Difference between revisions of "Minutes-1-9-2014"

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= Agenda =
 
= Agenda =
−
# Installation [http://www.jlab.org/Hall-D/detector/fdc/installation/FDC_cabling_q1_1.JPG] (all)
+
# Installation [http://www.jlab.org/Hall-D/detector/fdc/installation/FDC_cabling_q1_1.JPG],[http://www.jlab.org/Hall-D/detector/fdc/installation/FDC_cabling_q1_2.JPG],[http://www.jlab.org/Hall-D/detector/fdc/installation/FDC_cabling_q1_3.JPG],[http://www.jlab.org/Hall-D/detector/fdc/installation/FDC_cabling_q1_4.JPG] (all)
−
# Engineering (Bill)
+
# Engineering [http://www.jlab.org/Hall-D/detector/fdc/installation/CDC_bearings_1.PNG], [http://www.jlab.org/Hall-D/detector/fdc/installation/CDC_bearings_2.PNG], [http://www.jlab.org/Hall-D/detector/fdc/installation/CDC_bearings_3.PNG] (Bill)
 
# Electronics (Chris, Nick)
 
# Electronics (Chris, Nick)
−
# Mini-DAQ [https://halldweb1.jlab.org/wiki/index.php/First_Tests_in_Hall-D] (Beni)
+
# Mini-DAQ [https://halldweb.jlab.org/wiki/index.php/First_Tests_in_Hall-D] (Beni)
 
# Other
 
# Other
  
−
<!--
 
  
 
= Minutes =
 
= Minutes =
  
−
Participants: Eugene, Bill, Nick, Chris, and Lubomir.
+
Participants: Eugene, Fernando, Dave, Nick, Chris, Simon, Bill, Beni, and Lubomir.
  
 
== Installation ==
 
== Installation ==
  
−
- Lubomir on the installation progress since the last meeting: all LV cables are connected to the detector and tested. The test was done by temporary connecting them to the LV panels. Now the cables are grouped in four big bundles (one per quadrant) and stored inside the mesh so that there's space to continue with the signal cables. Some of the labels on the pre-amps had to be corrected today and now we are ready to proceed with the signal cables. We will start with one quadrant of one package, test the connections and then continue with the next package. It is not clear yet if we want to connect the cables to the electronics before proceeding with the next package, but will decide as we go with the cabling.  
+
- One quadrant (top, left looking downstream) has been completely cabled at the detector side (see attached pictures), main work done by Mike Klopf (FEL) with the help of Shukui Zhan (FEL) and Lubomir. Now Nick, Robert (FEL) and Shukui are working on the connections at the electronics side. As of today Casey and Tina started cabling the right top side. Cabling procedure: starting with first package per quadrant, each 11 cables are grouped, total of three groups naturally following the pre-amp positions, and bundled together starting at the end of the mesh. In total there are 12 bundles that are then placed on the top cable tray and then the end is re-bundled according to the rack/crate positions.
  
−
- The HV was tested during the week just before the holidays: using 90/10 Ar/CO2 pre-mixed bottle and a flow of 400 ccpm as set on the mass flow controller; the packages were supplied in parallel. During the test three CAEN HV modules had to be replaced. The test was done by looking at one long strip per cell with a scope and turning on one HV sector at a time. We saw signals from all the HV sectors. Two of the HV channels in package 1(C1+HV3 and C4+HV2) were tripping every several hours (at +1600V). Another four HV channels (package 2 C6+HV3, C6+HV4 and package 4 C6+HV1, C6+HV2) started tripping when left over the night during the last days of the test. Different reasons for the trips were discussed: HV module, low flow (100 ccpm per package) combined with not so stable gas mixture (most likely), some bad cable connections due to the work on the LV connections and the installation of the prism holders. Plan for further tests: apply now HV since the FDC is being flushed with Nitrogen since the beginning of the Holidays; switch to 90/10 and test these with the Bertan HV supply (for that Nick will make a cable with SHV connector to be connected to the rectangular HV connector). Bill will work on a diving board to be used inside the mesh in case we want to access the individual HV connectors.
+
- In between, while the cables were on the floor, Anatoly tested all the cables at the electronics end with a scope using the translator board which allows to test only the first 8 and the last 8 channels from the 24 in the connector. There were four bad channels (small signals) in packages 3 and 4, most likely conductive tape issues. There's one card with all the channels showing a long shoulder in the signal, we suspect the pre-amp.
  
−
- We are also not sure if the mass flow controller works correctly. It is set to 400 ccpm but reads 459 ccpm. We measure the flow also with a rotameter which shows ~0.85 cfph (which is ~400ccpm) when using Ar/CO2 but shows 0.35 cfph when using Nitrogen.
+
- Since Friday last weak we switched the gas from Nitrogen to Ar/CO2 90/10. All the HV channels were OK till Tuesday evening when the same channels (that showed problems before Holidays) starting tripping from time to time. Right now one of the HV channels is really problematic tripping at >1400V (1600V is the nominal). Another four channels are tripping once per 8-24 hours. Certainly the trips are related to the gas. On Monday we expect to get the nominal gas mixture, 40/60.
  
 
== Engineering ==
 
== Engineering ==
  
−
- The cooling system was off during the Holidays. When we turned it on this morning the Fluorinert level was somewhat lower then before the Holidays. Bill is going to mark and check the level to see if there's some leakage.  
+
- Bill showed drawings (attached above) with the CDC bearings and attachment that require some space in between the two halves of the mesh. We wanted to put there three HV cables and a ground cable. Bill will get samples of these cable and look in place if they will fit there.  
  
−
- No results yet from the last survey done first week of December; Bill will talk to the survey group.  
+
- Bill is trying to figure out the problem with the mass flow controller and contacted the Brooks company. The flow is about a factor of 2 lower than the nominal, but we are not sure how reliable the flow controller is.
  
 +
- No results yet from the last survey done first week of December.
 +
 +
- Cathode scan: Bill will contact the company, expect a resolution of 100 microns which should be good enough because of the many measurements. Assumption is it will cost about few $k, Eugene agreed. The idea is to fit the scan results with a model with some free parameters that Simon will include in his alignment procedure.
 +
 
== Electronics ==
 
== Electronics ==
  
−
- Nick and Bill discussed the installation of the grounding cable, also in the Hall after the meeting.  
+
- Fernando, Bill, Nick and Chris discussed how to do the "HV return" connection to ground (one per HV connector): will be connected to the ground plate (see Bill's pictures above). There will be also one ground cable connected to one of the two ground plates. The "HV shield" (one per HV connector) should be connected to one shield cable coming from a wire frame. All the other shield (green) cables that are not used (10 per package) should be insulated.
  
−
- FDC cabling now has first priority, so Nick will make sure that the FEL people are available.
+
== Mini-DAQ ==
  
−
-->
+
- At the meeting Beni explained he's very close to get the mini-DAQ working, and on the next day after the meeting Beni had already his first results. The trigger is generated by the software. There are two codes, one for calculating the pedestals and their widths, which is very fast. The other code analyses the events in the ROC and takes only those channels/events that had signals (within the time window) above a threshold. The statistics you can accumulate will depend on the time it takes to analyze the data in the ROC.

Latest revision as of 23:41, 31 March 2015

January 9, 2014 FDC meeting

Agenda

  1. Installation [1],[2],[3],[4] (all)
  2. Engineering [5], [6], [7] (Bill)
  3. Electronics (Chris, Nick)
  4. Mini-DAQ [8] (Beni)
  5. Other


Minutes

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

Installation

- One quadrant (top, left looking downstream) has been completely cabled at the detector side (see attached pictures), main work done by Mike Klopf (FEL) with the help of Shukui Zhan (FEL) and Lubomir. Now Nick, Robert (FEL) and Shukui are working on the connections at the electronics side. As of today Casey and Tina started cabling the right top side. Cabling procedure: starting with first package per quadrant, each 11 cables are grouped, total of three groups naturally following the pre-amp positions, and bundled together starting at the end of the mesh. In total there are 12 bundles that are then placed on the top cable tray and then the end is re-bundled according to the rack/crate positions.

- In between, while the cables were on the floor, Anatoly tested all the cables at the electronics end with a scope using the translator board which allows to test only the first 8 and the last 8 channels from the 24 in the connector. There were four bad channels (small signals) in packages 3 and 4, most likely conductive tape issues. There's one card with all the channels showing a long shoulder in the signal, we suspect the pre-amp.

- Since Friday last weak we switched the gas from Nitrogen to Ar/CO2 90/10. All the HV channels were OK till Tuesday evening when the same channels (that showed problems before Holidays) starting tripping from time to time. Right now one of the HV channels is really problematic tripping at >1400V (1600V is the nominal). Another four channels are tripping once per 8-24 hours. Certainly the trips are related to the gas. On Monday we expect to get the nominal gas mixture, 40/60.

Engineering

- Bill showed drawings (attached above) with the CDC bearings and attachment that require some space in between the two halves of the mesh. We wanted to put there three HV cables and a ground cable. Bill will get samples of these cable and look in place if they will fit there.

- Bill is trying to figure out the problem with the mass flow controller and contacted the Brooks company. The flow is about a factor of 2 lower than the nominal, but we are not sure how reliable the flow controller is.

- No results yet from the last survey done first week of December.

- Cathode scan: Bill will contact the company, expect a resolution of 100 microns which should be good enough because of the many measurements. Assumption is it will cost about few $k, Eugene agreed. The idea is to fit the scan results with a model with some free parameters that Simon will include in his alignment procedure.

Electronics

- Fernando, Bill, Nick and Chris discussed how to do the "HV return" connection to ground (one per HV connector): will be connected to the ground plate (see Bill's pictures above). There will be also one ground cable connected to one of the two ground plates. The "HV shield" (one per HV connector) should be connected to one shield cable coming from a wire frame. All the other shield (green) cables that are not used (10 per package) should be insulated.

Mini-DAQ

- At the meeting Beni explained he's very close to get the mini-DAQ working, and on the next day after the meeting Beni had already his first results. The trigger is generated by the software. There are two codes, one for calculating the pedestals and their widths, which is very fast. The other code analyses the events in the ROC and takes only those channels/events that had signals (within the time window) above a threshold. The statistics you can accumulate will depend on the time it takes to analyze the data in the ROC.

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