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July 16

  1. Joe/Gene - spacecharge and gridleak - Having had Gene diagnose that there were issues with the gridleak in the current calibration I went back with his estimated numbers and re-ran it, but there may be problems with that now and it may take another iteration or two to find our way to the correct place to be.
  2. Hal - QA - Didn't call in, but he said at the analysis meeting that he would do more QA (the rest of it).
  3. Rosi/Jan - PPV - Rosi was working on the beam tilt part of it now and it sounds like she is getting good results and everything so it won't hold us up once we get the sc/gl ready.
  4. Willie - BSMD - Showed his progress (see the email he sent around)
  5. Ross - Vernier - See his drupal page
  6. Scott - ETOW gains - See his presentation. He started looking at the gains in each sector now with the data from the timing scans, but using "Scott's method" for calculating the gain (last slide). It looks like sectors 5 and 6 are actually different from 3 and 4 when you use "Scott's method". He thinks he will have a gain for each tower calculated by the end of next week though. So excellent progress there.

June, 25

Present: Gene, Scott, Joe, Jan, Willie, Ross,Rosi

  1. TPC, Gene:
    • TPC alignment used now is old, from run 8
    • Joe produced non-linear SC based on 10 runs , not yet in DB.
    • Units for SC are V/cm^2. Conversion to actual correction used to shift clusters is SC of 0.01 V/cm^2 --> 8.5mm of shift in the X-Y plane for track at eta=0.
    • Few days later Joe generated SC ver 2 based on ~60 runs and differences between SC ver 1 & ver 2 are of 2 mm at the highest ZDC rate of ~170 kHz
    • we need to check if after applying SC the residua are scattered around zero, using different runs
    • Gene will evaluate DCA to the vertex to see if we achieved 2mm accuracy of global tracking
    • Jan investigated chi2/dof for tracking (before SC were applied) and found its average is of 1.5. We discussed how to rescale TPC hit errors to get avr chi2/dof=1.<br> There are 3 critical parameters deciding how big are errors of clusters: *dip angle, * crossing angle, and *track momentum(?not sure?) <br> Few days later Jan check chi2/dof w/ Sc and it was much closer to 1 - perhaps rescaling of hit errors is not necessary.
  2. BSMD was never aligned with TPC for real data - brought by Scott. We could (should) use high pT electrons reco in TPC for alignment. L2W events will be ideal. Jan asked Matt about the change in BTOW geometry last year to add dead material at eta=0. Matt said this change did not affected BSMD geometry model, so we have in reco what we believed was true ca. 1998. It needs to be verified with actual 2009 data.
  3. ETOW gains: Scott got from Alice timing scan data and will analyze them. We discussed reliability of gains for towers with significantly wrong timing when gain correction factor is of 10 or more. It is important to look also at derivative of d_gain/d_timing and flag as bad towers with large correction or large derivative. Details TBD.
  4. beam line constrain: Rosi was finalizing 3D fitter based on Minuit. 3 days later: code is running but convergence is not great, few problems are identified, e.g. too many fit params. Rosi & Jan are working on this - top priority, needed for production to start.
  5. preparation for data production:
    • we want to run over 1.4M of L2W events vs. ~900 M of all events taken in run 9
    • Joe will give presentation motivating this production to PWGC
      #*Before we start production following must happen: <br>- confirmation non-linear SC does improve TPC accuracy<br> - mean chi2/dof should be ~1 <br> - beam line algo by Rosi, Jan must be developed, tested, vetted <br>- beam line algo must be executed over full pp 500 data set and beam line params loaded to Db<br>- problem w/ ADC=0 for ETOW for certain runs needs to be resolved , Ross reminded me it was discovered already in the past, if # of corrupted 'sth' was >40 the whole block was set to 0 - need half day of attention <br>- run list needs to be generated, including sub-list of daq files for the 5% sample-production - this is half day of my work
  6. run QA: ver 3 of run list incorporating peoples run QA prepared so far has been assembled: pp500 run list ver3c , 80% QAed, updated June 29

June 18, 2009

Present: Gene, Scott, Jan, Willie, Hal, Ross

  1. TPC, Gene:
    • non-linear SC(lumi) should provide TPC track accuracy of 2 mm at both ends of the track. We hope Joe will work on this next week, should take a week.
    • We could also use Gene's PCA method of finding a linear combination of scalers (each at first order).
    • since linear SC(lumi) was tuned to lumi equivalent to ZDC base rate of 70kHz, any pp500 run taken at the ZDC rate has current best TPC calibration. Jan: I'll use it for beam line constrain study, see below.
    • beam line constrain : plan A is Rosi & Jan succeed with 3D beam line fit to global tracks w/o intermediate vertex finding. Here are [Media:Beamline-v3.pdf ] as intended and not implemented. If this works Gene needs a ~day to produce beam line constrain for all 39 fills. Plane B is to use Minuit vertex finder which may require significant stats to overcome jitter due to pileup tracks. In such case we would need to provide manpower for ~week long job, Gene would only supervise it. Jan: lets go for plan A.
    • conclusion: once both items are resolved we can ask for production, perhaps 2 weeks from now.
  2. BTOW, ETOW gains - no progress.
  3. BSMD : Willie is working '''slopes for individual strips'''. He run over 10k VPD-minB events and got this [Media:BSMD-strips-Picture 16.png] and spectra [Media:BSMD-strips-Picture 15.png ]. The available 1.5M vpd-minB events should be enough to fit every strip. If not we will merge strips.
  4. BSMD geometry: Scott asked how well we know '''relative position of BSMD vs. TPC'''. It is followed up on emc2-hn . <p> Scott once did [Media:Conversions-distace-Scott.pdf ] in the SVT, attached. <br>The relevant equation is on the bottom left. For the W > e, we have r_1 = 0, r_2 = 2.3 m (approximate radius of BSMD planes), and B = 0.5 T. With these numbers, you get the simple relation<br> dPhi (cm) = 40 / pT (GeV)<br>For example, an electron of 40 GeV pT will deflect in the phi direction by 1 cm relative to the same e of infinite pT. This is probably good to better than a few %.
  5. run QA : Scott is working on his fills.

no meetings for few weeks

May 21, 2009

Agenda:

  • Joe/Gene - TPC calibration progress, touch upon expected beam line constraint accuracy
  • Rosi/Jan - upgrade of PPV to reconstruct vertex in the transverse plane (for better beam line constraint) diagram, blog from Rosi
  • Scott/Alice (question) - ETOW calibration
  • Willie - correcting BSMD pedestal residual vs. fill , example mod 25, all 120 modules, webpage
    *Joe/Jan - production of L2W-stream could start ~June 15
  • AOB

May 14, 2009

no meeting

May 7, 2009

Present: Gene, Scott, Joe, Jan, Willie, Hal, Dave

  1. TPC:
    • determination of twist & sector alignment in progress, another 10 days needed
    • times of Anode HV on/off will be uploaded to DB in a day
  2. ETOW calib:
    • few dead towers needs to be added to DB
    • slopes from timing scans will be used to determine gains for towers, once Alice will come to IUCF and work on this, in ~10 days.
  3. BTOW: pedestals and status tables uploaded to DB. BTOW status tables done & QAed
  4. Hal run QA comments , spreadsheet
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