Difference between revisions of "Minutes-2-12-2015"

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#* efficiency studies [http://www.jlab.org/Hall-D/detector/fdc/commissioning/FDC3_eff_thr50.pdf],[http://www.jlab.org/Hall-D/detector/fdc/commissioning/FDC3_eff_thr100.pdf],[http://www.jlab.org/Hall-D/detector/fdc/commissioning/FDC3_eff_thr150.pdf],[http://www.jlab.org/Hall-D/detector/fdc/commissioning/FDC3_eff_thr200.pdf],[http://www.jlab.org/Hall-D/detector/fdc/commissioning/FDC3_eff_proj.pdf],   
 
#* efficiency studies [http://www.jlab.org/Hall-D/detector/fdc/commissioning/FDC3_eff_thr50.pdf],[http://www.jlab.org/Hall-D/detector/fdc/commissioning/FDC3_eff_thr100.pdf],[http://www.jlab.org/Hall-D/detector/fdc/commissioning/FDC3_eff_thr150.pdf],[http://www.jlab.org/Hall-D/detector/fdc/commissioning/FDC3_eff_thr200.pdf],[http://www.jlab.org/Hall-D/detector/fdc/commissioning/FDC3_eff_proj.pdf],   
 
# Other
 
# Other
 
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= Minutes =
 
= Minutes =
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-  Cody: testing the f125 with the latest firmware at high rates in block-mode. In mode 8 one can reach 5kHz, in mode 1 up to 20kHz, and in mode 7 up to 50kHz -  these limits correspond to 100% occupancy.  
 
-  Cody: testing the f125 with the latest firmware at high rates in block-mode. In mode 8 one can reach 5kHz, in mode 1 up to 20kHz, and in mode 7 up to 50kHz -  these limits correspond to 100% occupancy.  
 +
 +
== Engineering ==
 +
 +
- Dave: CDC flow sensor is ready.
  
 
== CDC update ==
 
== CDC update ==
  
- Mike showed a plot linked above, with the resolutions (sigma of the residuals) vs drift time. The residuals were obtained from tracking in magnetic field (somehow the track quality is poorer without field) after Simon applied    
+
- Mike showed a plot linked above, with the resolutions (sigma of the residuals) vs drift time. The residuals were obtained from tracking in magnetic field (somehow the track quality is poorer without field) after Simon's alignment. The resolutions are very good, ~130 microns for >100ns. The poor resolution for <100ns can be explained by poor timing resolution.    
 +
 
 +
<!--
  
 
== FDC update ==
 
== FDC update ==
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== Electronics ==
 
== Electronics ==
 
- Out of 8 channels left in the FDC that have problems outside of the detector, Nick found 5 with problems in the 3M connectors. These have been fixed but not tested yet.
 
-->
 

Revision as of 18:07, 13 February 2015

February 12, 2015 FDC+CDC meeting

Connection

  1. Instructions for Bluejeans meeting connection
  2. FDC meeting ID: 290664653
  3. To join via a Web Browser, go to the page [1] https://bluejeans.com/290664653.

Agenda

  1. Gas issues
  2. Electronics (Fernando, Cody)
  3. Engineering (Dave)
  4. CDC update Resolution Vs. Drift time 1200A(Mike)
  5. FDC update (Lubomir)
  6. Other

Minutes

Participants: Naomi (CMU) Eugene, Tim, Dave, Fernando, Mike, Chris, Nick, Simon, Beni, and Lubomir (JLab).

Gas issues

- We had very long discussions what to do with the CDC leakage. Everybody agrees that CDC can't be operated like this and the leak has to be fixed. Different proposals: start removing the HVB cards and check with the sniffer the holes at the cheese plate (Beni, Nick, Fernando), check for leaks at the downstream mylar window with a tube on the sniffer (Dave), take some cosmic data overnight, if the leak is at the cheese plate the straws will still have some gas flow and the data should be OK (Lubomir).

- By the time I'm writing the minutes, Nick removed all the cables at the front and a portion of the HVB cards at the bottom. Thus, Mike and Nick were able to sniff the entire cheese plate without finding anything localized. The place with the maximum beeping is at the bottom, between BCAL and CDC, but the gas is heavier than air so it may come from anywhere. On Friday afternoon Tim and Eugene decided to pull the CDC out of the bore. Target people are preparing the target. On Monday morning it will be craned to the floor and the CDC will be pulled out.

- The CO2 sensor came back from repair. We calibrated it with 60/40 CO2/Ar certified mixture in the EEL126, and then started monitoring the CO2 in the first FDC package. Results are linked: some variations for 20 hours, maybe related to the gas temperature, has to be monitored for longer time.

Electronics

- Fernando: the higher CDC noise (~60mV compared to ~30mV before) related to the loop on HV cables we had before that acts as an inductance. Fernando tested the new HV filter from CAEN on one cable and it worked great: noise <20mV (with or without loop). This was only a prototype box, now we need 13 more to put on all the cables. Fernando agreed that if we remove the CDC, the HV cables can be re-routed with a loop.

- Cody: testing the f125 with the latest firmware at high rates in block-mode. In mode 8 one can reach 5kHz, in mode 1 up to 20kHz, and in mode 7 up to 50kHz - these limits correspond to 100% occupancy.

Engineering

- Dave: CDC flow sensor is ready.

CDC update

- Mike showed a plot linked above, with the resolutions (sigma of the residuals) vs drift time. The residuals were obtained from tracking in magnetic field (somehow the track quality is poorer without field) after Simon's alignment. The resolutions are very good, ~130 microns for >100ns. The poor resolution for <100ns can be explained by poor timing resolution.