Difference between revisions of "Minutes-7-24-2014"

From GlueXWiki
Jump to: navigation, search
m (Text replacement - "/halldweb1.jlab.org/" to "/halldweb.jlab.org/")
 
(8 intermediate revisions by one other user not shown)
Line 4: Line 4:
 
# DAQ  (Beni)
 
# DAQ  (Beni)
 
# CDC status (Mike, Beni)
 
# CDC status (Mike, Beni)
#* noise studies [http://www.jlab.org/Hall-D/detector/CDC/noise/test4 noise studies]
+
#* [http://www.jlab.org/Hall-D/detector/CDC/noise/test4 noise studies]
 
# FDC status [http://www.jlab.org/Hall-D/detector/fdc/DAQ/First_Track_All_FDC.pdf First Track through all packages] (Lubomir)
 
# FDC status [http://www.jlab.org/Hall-D/detector/fdc/DAQ/First_Track_All_FDC.pdf First Track through all packages] (Lubomir)
 
# Electronics (Chris, Nick)
 
# Electronics (Chris, Nick)
Line 10: Line 10:
 
# 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 =
Line 26: Line 24:
 
== CDC update ==
 
== CDC update ==
  
- Beni studied the noise  
+
- Beni studied the CDC noise once again (all the results are linked above): using a scope on one channel (#4 connector C6) with a stand alone DC power. He made measurements in different conditions: turning on/off LV/HV the power for the crates itself and also ramping the HV. He was looking for is 60Hz noise and 200kHz bursts with tens of MHz within the bursts. The conclusion: the 60Hz comes when powering the south HV supply (connected to the card). The 200kHz bursts come when rumping up the HV and stay when the HV is up.
 +
Fernando wanted more tests with more cards and HV modules to see if this is a problem with a particular module/HV crate or a common feature of this CAEN system.
 +
 
 +
- Mike found that for the "problematic" channels (with no signals in the fADC but visible on the scope)  one can actually see something (noise or signal) in the fADC but with a huge DAQ offset of 0xd000. It is not clear yet what is the quality of the signals.
 
   
 
   
 
== FDC update ==
 
== FDC update ==
  
- Lubomir presented a table (xls file linked) with all the problematic cathode channels as identified from the latest DAQ runs. Luke checked these channels with a scope which information is included in the Q-column with color. Information about Anatoly's measurements with scope in March/April (right after insertion) and the attempts to fix these channels is also included. 
+
- The first track going through all the 24 chambers is shown above. It was obtained with Beni's horizontal muon trigger. So far within 4 hours run we found only two such events. There are few more with muons partially crossing the FDC system. Still, this one event help a lot to fix the geometry, the translation table and some bugs in the code. Important is that we see signals from all the cells and all the planes within a cell, upper strips, down strips, and a wire, crossing at the same point, meaning we have 100% efficiency. The space points in the plot are the avalanche positions obtained from the cathodes only and fitted with a 3d line. Next step is to use the drift time information to find the actual hit positions.
 
+
- For 69 of the channels (pink or red color) we suspect the problem is at the detector side (mostly conductive tape, but also connector or pre-amp issues). In the packages (1 to 4) the number of such channels is 4,1,41,23. Ten of these channels were OK in April, but had problems before, except two of them.
+
 
+
- We have 11 channels (green) where we see signals with the scope but not with fADC. However, the fADC channels are OK with another cable; Fernando suspect cable/connector problem. In the fADC data you see overflow or a fixed value at ~2000 and Beni made a list of such channels before.
+
 
+
- Finally, there are 9 channels (yellow) with no signal, but also almost no noise. Some of these were identified before to have problems with the 3M connectors, but the rest may have other issues.
+
  
 
== Electronics ==
 
== Electronics ==
  
- Fernando looked for EMI noise in the hall at the platform. He didn't find anything in the kHz range. The only source of very low noise was the mass flow meters for the BCAL Nitrogen. Dave proposed to check this by turning them off for a while. However, Fernando was not able to get very close to the CDC due to the target work there.
+
- Chris and Nick worked on the CDC testing the "problematic" channels. Most likely the problem is in the 3M connector (but could be somewhere else), so Chris is going to exercise to see if one can open and fix such connector.  
  
- Starting middle of August - September Fernando's group will start checking/fixing/re-routing cables that were not installed properly. Expect short interruptions at that time.
+
- Fernando: Cody is ready with the pulser firmware for fADC125. After some iterations with Bryan, it will be ready for use.
 
+
== Engineering ==
+
== Cathode scan ==
  
- Luke, with help from other people, started working on the scanning project (picture attached): the microscope has been attached to the motion stage, the motor can now be controlled from the computer. The shaft that connects the motor is missing but Tom ordered a new one; the encoder still needs to be connected.
+
- Luke finished the first set of measurements: for a fixed y (along the strips at about 20cm from center) he scanned both sides of all the strips. The data can be explained by using a regular pitch of 5.012 mm without any gaps or change of the pitch values in the different foils. There are still some "jumps" off the expected values in the splicing regions but of the order of 50 microns.
 +
Eugene: how good is the repeatability? Luke: we are counting now the motor revolutions (encoder not connected yet), but if you go in one direction, as the measurements were done, it is accurate to 20 microns. Luke will continue with the scan at other y-values, will make distributions of strip widths and other parameters.
  
 
== Other ==
 
== Other ==
  
- Beni:it's time to start using alcohol in the gas system. Will ask Scott to fill the alcohol bubblers.
+
- Scot replaced the faulty change-over unit for the CO2 on Wednesday. The chiller failed on Friday ( "alarm 12: return low flow flt"), reset didn't help, had to unplug/plug the power. Wesley Moore was working before that using the serial port for the controls, but not when it failed.
 
+
-->
+

Latest revision as of 00:48, 1 April 2015

July 24, 2014 FDC+CDC meeting

Agenda

  1. DAQ (Beni)
  2. CDC status (Mike, Beni)
  3. FDC status First Track through all packages (Lubomir)
  4. Electronics (Chris, Nick)
  5. Cathode scan (Luke)
  6. Other

Instructions for Bluejeans meeting connection

FDC meeting ID: 290664653

Minutes

Participants: Sean (NU), Luke, Chris, Mike, Simon, Beni, Fernando, Eugene, and Lubomir (JLab).

DAQ

- Beni: DAQ doesn't want to crash now, so it's difficult to troubleshoot the problem. Will start big run over the weekend with the new (nonflammable) cable to record the trigger time.

CDC update

- Beni studied the CDC noise once again (all the results are linked above): using a scope on one channel (#4 connector C6) with a stand alone DC power. He made measurements in different conditions: turning on/off LV/HV the power for the crates itself and also ramping the HV. He was looking for is 60Hz noise and 200kHz bursts with tens of MHz within the bursts. The conclusion: the 60Hz comes when powering the south HV supply (connected to the card). The 200kHz bursts come when rumping up the HV and stay when the HV is up. Fernando wanted more tests with more cards and HV modules to see if this is a problem with a particular module/HV crate or a common feature of this CAEN system.

- Mike found that for the "problematic" channels (with no signals in the fADC but visible on the scope) one can actually see something (noise or signal) in the fADC but with a huge DAQ offset of 0xd000. It is not clear yet what is the quality of the signals.

FDC update

- The first track going through all the 24 chambers is shown above. It was obtained with Beni's horizontal muon trigger. So far within 4 hours run we found only two such events. There are few more with muons partially crossing the FDC system. Still, this one event help a lot to fix the geometry, the translation table and some bugs in the code. Important is that we see signals from all the cells and all the planes within a cell, upper strips, down strips, and a wire, crossing at the same point, meaning we have 100% efficiency. The space points in the plot are the avalanche positions obtained from the cathodes only and fitted with a 3d line. Next step is to use the drift time information to find the actual hit positions.

Electronics

- Chris and Nick worked on the CDC testing the "problematic" channels. Most likely the problem is in the 3M connector (but could be somewhere else), so Chris is going to exercise to see if one can open and fix such connector.

- Fernando: Cody is ready with the pulser firmware for fADC125. After some iterations with Bryan, it will be ready for use.

Cathode scan

- Luke finished the first set of measurements: for a fixed y (along the strips at about 20cm from center) he scanned both sides of all the strips. The data can be explained by using a regular pitch of 5.012 mm without any gaps or change of the pitch values in the different foils. There are still some "jumps" off the expected values in the splicing regions but of the order of 50 microns. Eugene: how good is the repeatability? Luke: we are counting now the motor revolutions (encoder not connected yet), but if you go in one direction, as the measurements were done, it is accurate to 20 microns. Luke will continue with the scan at other y-values, will make distributions of strip widths and other parameters.

Other

- Scot replaced the faulty change-over unit for the CO2 on Wednesday. The chiller failed on Friday ( "alarm 12: return low flow flt"), reset didn't help, had to unplug/plug the power. Wesley Moore was working before that using the serial port for the controls, but not when it failed.