Difference between revisions of "Minutes-11-17-2016"

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# Preparations for the fall 2016 run
 
# Preparations for the fall 2016 run
 
#* CDC (Beni/Naomi/Mike)
 
#* CDC (Beni/Naomi/Mike)
 +
#** CDC [http://www.jlab.org/Hall-D/detector/fdc/fall2016run/CDC_Temps111716.jpg temperatures]  (Naomi, Nick)
 +
#** [[CDC_alcohol| alcohol effect]] (Naomi)
 
#* FDC (Lubomir)
 
#* FDC (Lubomir)
 
#** Noise studies [http://www.jlab.org/Hall-D/detector/fdc/fall2016run/DISCRnoise.bmp noise on FDC discrminators](Fernando, Lubomir)  
 
#** Noise studies [http://www.jlab.org/Hall-D/detector/fdc/fall2016run/DISCRnoise.bmp noise on FDC discrminators](Fernando, Lubomir)  
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# fADC125 (Naomi, Cody, Beni)
 
# fADC125 (Naomi, Cody, Beni)
 
# Other
 
# Other
#* [[CDC_alcohol| alcohol]]
 
 
<!--
 
  
 
= Minutes =
 
= Minutes =
  
Participants: Naomi (CMU) Fernando, Eugene, Cody, Alexander A., Simon, Beni, Mike, and Lubomir (JLab).
+
Participants: Curtis, Mike, Naomi (CMU) Sean (NU) Fernando, Eugene, Alexander A., Beni, Chris, Nick, and Lubomir (JLab).
  
 
== Preparation for the fall 2016 run ==
 
== Preparation for the fall 2016 run ==
  
- Naomi and Beni are looking at the latest CDC data. Cody: there's an issue with one module in the CDC4 crate.  
+
- Naomi: in the last days the temperatures in the CDC have drifted from their standard values. Nick prepared a plot attached above demonstrating this. Will discuss it with Tim. The noise in the CDC turned out to be a result of using different triggers - the noise disappeared once Naomi used the correct trigger type (code provided by Beni).  
  
- Lubomir is analyzing the FDC data from the latest run 21050. Sasha excluded FDC6 and FDC11 for this run due to problems with them, but Cody tested them with his own code and they are fine, suspect software problem.
+
- Naomi showed the effect of the alcohol on the CDC - increased total drift time by a little and increased amplitude (see link).
  
- after the spring 2016 run, Beni stopped the alcohol to be mix in the gas for both CDC and FDC and will put it back next week.  
+
- Fernando and Lubomir studied the noise in the Hall related to high trigger rates. The noise is seen on the FDC TDCs coming from the input to the discriminators. Scope screen - yellow is the trigger at the SD, pink is the discriminator output. On the spectral analyzer the noise had equidistant peaks - ~3.3 MHz apart for 60 kHz trigger rate and ~10 MHz apart for 15 kHz trigger rate - with an amplitude ~10dB in a wide range of 100MHz. The noise is seen everywhere on the crates and also along the signal cables. Fernando: the noise is low, but maybe combined from all the crates might indues measurable signals on the wires (Lubomir), as is the case. Discussions with Sergey after the meeting - the data rates (due to the noise) on some TDC crates are very high limiting the DAQ performance for the high intensity running.    
  
 
== Tracking ==
 
== Tracking ==
  
- Mike showed the timing calibrations for the FDC fADCs and TDCs (plots linked above). The fADC time variations with the runs are due to changes in the look-back parameter that Sasha played with during the running. The TDC time is with respect to TI and jumps by 4ns, but for all detectors, so relatively it doesn't matter. However, Beni found found that once the TI timing (same for all the detector crates) was different from the timing of the trigger crate for some runs.  
+
- Mike reported on his plan for the CDC and FDC alignment (see the link above). On a scale of +/- 250 microns one certainly sees in the FDC residuals some non-uniform features over the area of the chambers. The residuals are from a run with magnetic field and tracking through both CDC and FDC without excluding the corresponding chamber from the track. The plan is to use MILLEPED but before that it requires some good work: fix some issues with the output from the Kalman filter, calculate full co-variance matrix (not only diagonal elements), implement straight line tracking through both CDC and FDC, standardize the geometry and alignment constants.
  
- Mike made a presentation (linked) on his studies of the CDC/FDC transition region. He used straight tracks through the FDC and looked at the residuals w.r.t. the CDC wires. This is the procedure used by Lubomir to find the CDC offsets w.r.t. FDC except that Mike used the standard Simon's tracking. Mike showed there's ~20% more tracks in the 10-30 deg region after applying the offsets. These offsets will be included for the next analysis run.
+
- Sean discussed a plan to improve the tracking simulations (linked). This includes two steps: update the detector hit objects, then study the performance of reconstructed tracks.  
  
== f125 ==
 
 
- Cody is fixing some issues in the timing algorithm pointed out by Naomi. He's replacing a module in CDC4. He doesn't see issues with FDC6 and FDC11 when tested with his soft. Sasha could use these two crates in the last cosmic run.
 
 
 
== Other ==
 
== Other ==
  
- Next meeting in two weeks if not too much busy with the run.
+
- Next meeting in two weeks
 
+
-->
+

Latest revision as of 18:54, 18 November 2016

November 17, 2016 Drift Chamber meeting

Connection

  1. Instructions for Bluejeans meeting connection
  2. Meeting ID: 290664653

Headline text

  1. To join via a Web Browser, go to the page [1] https://bluejeans.com/290664653.

Agenda

  1. Preparations for the fall 2016 run
  2. Tracking
  3. fADC125 (Naomi, Cody, Beni)
  4. Other

Minutes

Participants: Curtis, Mike, Naomi (CMU) Sean (NU) Fernando, Eugene, Alexander A., Beni, Chris, Nick, and Lubomir (JLab).

Preparation for the fall 2016 run

- Naomi: in the last days the temperatures in the CDC have drifted from their standard values. Nick prepared a plot attached above demonstrating this. Will discuss it with Tim. The noise in the CDC turned out to be a result of using different triggers - the noise disappeared once Naomi used the correct trigger type (code provided by Beni).

- Naomi showed the effect of the alcohol on the CDC - increased total drift time by a little and increased amplitude (see link).

- Fernando and Lubomir studied the noise in the Hall related to high trigger rates. The noise is seen on the FDC TDCs coming from the input to the discriminators. Scope screen - yellow is the trigger at the SD, pink is the discriminator output. On the spectral analyzer the noise had equidistant peaks - ~3.3 MHz apart for 60 kHz trigger rate and ~10 MHz apart for 15 kHz trigger rate - with an amplitude ~10dB in a wide range of 100MHz. The noise is seen everywhere on the crates and also along the signal cables. Fernando: the noise is low, but maybe combined from all the crates might indues measurable signals on the wires (Lubomir), as is the case. Discussions with Sergey after the meeting - the data rates (due to the noise) on some TDC crates are very high limiting the DAQ performance for the high intensity running.

Tracking

- Mike reported on his plan for the CDC and FDC alignment (see the link above). On a scale of +/- 250 microns one certainly sees in the FDC residuals some non-uniform features over the area of the chambers. The residuals are from a run with magnetic field and tracking through both CDC and FDC without excluding the corresponding chamber from the track. The plan is to use MILLEPED but before that it requires some good work: fix some issues with the output from the Kalman filter, calculate full co-variance matrix (not only diagonal elements), implement straight line tracking through both CDC and FDC, standardize the geometry and alignment constants.

- Sean discussed a plan to improve the tracking simulations (linked). This includes two steps: update the detector hit objects, then study the performance of reconstructed tracks.

Other

- Next meeting in two weeks