Difference between revisions of "Minutes-6-5-2014"

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= Agenda =
 
= Agenda =
−
# Gas system [http://www.jlab.org/Hall-D/detector/fdc/gas_system/Tank_p_2014-06-02at1.19.01PM.png], [http://www.jlab.org/Hall-D/detector/fdc/gas_system/Tank_p_2014-06-02at4.36.31PM.png], [http://www.jlab.org/Hall-D/detector/fdc/gas_system/Tank_p_2014-06-02at4.38.23PM.png], [http://www.jlab.org/Hall-D/detector/fdc/gas_system/Tank_p_2014-06-03at9.00.41AM.png], [http://www.jlab.org/Hall-D/detector/fdc/gas_system/Tank_p_2014-06-04at11.09.50AM.png]
+
# Gas system [http://www.jlab.org/Hall-D/detector/fdc/gas_system/Tank_p_2014-06-02at1.19.01PM.png], [http://www.jlab.org/Hall-D/detector/fdc/gas_system/Tank_p_2014-06-02at4.36.31PM.png], [http://www.jlab.org/Hall-D/detector/fdc/gas_system/Tank_p_2014-06-02at4.38.23PM.png], [http://www.jlab.org/Hall-D/detector/fdc/gas_system/Tank_p_2014-06-03at9.00.41AM.png], [http://www.jlab.org/Hall-D/detector/fdc/gas_system/Tank_p_2014-06-04at11.09.50AM.png], [http://www.jlab.org/Hall-D/detector/fdc/gas_system/GAS_GUI.png Mike's gas GUI]
 
# DAQ (Beni)
 
# DAQ (Beni)
 
# CDC status (Mike)
 
# CDC status (Mike)
 
# Engineering (Bill)
 
# Engineering (Bill)
−
#* cathode measurements
+
#* cathode measurements [http://www.jlab.org/Hall-D/detector/fdc/calibration/CScan_microscop1.JPG]
 
# Electronics (Chris, Nick)
 
# Electronics (Chris, Nick)
 
# Instructions for shift workers (Beni, Lubomir)
 
# Instructions for shift workers (Beni, Lubomir)
−
#* [https://hdops.jlab.org/wiki/index.php/Main_Page Wiki Page]
+
#* [https://halldweb.jlab.org/hdops/wiki/index.php/Main_Page Wiki Page]
 
# FDC alignment  [http://www.jlab.org/Hall-D/detector/fdc/calibration/FDCresolution.pdf] (Lubomir)
 
# FDC alignment  [http://www.jlab.org/Hall-D/detector/fdc/calibration/FDCresolution.pdf] (Lubomir)
−
# FDC pedestal resolution: [[media:pedestal_resolution.pdf]]
+
# FDC pedestal resolution: [[media:pedestal_resolution.pdf]] (Beni)
 
# Other
 
# Other
  
−
[https://halldweb1.jlab.org/wiki/index.php/Connect_to_Bluejeans_Meetings Instructions for Bluejeans meeting connection]
+
[https://halldweb.jlab.org/wiki/index.php/Connect_to_Bluejeans_Meetings Instructions for Bluejeans meeting connection]
  
 
FDC meeting ID: 290664653
 
FDC meeting ID: 290664653
−
 
−
<!--
 
  
 
= Minutes =
 
= Minutes =
  
−
Participants: Curtis, Naomi (CMU), Eugene, Bill, Dave, Chris, Nick, Simon, Fernando, Mike, and Lubomir (JLab).
+
Participants: Curtis (CMU), Bill, Beni, Chris, Nick, Simon, Fernando, and Lubomir (JLab).
  
 
== Gas system ==
 
== Gas system ==
  
−
- Both CDC and FDC are now connected to the gas system. Some minor issues (like tube/cable swapping, gas settings) were resolved. FDC bubbles at 50 sccpm per package but now we are flushing it with 100 sccpm (nominal is 200 sccpm per package). CDC is being flushed with 1l/m (nominal 3l/m). From the gas GUI for experts (attached) we see the pressures in the individual cells within a FDC package are very similar. Bill is surprised and requested testing at different scanning times. When all the solenoid valves are closed the pressure sensor reads high pressure that increases; could be explained by heat flow.  
+
- There were several problems in the FDC parts of the gas system. A series of graphs (from Mike) linked above demonstrate some of them. A 1 l/min leak was found due to bad fitting of one of the valves and later fixed: first graph shows the pressure in the mixing tank (red is FDC) with ~2 l/min filling flow and 0.4l/m FDC usage. To identify the place we were excluding different parts of the system. Once the tank was insulated (flat part in second graph) there was still some pressure drop; it turned out there's a small leak from the relief valve on top of the FDC mixing tank. Same valve is used on the CDC tank but it has not been checked. Narciso is looking for better valves.  
  
−
- We were having problems with the gas control panel for the FDC: the display would disappear and then it requires turning off/on the power several times to reappear and some of the settings may be wrong. We are also not sure if it is only display problem or also the gas flow is disrupted. Maybe related to that: we need to fill the mixing tank with a flow that is a factor of 2 bigger than what is expected from the FDC usage. We need a spare control panel (Eugene requested a price estimate).  
+
- On Tuesday ~6pm there was again a failure of the FDC gas control box in the gas room. As a result the pressure in the mixing tank started dropping below 7 psi. We had to call the guard to open the room and reset the box. A new spare box has been ordered. For the future Beni suggests to have a key from the gas room in the counting house.
  
−
- It turned out the FDC part, including the mixing tank, were flushed over the weekend with 60/40 Ar/CO2 gas mixture, instead of 40/60. On Tuesday/Wednesday the detector was also flushed with the wrong gas mixture and as a result there were HV trips at that time.  
+
- Pressures in the six cells of package 1 are shown in third and fourth graph, when the flow was turned off and then on. It shows very small (~1Pa) variations probably due to temperature and very similar values in the different cells.
−
+
−
== CDC status == 
+
  
−
- Mike: still can't have all the HV channels working: the problems is in the CAEN modules. Will use one 1535P module instead of 1550P but that is not enough. Mike will do another CDC leakage test. The temperatures at the pre-amps are oscillating by 1-1.5 deg; still using the same cooling.    
+
- Mike has his first version of the gas GUI ready (screenshot linked above) and checked in the svn: https://halldsvn.jlab.org/repos/trunk/controls/css. Any remarks and recommendations are welcome and should be directed to Mike.
  
−
== Electronics ==
+
== DAQ and CDC status ==  
  
−
- Fernando: will discuss the HV issues with the CAEN people and request additional checks. Two HV modules are being repaired now, three were repaired before, all having problems with setting/holding HV. In addition we have many channels showing dark current of 0.5-1 uA without anything connected to the module. Eugene wanted to know how many spare modules we will need.
+
- No news here. DAQ is in the Sasha's hands now.
  
 
== Engineering ==
 
== Engineering ==
  
−
- We discussed once more if we want to scan the spare cathode with the JLab CMM machine; Eugene is reluctant since it requires (Bill) special stiff arm to hold the camera. Instead Eugene suggested to do measurements with a special ruler/scale (Fernando has it) only at the places where we suspect the original scan had problems.  
+
- We have a plan to use Fernando's glass scale to do measurements on the cathode. It has to be read out with a microscope with a reticle: see picture done with a cell phone on the top of the eyepiece of the microscope. We can mount a web camera on the eyepiece that has a reticle, or use the built-in microscope camera if it has a software that allows measurements (Bill will check with Chris and Nick about that).
  
−
- The chiller was put on scale and will check the weight in a month to estimate the Fluorinert leakage. Casey got the parts to make the extension for the sniffer to look for the leakage.
+
== Electronics ==
 +
 
 +
- Fernando discussed the HV issue with CAEN. They say they have higher failure rate for 1550P modules of 3-5 modules per year (we already sent them 6 of these???). In the moment 4 modules are being repaired by CAEN and the turnaround time might be long (2 were sent already beginning of May). Fernando recommended to order 2 spare 1550P modules (each ~$7k). We don't need more spares for 1550N used in the FDC only; we have one spare and 4 in use.  
 +
 
 +
== Instructions for shift workers ==
 +
 
 +
- For the Hall D readiness review Beni and Lubomir prepared instructions for the shift takers for the CDC,FDC and the Gas System. Look at the link above and give recommendations/corrections to Beni and Lubomir.
  
 
== FDC alignment ==
 
== FDC alignment ==
  
−
- Lubomir showed results (linked above) about the FDC resolutions. Applying the offsets and rotations shown in the table, the cosmic tracks were reconstructed using cells #1,2, and 4, and the resolutions in x (from wires) and in y (from strips) for cell #3 were estimated. The wire resolution over the whole cell is ~150 microns in the 1-4mm region, which is a "record-high" resolution for the FDC and a result of the precise alignment. The strip resolution is 220 microns while we expect it to be ~150-200 microns, which means better strip alignment is needed.
+
- Lubomir updated the alignment document, still far from final.
 +
 
 +
== FDC pedestal resolution ==
  
−
-->
+
- Beni demonstrated with the attached plot that the pedestal resolution is improved when you average over more samples. Certainly 6 samples (as it is now) are not enough and we better have 20 or more if the firmware allows it.

Latest revision as of 06:05, 1 April 2015

June 5, 2014 FDC+CDC meeting

Agenda

  1. Gas system [1], [2], [3], [4], [5], Mike's gas GUI
  2. DAQ (Beni)
  3. CDC status (Mike)
  4. Engineering (Bill)
    • cathode measurements [6]
  5. Electronics (Chris, Nick)
  6. Instructions for shift workers (Beni, Lubomir)
  7. FDC alignment [7] (Lubomir)
  8. FDC pedestal resolution: media:pedestal_resolution.pdf (Beni)
  9. Other

Instructions for Bluejeans meeting connection

FDC meeting ID: 290664653

Minutes

Participants: Curtis (CMU), Bill, Beni, Chris, Nick, Simon, Fernando, and Lubomir (JLab).

Gas system

- There were several problems in the FDC parts of the gas system. A series of graphs (from Mike) linked above demonstrate some of them. A 1 l/min leak was found due to bad fitting of one of the valves and later fixed: first graph shows the pressure in the mixing tank (red is FDC) with ~2 l/min filling flow and 0.4l/m FDC usage. To identify the place we were excluding different parts of the system. Once the tank was insulated (flat part in second graph) there was still some pressure drop; it turned out there's a small leak from the relief valve on top of the FDC mixing tank. Same valve is used on the CDC tank but it has not been checked. Narciso is looking for better valves.

- On Tuesday ~6pm there was again a failure of the FDC gas control box in the gas room. As a result the pressure in the mixing tank started dropping below 7 psi. We had to call the guard to open the room and reset the box. A new spare box has been ordered. For the future Beni suggests to have a key from the gas room in the counting house.

- Pressures in the six cells of package 1 are shown in third and fourth graph, when the flow was turned off and then on. It shows very small (~1Pa) variations probably due to temperature and very similar values in the different cells.

- Mike has his first version of the gas GUI ready (screenshot linked above) and checked in the svn: https://halldsvn.jlab.org/repos/trunk/controls/css. Any remarks and recommendations are welcome and should be directed to Mike.

DAQ and CDC status

- No news here. DAQ is in the Sasha's hands now.

Engineering

- We have a plan to use Fernando's glass scale to do measurements on the cathode. It has to be read out with a microscope with a reticle: see picture done with a cell phone on the top of the eyepiece of the microscope. We can mount a web camera on the eyepiece that has a reticle, or use the built-in microscope camera if it has a software that allows measurements (Bill will check with Chris and Nick about that).

Electronics

- Fernando discussed the HV issue with CAEN. They say they have higher failure rate for 1550P modules of 3-5 modules per year (we already sent them 6 of these???). In the moment 4 modules are being repaired by CAEN and the turnaround time might be long (2 were sent already beginning of May). Fernando recommended to order 2 spare 1550P modules (each ~$7k). We don't need more spares for 1550N used in the FDC only; we have one spare and 4 in use.

Instructions for shift workers

- For the Hall D readiness review Beni and Lubomir prepared instructions for the shift takers for the CDC,FDC and the Gas System. Look at the link above and give recommendations/corrections to Beni and Lubomir.

FDC alignment

- Lubomir updated the alignment document, still far from final.

FDC pedestal resolution

- Beni demonstrated with the attached plot that the pedestal resolution is improved when you average over more samples. Certainly 6 samples (as it is now) are not enough and we better have 20 or more if the firmware allows it.

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