Difference between revisions of "Mar 23, 2017 Calorimeter"
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# Action Items | # Action Items | ||
# Run preparations | # Run preparations | ||
+ | ## Activities during the down | ||
## LED Monitoring | ## LED Monitoring | ||
# FCAL update | # FCAL update | ||
Line 46: | Line 47: | ||
# Reconstruction and Simulation | # Reconstruction and Simulation | ||
## [https://logbooks.jlab.org/entry/3467614 BCAL Hadronic Efficiencies] (Elton) | ## [https://logbooks.jlab.org/entry/3467614 BCAL Hadronic Efficiencies] (Elton) | ||
+ | ## [https://logbooks.jlab.org/files/2017/03/3468296/charged_clust_updateMar23.pdf BCAL charged clustering update] (Will) | ||
# NIM articles | # NIM articles | ||
− | |||
# Any other business | # Any other business | ||
= Minutes = | = Minutes = | ||
− | ''Attendees: | + | ''Attendees: Elton, Jon, Mark, Adesh (JLab); Sean (NW); Will (CMU); George, Christina (Athens); Andrei, Ahmed (UofR); Matt (IU) |
+ | |||
+ | # Announcements | ||
+ | # Action Items | ||
+ | #* Adesh: The 2 ns jumps happen at low energy. Need to investigate this further | ||
+ | # Run preparations | ||
+ | ## Activities during the down | ||
+ | ##* Comic data taking concluded yesterday | ||
+ | ##* Sasha is updating firmware on all crates | ||
+ | ##* Fcal would like to take random triggers to study electronic noise without beam. This will take a couple of hours. | ||
+ | ##* All data should be taken before major mechanical activity in the hall | ||
+ | ##* Expect to leave electronics on. Bcal chillers will be parked at 18 degrees. | ||
+ | ## LED Monitoring | ||
+ | ##* Looking at spring 2017 data. | ||
+ | ##* Finds band structure (quasi quantization) of rms values. Jon: Sees bands in Fcal base voltages reported at 16 bits that are the result of averages of 10 bit numbers. Could a similar mechanism be at work. | ||
+ | ##* Plotted rms over the run vs channel number. Investigate outliers | ||
+ | ##* High rms of some channels include zero pulses for some runs. Need to find why this happens. Short runs are excluded, so we expect all channels to have entries. | ||
+ | # FCAL update | ||
+ | ## Calibration (Adesh) | ||
+ | ##* Skim files almost completed for all runs. Files copied to IU | ||
+ | ##* Checking stability of constants, e.g. pedestals, over time. | ||
+ | ## Bases (Jon) | ||
+ | ##* Base failures seem to have slowed. 2 failures in the past two weeks. | ||
+ | # BCAL update | ||
+ | # Calibrations | ||
+ | ## pi0 calibrations | ||
+ | ## Timing calibrations | ||
+ | ### [https://logbooks.jlab.org/entry/3468218 Initial timing calibrations] (Mark) | ||
+ | ###* Low level calibrations have been completed as a base for gain calibrations. | ||
+ | ###* Repeating work that George did for spring 2016. Use Run 30895. Some differences, including moving from TGraphs to THF2 histograms, which are more easily scalable into our software. | ||
+ | ###* Fitting z (track) vs Deltat (tup - tdown). Means develop artifacts. Now use FitSlices to determine peak values of distribution vs Deltat. Use these to fit to pol2 | ||
+ | ###* p0 shows a bimodal distribution with Delta z ~ 30 ns ~ 4 ns. Suspect hardware. Discussions with Ben Raydo suggest that the hardware explanation is plausible. Special firmware was developed for Hall B to avoid this problem. Depending on origin of problem, shifts can happen either on a run-by run-basis or upon power. | ||
+ | ###* Need to iterate calibration once tracking fixes are completed. | ||
+ | ###* Sean: concern that constants may not be stable over the entire spring period. Mark: Will check stability using files remaining on the gluon machines. | ||
+ | ###* Shape of residuals is similar for all channels, which suggests the systematics comes from other sources, e.g. tracking. | ||
+ | ### [https://halldweb1.jlab.org/wiki/images/9/91/Semenov-timesimulation-170323.pdf Simulation of BCAL Timing] by A.Semenov & I. Semenova (UofR) | ||
+ | ###* Find that resolutions are reasonably well reproduced compared to data | ||
+ | ###* Use detailed MC to check timing response in MC and compare to data | ||
+ | ###* MC: Find vU - vD ~ 0.3 cm/ns. V decreases with layer number | ||
+ | ###* Data: Find vU - vD ~ 1 cm/ns. V increases with layer number, unlike MC. Not understood why | ||
+ | ###* Checked sigma_z vs E, find ~ 1.2 cm/sqrt(E) + 3 cm, with little systematics. | ||
+ | ## [https://halldweb.jlab.org/wiki/images/9/9d/Resolution_histos_23_03_2017.pdf pi0 Dalitz decay: Comparing thrown and reconstructed quantities] - George | ||
+ | ##* Moved from genr8 (-> geant3), 9 GeV photons, to geant4, polarized photon spectrum | ||
+ | ##* Compare gen vs reconstructed both both modes | ||
+ | ##* Central part of resolution looks like it is ~ 100 MeV, but large tails | ||
+ | ##* Matt: This should be sufficient to investigate efficiencies. | ||
+ | ##* Elton: What kinematic fitting is used? Vertex + p4 to select event sample. | ||
+ | ##* Matt: Concern that this could bias sample. Could look into Vertex + pi0 mass + zero missing energy. | ||
+ | ##* George: Investigate method to determine single photon resolution vs energy. | ||
+ | # Reconstruction and Simulation | ||
+ | ## [https://logbooks.jlab.org/entry/3467614 BCAL Hadronic Efficiencies] (Elton) | ||
+ | ##* Not shown, refer reference for latest updates. | ||
+ | ## [https://logbooks.jlab.org/files/2017/03/3468296/charged_clust_updateMar23.pdf BCAL charged clustering update] (Will) | ||
+ | ##* Charged particle clusterizer | ||
+ | ##* Use wire-based tracks to match to cluster seed. Use axis between track projection and cluster seed. Follow this line to add points to cluster. At this point only use phi dimension; still need to investigate z dependence. | ||
+ | ##* Mark: Would be interesting to investigate the dependence of the results on the layer of the seed. | ||
+ | ##* Find improvement in finding a single shower (when a single shower is generated) with this algorithm compared to neutral clusterizer | ||
+ | ##* Still need to study various systematics, but new algorithm is an improvement over simply using the neutral clusterizer. | ||
+ | ##* Feedback is welcome. Zisis and Andrei will send comments later today. | ||
+ | # NIM articles | ||
+ | #* Elton and Zisis discussed updates on the Bcal NIM after the meeting. | ||
+ | # Any other business |
Latest revision as of 12:46, 23 March 2017
Contents
Video Conferencing Information
Meeting Time: 10:00 a.m.
- To join via a Web Browser, go to the page [1] https://bluejeans.com/907185247.
- To join via Polycom room system go to the IP Address: 199.48.152.152 (bjn.vc) and enter the meeting ID: 907185247.
- To join via phone, use one of the following numbers and the Conference ID: 907185247.
- US or Canada: +1 408 740 7256 or
- US or Canada: +1 888 240 2560
- Upon connection all microphones are automatically muted. To unmute your mike on a Polycom or equivalent unit, enter *4. Unmuting on a computer is trivial as there is a microphone button than can be clicked.
- More information on connecting to bluejeans is available.
Participant Direct Lines
- JLab Phone in CC L207 is 757-269-7084 (usual room)
- JLab Phone: in CC F326 is 757-269-6460
- Phone in the Regina Video-conference Suite is 306-585-4204
- Athens Phone: in Christina's office is 011-30-210-727-6947
Action Items
- Determine number of saturation/underflows that exist in the two LED bias monitoring settings (Ahmed)
- Understand the nature of the peak in the (Fcal propagated to target -RF) satellite peak of -2 ns (Adesh)
- Disable red LED string in dark room to avoid leaving it on in the future. (Adesh)
- Quantify the LED pulser sector jumps within one run (Ahmed)
References
- FCAL HDFCAL log book
- BCAL HDBCAL log book
Tentative Agenda
- Announcements
- Action Items
- Run preparations
- Activities during the down
- LED Monitoring
- FCAL update
- BCAL update
- Calibrations
- pi0 calibrations
- Timing calibrations
- Initial timing calibrations (Mark)
- Simulation of BCAL Timing by A.Semenov & I. Semenova (UofR)
- pi0 Dalitz decay: Comparing thrown and reconstructed quantities - George
- Reconstruction and Simulation
- BCAL Hadronic Efficiencies (Elton)
- BCAL charged clustering update (Will)
- NIM articles
- Any other business
Minutes
Attendees: Elton, Jon, Mark, Adesh (JLab); Sean (NW); Will (CMU); George, Christina (Athens); Andrei, Ahmed (UofR); Matt (IU)
- Announcements
- Action Items
- Adesh: The 2 ns jumps happen at low energy. Need to investigate this further
- Run preparations
- Activities during the down
- Comic data taking concluded yesterday
- Sasha is updating firmware on all crates
- Fcal would like to take random triggers to study electronic noise without beam. This will take a couple of hours.
- All data should be taken before major mechanical activity in the hall
- Expect to leave electronics on. Bcal chillers will be parked at 18 degrees.
- LED Monitoring
- Looking at spring 2017 data.
- Finds band structure (quasi quantization) of rms values. Jon: Sees bands in Fcal base voltages reported at 16 bits that are the result of averages of 10 bit numbers. Could a similar mechanism be at work.
- Plotted rms over the run vs channel number. Investigate outliers
- High rms of some channels include zero pulses for some runs. Need to find why this happens. Short runs are excluded, so we expect all channels to have entries.
- Activities during the down
- FCAL update
- Calibration (Adesh)
- Skim files almost completed for all runs. Files copied to IU
- Checking stability of constants, e.g. pedestals, over time.
- Bases (Jon)
- Base failures seem to have slowed. 2 failures in the past two weeks.
- Calibration (Adesh)
- BCAL update
- Calibrations
- pi0 calibrations
- Timing calibrations
- Initial timing calibrations (Mark)
- Low level calibrations have been completed as a base for gain calibrations.
- Repeating work that George did for spring 2016. Use Run 30895. Some differences, including moving from TGraphs to THF2 histograms, which are more easily scalable into our software.
- Fitting z (track) vs Deltat (tup - tdown). Means develop artifacts. Now use FitSlices to determine peak values of distribution vs Deltat. Use these to fit to pol2
- p0 shows a bimodal distribution with Delta z ~ 30 ns ~ 4 ns. Suspect hardware. Discussions with Ben Raydo suggest that the hardware explanation is plausible. Special firmware was developed for Hall B to avoid this problem. Depending on origin of problem, shifts can happen either on a run-by run-basis or upon power.
- Need to iterate calibration once tracking fixes are completed.
- Sean: concern that constants may not be stable over the entire spring period. Mark: Will check stability using files remaining on the gluon machines.
- Shape of residuals is similar for all channels, which suggests the systematics comes from other sources, e.g. tracking.
- Simulation of BCAL Timing by A.Semenov & I. Semenova (UofR)
- Find that resolutions are reasonably well reproduced compared to data
- Use detailed MC to check timing response in MC and compare to data
- MC: Find vU - vD ~ 0.3 cm/ns. V decreases with layer number
- Data: Find vU - vD ~ 1 cm/ns. V increases with layer number, unlike MC. Not understood why
- Checked sigma_z vs E, find ~ 1.2 cm/sqrt(E) + 3 cm, with little systematics.
- Initial timing calibrations (Mark)
- pi0 Dalitz decay: Comparing thrown and reconstructed quantities - George
- Moved from genr8 (-> geant3), 9 GeV photons, to geant4, polarized photon spectrum
- Compare gen vs reconstructed both both modes
- Central part of resolution looks like it is ~ 100 MeV, but large tails
- Matt: This should be sufficient to investigate efficiencies.
- Elton: What kinematic fitting is used? Vertex + p4 to select event sample.
- Matt: Concern that this could bias sample. Could look into Vertex + pi0 mass + zero missing energy.
- George: Investigate method to determine single photon resolution vs energy.
- Reconstruction and Simulation
- BCAL Hadronic Efficiencies (Elton)
- Not shown, refer reference for latest updates.
- BCAL charged clustering update (Will)
- Charged particle clusterizer
- Use wire-based tracks to match to cluster seed. Use axis between track projection and cluster seed. Follow this line to add points to cluster. At this point only use phi dimension; still need to investigate z dependence.
- Mark: Would be interesting to investigate the dependence of the results on the layer of the seed.
- Find improvement in finding a single shower (when a single shower is generated) with this algorithm compared to neutral clusterizer
- Still need to study various systematics, but new algorithm is an improvement over simply using the neutral clusterizer.
- Feedback is welcome. Zisis and Andrei will send comments later today.
- BCAL Hadronic Efficiencies (Elton)
- NIM articles
- Elton and Zisis discussed updates on the Bcal NIM after the meeting.
- Any other business