-- MarkWard - 27 Sep 2017

Previous Logbook

11-10-2017

  • Wrote a "How too and getting started page" for people to use to do basic dmtpc anaylsis etc it is located here
  • Took data sample for purpose of CR-112 calibration, See Adriana's analysis
  • Discovered Trigger issues with the DAQ
    • Appears to ignore trigger and pulse polarity settings (at least for the charge sensitive pre-amp)
    • Settings in the hptpc_neutron template (copied from one of the ones that shipped with the setup) has triggers on charge channels effectively disabled.
    • Thus it appears we are triggering only when we have a signal on the fast amplifers, ONLY negative going
    • Need to investigate this, possibility of hard coding or bug in the DAQ initialisation.
  • Helped (Tiny bit) with the Ring Turning -> See Zacks page
  • Helped (Tiny Tiny bit) with putting clean tent curtains up
  • Created a 50ohm terminator for SHV connectors for grounding the anodes
  • Grounded All anodes and ground meshes
  • Ramped voltage - breakdown reoccurs at same voltages (630-650v)
  • Cycled the gas, first pumping down to ~3x10^-6 mbar and then back to 40mbar
  • Channels now ramp to 670 without sparking, sparking comes in closer to 680V now
  • Cathode performance is identical, sparking occurs at 3200V
  • Slowly ramped up all channels to 680V, sparking is moderate, though approximately 0.1Hz so we can get a few events between sparks
  • Need to write some error handling into my code, currently segfaults if the first event has no triggers... Thus if the first event is after a spark, it sometimes contains zero triggers.
  • Going to migrate to Linappserv and make a set of compiled programs to improve analysis speed
  • Have 3 data samples in different configurations for analysis

04-10-2017

  • Worked with Adriana on developing the analysis to accept multiple raw files
  • Can identify each peak in the spectrum based upon behavour of the CSP channel.
  • PeakHeights.png
  • hptpc_neutron00_000_018.pnghptpc_neutron00_020_078.png
  • hptpc_neutron00_047_024.png
  • All this is within a single run, a spark appears to trigger the change between each state. Looking through later files, the behavour returns to normal and then back to bad again
  • Applying peak time cut effectively removes this bad behavour from the files.
  • See Adriana's logbook for final plot showing combined files with baseline and time peak time cuts (Also preliminary gain)
  • Shakedown of Amplifiers was good, using the test input, scope traces looked identical for all channels.
  • 3 instances of bad grounding on the boards which has now been fixed. Extra insulation on the inside of the cases has been added.
  • Vessel backfilled with CF4 to 40mbar(30 torr), pressure reached before backfill was 8.44x10^-7 mbar
  • Drift field achieved and stable 3200V (compared to 2700V previously) Getting better smile can at do 100V/cm field at least.
  • Anode voltage frown Bottom left starts to spark at approx 0.5-1Hz when at a voltage of 650V, 50V short of where I usually try and take data to see how everything is behaving.
  • All_Alphas.png

27-09-2017

  • Baseline Analysis,
    • Initially performed my own baseline extraction in order to learn a few things about the raw TFile structure
    • Rewrote the same analysis in the space of a few hours using the dmtpc framework
  • Process is to,
    • Extract the baseline from every trace and push it into a histogram for each channel
    • Fit gaussian/find RMT and define a cut of accepting only waveforms that have a baseline within 8sigma
    • Remove whole events that do not make the cut, Replot and refit.
  • BaseLines_bfandaf.png
  • Pulse height analysis
    • dmtpc framework is mostly defined in Pulse.hh (for anyone who is interested)
    • The getPeak() function extracts the peak and subtracts for baseline offset
    • Further acceptance can be performed based on getPeakTime()
    • Code (and a tutorial on what each part of my macro is doing what has been passed down to Adriana for further modification/development (getPeakTime() cuts which shouldn't take much development
    • Currently my analysis works only one a single file though it should be realitively simple to make it work on a string of files.
    • Quite slow... might concider a compiled version rather than a macro, shakes fist at CINT
  • PeakHeights.png
  • PeakHeights_Cut.png
  • Friday - Adriana and I did a full vacuum system and DMTPC operations tutorial,
    • Made modification to HV feedthrough, changing the connection type to a push on one
    • Applied Kapton insulation over any bare wire, the push on connector and length of the pin.
    • Proved the HV feedthrough operates up to the full capacity of the supply (8kV) in Nitrogen, no sparks or issues
    • Evacuuated vessel
  • Started Testing performance of the Cremat boards, Initially tests look like boards are healthy, but we have devised a full set of tests to be performed in order to check board health and operation of different Amps in each
  • Should be completed in next couple of days, if all checks are good we move onto the grounding and backfill the detector for sample runs
Topic attachments
ISorted ascending Attachment History Action Size Date Who Comment
PNGpng All_Alphas.png r1 manage 810.8 K 04 Oct 2017 - 13:07 MarkWard  
PNGpng BaseLines_bfandaf.png r1 manage 94.9 K 27 Sep 2017 - 12:39 MarkWard  
PNGpng PeakHeights.png r1 manage 36.8 K 27 Sep 2017 - 12:39 MarkWard  
PNGpng PeakHeights_Cut.png r1 manage 15.7 K 27 Sep 2017 - 12:49 MarkWard  
PNGpng hptpc_neutron00_000_018.png r1 manage 185.2 K 04 Oct 2017 - 10:39 MarkWard  
PNGpng hptpc_neutron00_020_078.png r1 manage 186.8 K 04 Oct 2017 - 10:39 MarkWard  
PNGpng hptpc_neutron00_047_024.png r1 manage 187.8 K 04 Oct 2017 - 10:39 MarkWard  
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Topic revision: r5 - 11 Oct 2017 - MarkWard

 
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