-- MarkWard - 27 Sep 2017

Previous Logbook


  • Lots of meetings with Sam / Cryovac, good news is that the vessel should 'should' be here today, keep fingers crossed.
    • We aquired quotes from kingsbury for cranage in preparation for our own shipping options
    • Speciality Spanish Transport, quote was lowered and we accepted
    • Southern Cranes and Access gave an insane quote, I think this was in response to bad communications between SST and cryovac and themselves which basically involved SST demanding a quote without giving them any information about the Job. So... knowing or believing they had no options, they quoted 1500 ish... which Cryovac (as much as they are not in a position to complain really) identified as crazy.
    • We provided Cryovac with our quote from Kingsbury
    • Cryovac contracted Kingsbury
  • Got my simple diagnoistic tool working on m3daq
    • I made a sym link into /home/dmatter/bin (i think, i cant check, m3daq is offline for the delivery)
    • This means the program can be used from any command line location
    • Invoked by rawAna.exe - if given with no options it will print the usage directions and flags
    • For looking quickly at a root file and rumping the number of events/triggers point rawAna.exe at a raw root file with no arguments
    • -d dumps waveforms to screen ->really fast, much better than using a CINT macro
    • -c dumps CCD images
    • -d -c dumps both to screen
    • It can be used for offline analysis, currently it will do baseline cuts, peak time cuts, find peakheights for the charge channels and output 4 histograms. baseline sigma cut and time cut can be added using appropriate flags (see useage)
  • Wrote small script for exporting fits file using the DMTPC image library for Kulveer to use
  • Lab cleanup, tidy with the team, My task was mostly disconnecting and tidying away all cables and moving the DAQ computer and electronics rack.
  • Shoring props are in place, clean tent has not fallen over... yet


  • Practiced some mesh stretching, (mostly a helper with Zack and the team)
    • Lots of intersting things learnt
  • Started writing a tool for doing quick diagnostics on data files from DMTPC,
    • Very very fast at dumping waveforms to screen, which is initially the most useful use of it, to check what triggers look like
    • Optionally can dump CCD images along side the waveforms. So we can visually pair up waveforms and Events
    • Slowly updating it to perform baseline cuts given a list of files and generally have it do all of what we usually do in Macros
    • Motivation... CINT IS BAD AND SLOOOOW
    • Already this code appears much faster
  • TPC rail mount designs -> Not got a full assembly drawing yet, though have had a few communications with machine ship, the rails are advancing and hopefully should be out soon.
  • Reviewing Drawings with Zack.
  • Chamber Shipping Drama... mostly Zack doing the waving of sticks at Sam, Adriana speaking to various spanish transport companies.
  • I have spoken to the company wh lifted the DMTPC vessel, they are coming tomorrow to scope the area and will quote us for a UK lift.
  • c7eb6fc7c3dd4bdfc5dcd3f6c97209da.gif


  • 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


  • 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


  • 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
GIFgif c7eb6fc7c3dd4bdfc5dcd3f6c97209da.gif r1 manage 376.9 K 18 Oct 2017 - 13:31 MarkWard  
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: r8 - 25 Oct 2017 - MarkWard

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