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

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# Electronics (Chris, Nick)
 
# Electronics (Chris, Nick)
 
# Other
 
# Other
 
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= Minutes =
 
= Minutes =
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- 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.  
 
- 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.
 
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== 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 (to make space for the CDC) without releasing the cables. 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).
 
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- 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.
+
  
- 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.
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== Electronics ==
 
== Electronics ==

Revision as of 18:44, 17 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 (to make space for the CDC) without releasing the cables. 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).