris)
 +
#* Pre-amp cards
 +
#* HV cabling
 +
#* Grounding (Lubomir)
 
#* LV cabling [http://www.jlab.org/Hall-D/detector/fdc/electronics/LVscheme.pdf Vlad's scheme]
 
#* LV cabling [http://www.jlab.org/Hall-D/detector/fdc/electronics/LVscheme.pdf Vlad's scheme]
 +
# Testing in 126 (Beni)
 
# [http://www.jlab.org/Hall-D/detector/fdc/tdr/tdr.pdf TDR] (Simon)  
 
# [http://www.jlab.org/Hall-D/detector/fdc/tdr/tdr.pdf TDR] (Simon)  
 
# Other
 
# Other
 
<!--
 
  
 
= Minutes =
 
= Minutes =
  
Participants: Eugene, Bill, Dave, Chris, Simon, Vladimir, and Lubomir.   
+
Participants: Bill, Dave, Chris, Mark, Simon, Beni (ESNET), Eugene, and Lubomir.   
  
 
== Production ==
 
== 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.  
+
- Dave for the last cell of the second package: a field wire was replaced on the wire plane yesterday to be cleaned today, daughter cards were glued on the type-2 cathode today, type-1 cathode is ready. Tomorrow we will have all the parts of the last cell ready for testing and installation. Next cell (for third package): wire frame was laminated, type-1 cathode ready, working on the flaps for the type-2 cathode. For the nex wire frame lamination we will use a board with the vias not sealed (we have several of this kind); Bill suggested using Hysol to cover the vias right after lamination.
  
- 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. 
+
- The fifth cell of the second package was installed right before the break and was tested this week successfully. It took long time (~10 days) to condition the chamber: Epon didn't dry as usual or gas flow was too low during the break?
 
+
- 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 ==
  
- 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.
+
- Bill showed pictures for different parts of the cooling system: pump, manifold. The pump is supposed to operate at ~100psi. The coolant (Fluorinert) is heavier (1.73g/cm^3) than watter.  
 
   
 
   
- 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.  
+
- Cu tubing: by directly measuring the weight of a tube piece we found the tube is heavier than what was used in the simulations. Later it turned out that the tubing was simulated correctly, according to the specifications for the tube sizes: 4mm OD and 2.79mm ID. For 4mm OD and Cu density of 8.96 g/cm^3  from the weight measurements one gets 2.14mm ID. After the meeting direct ID measurements confirmed the specified 2.79mm. The only explanation so far is that the density of the tube material is higher.  
  
- 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.
+
- We discussed if we need additional hubs and pins to assemble the last two packages, or we can re-use some of those from the already assembled packages. We need the hubs for the tests in 126 (to attach the strongback).
  
 
== Electronics ==
 
== Electronics ==
  
- Chris finished testing card for the mass pre-amp tests. Made a cable to be used with the translator boards.
+
- Chris: made 4 more pre-amp sets (22 each) for the remaining cells in the first package. Will do one more set to be installed on the second package for testing purposes. All the pre-amps will be tested by Cody and likely will have them next week.
  
- 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.
+
- Chris will make the HV connections on the first package next week; before that we have to do the labeling.
  
- 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.
+
- Vlad came with a scheme for the cathode LV cables: three types with distances between the four connectors of 8-3-8, 6-3-3, and 3-3-3 inches.
 +
In addition will have anode LV cables with two connectors 2.75" apart. We discussed how to label the connectors/cables to help their installation. Certainly color coding will be used for the different cable types, but we need also labels (difficult to be put on these connectors).
  
== Chamber testing at 126 ==
+
- Grounding: it turned out that measuring the resistance with probes directly on the pre-amp clamps (coated aluminum) gives strange results, but when we measured it between the Cu tubes and the pre-amp card it turned out to be practically zero. In this case the grounding with the Cu tube is an option that has to be tested in 126 and compared to the scheme when using separate ground clamps and wires/braided ground straps. 
  
- 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.
+
== Testing at 126  ==
  
== TDR ==
+
- Beni asked if the flat cables for the translation cards are ready. Chris will work on them after he's done with the other stuff.
  
- 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.  
+
- Strip grounding: since we will have all the pre-amp installed we discussed different options. Will just applying LV put the strips to ground potential? If yes, we need LV cables. Beni proposed using Al or Cu tape at the pre-amp connector, or (Chris) just put female connector on the pre-amp with the pins at the other side taped; then we need 108 connectors. Has to be discussed with Fernando.
  
== Other ==
+
== TDR ==
 
+
- 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.
+
  
-->
+
- Simon worked before the holidays on the introduction. He included also GARFIELD simulations for different gas mixtures and with/without magnetic field that will be moved to the "Gas consideration" section. Lubomir will continue working on the package subsystems and asked Bill and Dave for some additional pictures.

Latest revision as of 19:30, 5 January 2012

January 5, 2012 FDC meeting

Agenda

  1. Production Construction Tracking (Dave)
    • Production update
    • Second package tests (Lubomir)
  2. Engineering update (Bill)
    • Cooling system
  3. Electronics update (Chris)
    • Pre-amp cards
    • HV cabling
    • Grounding (Lubomir)
    • LV cabling Vlad's scheme
  4. Testing in 126 (Beni)
  5. TDR (Simon)
  6. Other

Minutes

Participants: Bill, Dave, Chris, Mark, Simon, Beni (ESNET), Eugene, and Lubomir.

Production

- Dave for the last cell of the second package: a field wire was replaced on the wire plane yesterday to be cleaned today, daughter cards were glued on the type-2 cathode today, type-1 cathode is ready. Tomorrow we will have all the parts of the last cell ready for testing and installation. Next cell (for third package): wire frame was laminated, type-1 cathode ready, working on the flaps for the type-2 cathode. For the nex wire frame lamination we will use a board with the vias not sealed (we have several of this kind); Bill suggested using Hysol to cover the vias right after lamination.

- The fifth cell of the second package was installed right before the break and was tested this week successfully. It took long time (~10 days) to condition the chamber: Epon didn't dry as usual or gas flow was too low during the break?

Engineering

- Bill showed pictures for different parts of the cooling system: pump, manifold. The pump is supposed to operate at ~100psi. The coolant (Fluorinert) is heavier (1.73g/cm^3) than watter.

- Cu tubing: by directly measuring the weight of a tube piece we found the tube is heavier than what was used in the simulations. Later it turned out that the tubing was simulated correctly, according to the specifications for the tube sizes: 4mm OD and 2.79mm ID. For 4mm OD and Cu density of 8.96 g/cm^3 from the weight measurements one gets 2.14mm ID. After the meeting direct ID measurements confirmed the specified 2.79mm. The only explanation so far is that the density of the tube material is higher.

- We discussed if we need additional hubs and pins to assemble the last two packages, or we can re-use some of those from the already assembled packages. We need the hubs for the tests in 126 (to attach the strongback).

Electronics

- Chris: made 4 more pre-amp sets (22 each) for the remaining cells in the first package. Will do one more set to be installed on the second package for testing purposes. All the pre-amps will be tested by Cody and likely will have them next week.

- Chris will make the HV connections on the first package next week; before that we have to do the labeling.

- Vlad came with a scheme for the cathode LV cables: three types with distances between the four connectors of 8-3-8, 6-3-3, and 3-3-3 inches. In addition will have anode LV cables with two connectors 2.75" apart. We discussed how to label the connectors/cables to help their installation. Certainly color coding will be used for the different cable types, but we need also labels (difficult to be put on these connectors).

- Grounding: it turned out that measuring the resistance with probes directly on the pre-amp clamps (coated aluminum) gives strange results, but when we measured it between the Cu tubes and the pre-amp card it turned out to be practically zero. In this case the grounding with the Cu tube is an option that has to be tested in 126 and compared to the scheme when using separate ground clamps and wires/braided ground straps.

Testing at 126

- Beni asked if the flat cables for the translation cards are ready. Chris will work on them after he's done with the other stuff.

- Strip grounding: since we will have all the pre-amp installed we discussed different options. Will just applying LV put the strips to ground potential? If yes, we need LV cables. Beni proposed using Al or Cu tape at the pre-amp connector, or (Chris) just put female connector on the pre-amp with the pins at the other side taped; then we need 108 connectors. Has to be discussed with Fernando.

TDR

- Simon worked before the holidays on the introduction. He included also GARFIELD simulations for different gas mixtures and with/without magnetic field that will be moved to the "Gas consideration" section. Lubomir will continue working on the package subsystems and asked Bill and Dave for some additional pictures.