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

From GlueXWiki
Jump to: navigation, search
Line 24: Line 24:
 
== Engineering ==   
 
== 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).
+
- 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.
  
== Electronics ==
+
- 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.
  
- 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.
+
- 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.
 
+
- 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.
+
== Electronics ==
 
+
== Other ==
+
 
+
- For the next three weeks Beni will be chairing the meetings; Lubomir is in vacation.
+
  
-->
+
== CDC update ==

Revision as of 10:31, 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

CDC update