Difference between revisions of "Minutes-4-17-2014"

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## Beni's results with DAQ
 
## Beni's results with DAQ
 
# Engineering (Bill, Dave)
 
# Engineering (Bill, Dave)
−
## Gas system status [http://www.jlab.org/Hall-D/detector/fdc/gas_system/GAS_SYSTEM_PI_DIAGRAM_PRELIM.pdf] [http://www.jlab.org/Hall-D/detector/fdc/gas_system/FDC_Gas_Panel_Op_4_15.docx]
+
## Gas system status [http://www.jlab.org/Hall-D/detector/fdc/gas_system/GAS_SYSTEM_PI_DIAGRAM_PRELIM.pdf],[http://www.jlab.org/Hall-D/detector/fdc/gas_system/FDC_Gas_Panel_Op_4_15.docx]
 +
## Experimental Safety Assessment Document [http://www.jlab.org/Hall-D/detector/fdc/documents/HallD_ESAD.pdf HallD_ESAD]
 
## Other
 
## Other
 
# Electronics (Chris, Nick)
 
# Electronics (Chris, Nick)
 
# Other
 
# Other
−
 
−
<!--
 
  
 
= Minutes =
 
= Minutes =
  
−
Participants: Eugene, Fernando, Bill, Chris, Nick, Simon, Beni, and Lubomir.
+
Participants: Eugene, Fernando, Dave, Nick, Simon, and Lubomir.
  
−
== Final installation and testing ==
+
== FDC testing status ==
  
−
- FDC was inserted last Thursday. This time we used a cable support attached to the side rails with bearings. After insertion, connecting of the cooling system and turning on the LV we found one LV cable was disconnected in the third package. We borrowed a fancy HD videoscope from SRF and were able to look from the downstream side: probably one wire got caught on something and one side of the LV connector was disconnected. Bill and Dave prepared different tools (pictures attached) and on Monday we tried to insert the connector back but it didn't work. In the meantime we found 7 wire channels disconnected: later it turned out the signal cable was pulled and the connector was partially out.
+
- Final results from the scope test (done by Anatoly) of all the channels with FDC in its final position are in the spreadsheet linked above. About 50 strip channels (0.4% of all the strips) are identified as having some kind of problem, almost all of them related to the conductive tape issue. As compared to the scope tests done after the first "final" insertion almost nothing changed, i.e. the re-insertion didn't create additional problems.  
−
 
+
−
- On Tuesday we took the FDC back on the platform. Casey fixed the LV connector; he had to fix also two pins on the daughter card connector that were bent. The wire channels and several cathode channels were also fixed. For 30 min. the TDCs were tested with DAQ and then FDC was inserted back (all done before noon). During the operation we kept the cooling connected and were monitoring the LV currents.
+
−
 
+
−
- After the first insertion Anatoly tested all the cathode channels with scope: about 50 bad channels to be compared to 18 before the insertion. After the re-insertion on Tuesday till now, Anatoly has tested half of the crates (we assumed Beni will be able to test the rest with DAQ) and there were no surprises. Anatoly will continue and test all the cathode channels. All of the bad channels (with few possible exceptions) are in the third and fourth package, where we didn't use the vacuum fixture for the cathodes. Eugene suggested to have a special session to discuss the lessons learned from the FDC production and installation. 
+
−
 
+
−
- Beni and Cody made significant progress in reading the fADC125. After re-arranging the modules they were able to read half of the crates. Then Cody changed the VME clock from 80MHz to 40MHz and they were able to read the other half of the crates, as well. Still the results coming from the DAQ are with low statistics. They are enough to see that there are no significant problems (like bad connector) but most of the channels have few events and some have zeroes, so one can't count how many are the bad channels. Many of the channels on the most upstream cell (next to the mesh) have noise (up to 20kHz) that results in big output files. Beni will implement individual thresholds for all the channels to suppress the noisy channels.
+
−
 
+
−
- All the wire channels are working fine as tested with the DAQ. From time to time there's noise (up to few kHz) on some channels, again in the first package.
+
  
 +
- Comparing with the Beni's DAQ results: all the problematic channels from the scope test can be identified in the Beni's histograms as deviating from the neighboring channels, except several channels that are probably dominated by a noise. In addition to the 50 bad channels from the scope test, there are about 30 new bad channels in the Beni's results. Lubomir looked with a scope into 10 of these channels and didn't find any problem. Fernando and Chris did similar test with a scope and concluded for most of the channels the signals at the input of the fADCs are good. However, according the Beni the problematic channels move with the cable. Therefore Fernando suspects it might be the front panel on the fADC that prevents the cable connector from completely going in the fADC connector. They will investigate this.
 +
 
== Engineering ==   
 
== Engineering ==   
  
−
- The FDC was put in its final position based on marks on the rails. After the survey we may not need to move the FDC if it is within 2-3 mm from the nominal (Eugene). The most important is to install the stops before the survey to make sure FDC doesn't move and we know its position.
+
- Last week the FDC was moved downstream by about 5mm (info from Josh) to make space for the CDC, without releasing the FDC cables on the face of the magnet. According to Casey they just looked to make sure there's no tension on the cables. Then stoppers were installed on both FDC and CDC side on the rail. On Tuesday survey of the FDC in its final position was done. Important is that they were able to see all the 16 reflectors installed on the periphery of the packages. Before that the CDC was surveyed: it is off by 7mm downstream with respect to the nominal position (Eugene).
  
−
- Dave and Bill put a lot of efforts on Monday to make fixing tools. For the future, different ideas wre discussed. Bill: the simplest thing would be to have a spring that is compressed when inserted and then released. Bill could not find a telescopic mechanism with such sizes, but such tool can be made.
+
- The gas system is next on the list, the OSP for the pressure testing will be signed soon and beginning of next week the test will be done. Dave is working on the procedure (files attached) for testing and flushing the whole gas system which is suppose to happen by the end of next week. Yesterday the mass flow controller that was used temporary for the FDC was needed to complete the gas system and was replaced with a rotameter that somehow consumes much more gas. Fernando: flushing with alcohol will require also OSP. That's why the flushing will be done for now without alcohol, later it will be added.  
  
−
- Again we had long discussions about the cathode scan and possible systematic errors in the measurements. The reason for the jump of 250 microns in the middle is still unknown. People from Hexagon confirmed it is possible to have deviations after re-homing of the device, but not so big (Bill). We discussed if we want to scan another cathode. Eugene prefers to use different method, like using simple ruler, to check the scan results. Lubomir will do additional analyses to check the consistency of the measurements.
+
- Elton is working on the ESAD document and we are responsible for the FDC and the gas sections there. The first version is attached above (pages 14-15).
 +
Fernando: the HV and LV hazards will be described in the electronics section, so we just have to refer to that section.  
  
 +
- At the beginning of the week the Fluorinert level was very low and we put the last gallon we had, in the chiller and even after that the level is much below the "low" mark. We suspect some leakage and will need the Fluorinert sniffer again to check at least the outside connections. Dave ordered another container (20kg) with Fluorinert. 
 +
 
== Electronics ==
 
== Electronics ==
  
−
- FDC and the mesh have to be grounded before we can discuss the noise problems. We may need improvement of the ground of the most upstream cell, next to the mesh.
+
- Fernando: the LV supplies are now regulating the sense voltage, i.e. the voltage on the patch panels. The numbering convention for the electronics channels should be followed, i.e. first channels is 0.
−
 
+
−
- A LV cable was cut during installation: the insulation and 3 out of  10 wires were damaged, but there's still LV on the cards. Chris ordered parts needed to fix it. Most likely it was cut on the rail shims; we were sliding the cables on the top of the rails without realizing how sharp the shims are! Fernando suggested inspecting all the cables for such cuts.
+
−
 
+
−
- Several 3M connectors have to be fixed, but we want to make sure they are really bad, because fixing is difficult. One connector can't be disconnected from the module: the plastic part separated from the metal base.  
+
−
+
−
- 12 pre-amps that were replaced on the FDC were given to Nick for evaluation. Not all are necessarily bad, it could be also the connector on the pre-amp/daughter card that after replacement resulted in better connection.
+
  
−
== Other ==
+
- The FDC ground is now connected directly to the clean ground while the CDC ground is not connected. There's no ground connection for the mesh: it might be difficult but not impossible, to connect a ground cable on the side of the mesh. Soon the ground panel on the face of the magnet will be attached to the clean ground and the FDC, CDC, and the mesh grounds will be attached to that panel.
 +
   
 +
== CDC update ==
  
−
- For the next three weeks Beni will be chairing the meetings; Lubomir is in vacation.
+
- Due to the big overlap in equipment, procedures, software (gas system, pre-amps, fADC, HV, LV modules, DAQ, testing software) with the CDC and the experts present at this meeting, Fernando proposed and everybody agreed that this meeting is the right place to give updates also on the CDC activities.
  
−
-->
+
- Nick and two techs finished the connections of the signal cables to the CDC. Now in principle one can apply LV on the pre-amps and Beni can look at the pedestal widths with the mini-DAQ to check the cable connectivity. Before that the cooling needs to be finished and make temperature measurements on the pre-amps. After the test of the gas system, in about 10-14 days, one can start flushing the CDC.

Latest revision as of 11:04, 18 April 2014

April 17, 2014 FDC meeting

Agenda

  1. FDC testing status (Lubomir)
    1. Final scope results
    2. Beni's results with DAQ
  2. Engineering (Bill, Dave)
    1. Gas system status [1],[2]
    2. Experimental Safety Assessment Document HallD_ESAD
    3. Other
  3. Electronics (Chris, Nick)
  4. Other

Minutes

Participants: Eugene, Fernando, Dave, Nick, Simon, and Lubomir.

FDC testing status

- Final results from the scope test (done by Anatoly) of all the channels with FDC in its final position are in the spreadsheet linked above. About 50 strip channels (0.4% of all the strips) are identified as having some kind of problem, almost all of them related to the conductive tape issue. As compared to the scope tests done after the first "final" insertion almost nothing changed, i.e. the re-insertion didn't create additional problems.

- Comparing with the Beni's DAQ results: all the problematic channels from the scope test can be identified in the Beni's histograms as deviating from the neighboring channels, except several channels that are probably dominated by a noise. In addition to the 50 bad channels from the scope test, there are about 30 new bad channels in the Beni's results. Lubomir looked with a scope into 10 of these channels and didn't find any problem. Fernando and Chris did similar test with a scope and concluded for most of the channels the signals at the input of the fADCs are good. However, according the Beni the problematic channels move with the cable. Therefore Fernando suspects it might be the front panel on the fADC that prevents the cable connector from completely going in the fADC connector. They will investigate this.

Engineering

- Last week the FDC was moved downstream by about 5mm (info from Josh) to make space for the CDC, without releasing the FDC cables on the face of the magnet. According to Casey they just looked to make sure there's no tension on the cables. Then stoppers were installed on both FDC and CDC side on the rail. On Tuesday survey of the FDC in its final position was done. Important is that they were able to see all the 16 reflectors installed on the periphery of the packages. Before that the CDC was surveyed: it is off by 7mm downstream with respect to the nominal position (Eugene).

- The gas system is next on the list, the OSP for the pressure testing will be signed soon and beginning of next week the test will be done. Dave is working on the procedure (files attached) for testing and flushing the whole gas system which is suppose to happen by the end of next week. Yesterday the mass flow controller that was used temporary for the FDC was needed to complete the gas system and was replaced with a rotameter that somehow consumes much more gas. Fernando: flushing with alcohol will require also OSP. That's why the flushing will be done for now without alcohol, later it will be added.

- Elton is working on the ESAD document and we are responsible for the FDC and the gas sections there. The first version is attached above (pages 14-15). Fernando: the HV and LV hazards will be described in the electronics section, so we just have to refer to that section.

- At the beginning of the week the Fluorinert level was very low and we put the last gallon we had, in the chiller and even after that the level is much below the "low" mark. We suspect some leakage and will need the Fluorinert sniffer again to check at least the outside connections. Dave ordered another container (20kg) with Fluorinert.

Electronics

- Fernando: the LV supplies are now regulating the sense voltage, i.e. the voltage on the patch panels. The numbering convention for the electronics channels should be followed, i.e. first channels is 0.

- The FDC ground is now connected directly to the clean ground while the CDC ground is not connected. There's no ground connection for the mesh: it might be difficult but not impossible, to connect a ground cable on the side of the mesh. Soon the ground panel on the face of the magnet will be attached to the clean ground and the FDC, CDC, and the mesh grounds will be attached to that panel.

CDC update

- Due to the big overlap in equipment, procedures, software (gas system, pre-amps, fADC, HV, LV modules, DAQ, testing software) with the CDC and the experts present at this meeting, Fernando proposed and everybody agreed that this meeting is the right place to give updates also on the CDC activities.

- Nick and two techs finished the connections of the signal cables to the CDC. Now in principle one can apply LV on the pre-amps and Beni can look at the pedestal widths with the mini-DAQ to check the cable connectivity. Before that the cooling needs to be finished and make temperature measurements on the pre-amps. After the test of the gas system, in about 10-14 days, one can start flushing the CDC.

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