Difference between revisions of "Minutes-8-21-2014"

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= Agenda =
 
= Agenda =
 
# DAQ  (Beni)
 
# DAQ  (Beni)
# CDC status (Mike, Beni)
+
# CDC status [https://logbooks.jlab.org/entry/3291616 Curved Tracks] (Mike, Beni)
# FDC status (Lubomir)
+
# FDC status [http://www.jlab.org/Hall-D/detector/fdc/DAQ/run126_ext1_ev2673_2.pdf scattering event], [http://www.jlab.org/Hall-D/detector/fdc/DAQ/run127_ext2_ev3355_2.pdf horizontal shower event] (Lubomir)
 
# Electronics (Chris, Nick)
 
# Electronics (Chris, Nick)
 
# Engineering (Bill)
 
# Engineering (Bill)
 
#* Chiller
 
#* Chiller
 
#* Cathode scan (Luke)
 
#* Cathode scan (Luke)
# Commissioning [https://hdops.jlab.org/wiki/index.php/Hall_D_Commissioning Wiki Page], [[CDC_commissioning_plan|CDC]], [http://www.jlab.org/Hall-D/detector/fdc/commissioning/ComPlan.pdf FDC commissioning plan] (all)
+
# Commissioning [https://halldweb.jlab.org/hdops/wiki/index.php/Hall_D_Commissioning Wiki Page], [[CDC_commissioning_plan|CDC]], [http://www.jlab.org/Hall-D/detector/fdc/commissioning/ComPlan.pdf FDC commissioning plan] (all)
 
# 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
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== DAQ ==
 
== DAQ ==
  
- Beni: testing the latest fADC125 firmware released, works except something goes wrong in the FPGA when setting event number. ROCFDC3 has problems will be excluded for the next run. We want to take data with the magnet on. The top scintillator paddle was moved as high as possible to reduce the filed on the PMTs. Actually, after the meeting Beni and Elton were able to get signals from the scintillator (after increasing the HV) and started the DAQ (FDC+CDC) with the considence trigger.
+
- Beni: testing the latest fADC125 firmware released, works except something goes wrong in the FPGA when setting event number. ROCFDC3 has problems will be excluded for the next run. We want to take data with the magnet on. The top scintillator paddle was moved as high as possible to reduce the filed on the PMTs. Actually, after the meeting Beni and Elton were able to get signals from the scintillator (after increasing the HV) and started the DAQ (FDC+CDC) with the coincidence trigger.
  
- Discussions about horizontal trigger. We need to install it back. The upstream paddles can be installed when the traget is out. Instead of the downstream paddles one can use the TOF, but it requires the GTP.   
+
- Discussions about horizontal trigger. We need to install it back. The upstream paddles can be installed when the target is out. Instead of the downstream paddles one can use the TOF, but it requires the GTP.   
  
 
== CDC update ==
 
== CDC update ==
  
- Mike:
+
- Mike showed curved tracks (linked) in the CDC at 600A magnetic field. Some local curvatures seen can be explained if the drift time is taken into account.
  
<!--
+
- Fernado: additional ground on the CDC aluminum ring to which the HV is connected has been installed. Expect to reduce the noise significantly. Grounding the HVBs directly will be done as a last resort and it will be done in a different way through the grounding lugs.
== DAQ ==
+
 
+
- Beni: problems running DAQ last night: one of the TI was replaced and had older firmware version. After the meeting Beni found the trigger didn't work due to the magnetic field effect (the magnet is set now to 800A!) on the trigger PMTs: need to be shielded!
+
  
 
== FDC update ==
 
== FDC update ==
  
- Without the horizontal track trigger, the quality of the data is poor: mostly showers and mostly in the first package. To separate hits from noise Lubomir is improving the avalanche finding algorithm using the multi-hit feature of the TDCs and the timing from Curtis, Naomi(CMU), Sean (NU), Beni, Mike, Luke, Eugene, Chris, Nick, Dave, Bill, Fernando, Sergey, Vlad and Lubomir (JLab).
+
- Lubomir: by applying timing cuts on the hits from the two cathodes and the wires in a cell, one can reduce the threshold down to 50 fADC units (~4mV). As a result we see now most of the "missing" cathode channels, that have problems with the conductive tape. Of course the resolution will be deteriorated but one can still use this information for the pattern recognition. Couple of interesting events are linked above.
the fADCs. Last week Cody replaced 4 fADC125 modules due to different issues. In the last short run (the only so far after the FDC chiller was fixed) only one of the new modules works fine, the other three have problems.
+
  
== Electronics ==
 
 
- Fernando: Cody is releasing a new version of the fADC125 firmware with the pulser, masking and playback features. The implementation of the fADC250 algorithms will be ready by the end of August, then in September Cody and Bryan will start testing it.
 
 
 
== Engineering ==
 
== Engineering ==
  
- Bill: the compressor was replaced last Friday but the water flow trough the chiller is very low: the thermostatic valve doesn't open completely. Talking to the company, the most likely reason for that is the low temperature of the chill water of 7-8C. According to their specifications should be above 10C, but before they said it should work also with 8C. Bill's plan is to use an available heat exchanger (from the target) and to warm the input water using the heat of the output water.  
+
- Bill: problems with the chiller on Monday, it was not regulating the temperature. Tom adjusted the thermostatic valve and it started regulating again. Bill discussed with the company the chiller problems. They say the thermostatic valve must be OK, but the new compressor installed is not quite the same as the original one. They don't have spare units and they don't make visits to fix the chiller. If the problems continue, either we have to swap the compressor, or send the chiller to Indiana for repair, or get a new one from Japan. The plan for now is to install the heat exchanger (maybe tomorrow) and continue monitoring.
  
- Bill tested the hard-piping for the chiller that was installed recently (bypassed now). It has water filter for the Fluorinert.
+
- On Monday when the chiller failed, Wesley Moore was working on the epics communication with the device. According to Hovanes he changed the set temperature to a lower value for as short time, then the chiller failed. The plan is just to read the epics variables, and not to write anything to the device.
  
- Luke showed results (linked above) with already 5 measurements across the strips. One sees an irregularity: a big peak and right next to it a dip, but this is exactly at the place where the cathode was hit when it was stored in the counting house. Measurements at the other side of the cathode is not possible (microscope doesn't reach it), unless we rotate the cathode by 180deg. Luke is analyzing now the MCC data.
+
- Luke: we installed the encoder and started measurements at the last position, but in the middle the encoder stopped working. In addition motor got disconnected from the stage. After the meeting the motor was fixed but there were still problems with the encoder. Luke will continue with measurements at two positions. The data with the encoder is enough to compare the two measurement methods.
  
 
== Commissioning ==
 
== Commissioning ==
  
- We discussed briefly what is the trigger we want to use with the target placed ~4m upstream. In this case the BCAL geometrical acceptance is reduced significantly: ~7-14deg compared to >10deg for the nominal target position. Therefore, including the BCAL in the trigger will select mostly events originating from the nominal target. Curtis: the pions are mostly in the forward direction and this may not be an issue. In any case we need simulations and Simon already started doing them.
+
- Curtis presented a plan for the CDC commissioning linked above. When aligning the photon beam several inner HVBs will be supplied by Bertan modules so that one can see the currents which may help in the beam alignment. Then the plan is to have some initial data with magnet on for a short time, then for a longer time with the magnet off, and then with the magnet on again. They are concerned that the timing algorithm on the fADC125 may not be ready for the run. Eugene: while working on the photon beam the magnet will stay at 300A which is safe; this time can be used for the initial data collection.
 
+
-Curtis: According to Eugene, there will probably be minimal choice in the trigger. At best, we will be able
+
to control the relative fraction of BCAL and FCAl energy.
+
  
- Everybody agrees we better align the chambers without any magnetic field. If the trigger rate is too high an option will be to mask the inner FCAL blocks.
+
- As Bill proposed on the last meeting it will be good to survey the FDC without magnetic field (planned already for September) and then to monitor one of the reflector while the magnet goes up. Eugene: the best would be to rump up the magnet when the Hall is opened in September and at the same time the survey can be done.
  
- Bill proposed to survey the FDC (the 16 reflectors visible from downstream) next week when the magnet will be set to 1200A.
+
== Other ==
  
-->
+
- Beni: Scot put alcohol in the bubblers, we will monitor the chamber behavior.

Latest revision as of 03:23, 1 April 2015

August 21, 2014 FDC+CDC meeting

Agenda

  1. DAQ (Beni)
  2. CDC status Curved Tracks (Mike, Beni)
  3. FDC status scattering event, horizontal shower event (Lubomir)
  4. Electronics (Chris, Nick)
  5. Engineering (Bill)
    • Chiller
    • Cathode scan (Luke)
  6. Commissioning Wiki Page, CDC, FDC commissioning plan (all)
  7. Other

Instructions for Bluejeans meeting connection

FDC meeting ID: 290664653

Minutes

Participants: Curtis, Naomi (CMU), Sean (NU), Beni, Mike, Luke, Eugene, Chris, Nick, Dave, Bill, Fernando, Sergey, Vlad and Lubomir (JLab).

DAQ

- Beni: testing the latest fADC125 firmware released, works except something goes wrong in the FPGA when setting event number. ROCFDC3 has problems will be excluded for the next run. We want to take data with the magnet on. The top scintillator paddle was moved as high as possible to reduce the filed on the PMTs. Actually, after the meeting Beni and Elton were able to get signals from the scintillator (after increasing the HV) and started the DAQ (FDC+CDC) with the coincidence trigger.

- Discussions about horizontal trigger. We need to install it back. The upstream paddles can be installed when the target is out. Instead of the downstream paddles one can use the TOF, but it requires the GTP.

CDC update

- Mike showed curved tracks (linked) in the CDC at 600A magnetic field. Some local curvatures seen can be explained if the drift time is taken into account.

- Fernado: additional ground on the CDC aluminum ring to which the HV is connected has been installed. Expect to reduce the noise significantly. Grounding the HVBs directly will be done as a last resort and it will be done in a different way through the grounding lugs.

FDC update

- Lubomir: by applying timing cuts on the hits from the two cathodes and the wires in a cell, one can reduce the threshold down to 50 fADC units (~4mV). As a result we see now most of the "missing" cathode channels, that have problems with the conductive tape. Of course the resolution will be deteriorated but one can still use this information for the pattern recognition. Couple of interesting events are linked above.

Engineering

- Bill: problems with the chiller on Monday, it was not regulating the temperature. Tom adjusted the thermostatic valve and it started regulating again. Bill discussed with the company the chiller problems. They say the thermostatic valve must be OK, but the new compressor installed is not quite the same as the original one. They don't have spare units and they don't make visits to fix the chiller. If the problems continue, either we have to swap the compressor, or send the chiller to Indiana for repair, or get a new one from Japan. The plan for now is to install the heat exchanger (maybe tomorrow) and continue monitoring.

- On Monday when the chiller failed, Wesley Moore was working on the epics communication with the device. According to Hovanes he changed the set temperature to a lower value for as short time, then the chiller failed. The plan is just to read the epics variables, and not to write anything to the device.

- Luke: we installed the encoder and started measurements at the last position, but in the middle the encoder stopped working. In addition motor got disconnected from the stage. After the meeting the motor was fixed but there were still problems with the encoder. Luke will continue with measurements at two positions. The data with the encoder is enough to compare the two measurement methods.

Commissioning

- Curtis presented a plan for the CDC commissioning linked above. When aligning the photon beam several inner HVBs will be supplied by Bertan modules so that one can see the currents which may help in the beam alignment. Then the plan is to have some initial data with magnet on for a short time, then for a longer time with the magnet off, and then with the magnet on again. They are concerned that the timing algorithm on the fADC125 may not be ready for the run. Eugene: while working on the photon beam the magnet will stay at 300A which is safe; this time can be used for the initial data collection.

- As Bill proposed on the last meeting it will be good to survey the FDC without magnetic field (planned already for September) and then to monitor one of the reflector while the magnet goes up. Eugene: the best would be to rump up the magnet when the Hall is opened in September and at the same time the survey can be done.

Other

- Beni: Scot put alcohol in the bubblers, we will monitor the chamber behavior.