MC meeting

Monday 15 Jan 2024, 14:00 → 16:00 Europe/Zurich

14:00 → 14:20 MC critical problems on Workshop on Critical Problems

Speakers: Maja Mackowiak-Pawlowska (Warsaw University of Technology (PL)), Mr Yehor Bondar (Jan Kochanowski University (PL))

Brant Rumberger: TPC Response Simulation Overview

Przemek Adrich agreed to help with new detector implementation.

---------------------------------------------------------------------------------------------

Priorities:

TPC geometry, where chamber positions are taken, (Bartosz M. and Antoni)k

 

implementing new detector geometry into GEANT:

MRPC: mrpc branch in SHINE (Aizat), TPC, PSD (Sergey), VD(Pawel, Ivan)

TPC Response: Reconstruction hits->clusters done by the following modules:

TPCLinearElectronDriftSG
ExBCloudPropagatorSG
TPCElectronCloudPropertiesSG
TPCResponseSimulatorSG

Brant's presentation is attached with a description of the algorithm, formulas, and parameters, for example: 

  <TPC id="VTPC2"> 
    <diffusion> 
      <xMoyalScale> 0.0230 </xMoyalScale>
      <yMoyalScale> 0.0260 </yMoyalScale>
    </diffusion>
    <lorentzAngleTangent> -0.327 </lorentzAngleTangent>
    <eventByEventT0> 0 </eventByEventT0>
    <minimalDEPerPathLengthUnit unit="keV"> 3.0 </minimalDEPerPathLengthUnit>
    <nEffectiveElectronsPerPad> 7.0 </nEffectiveElectronsPerPad>
    <nEffectiveElectronsPerWire> 5.0 </nEffectiveElectronsPerWire>
    <zeroSuppressionThreshold> 5 </zeroSuppressionThreshold>  
    <nElectronsPerPathZUnit> 35 </nElectronsPerPathZUnit>

    <sector id="1">
      <ionisationReadout>
	<noiseSigma> 2.1 </noiseSigma>
	<signalToNoiseRatio> 28.0 </signalToNoiseRatio>
      </ionisationReadout>
      <readoutResponse> 
	<gain>
	  <linearTerm> 1.0 </linearTerm>
	  <quadraticTerm> 0.0 </quadraticTerm>
	</gain>
      </readoutResponse>
      <resolution>
	<x unit="cm"> 0.0240 </x>
	<y unit="cm"> 0.0360 </y>
      </resolution>
    </sector>

 

How do we vary these parameters for 2022+ data? At the MC Meeting on 4.12.23, we compared 2023 and 2016 data, and the short observation is:
VTPC: TSlices inc. 3->4, Npads comparable, peak MaxADC decreased x2, peak Charge decreased from 200 to ~150
MTPC: TSlices inc. 3->5, Npads comparable, peak MaxADC decreased from ~60 to ~50,  peak Charge comparable

14:20 → 14:30 Choice of MC tracks

Speaker: Uzair Shah (Jan Kochanowski University (PL))

14:30 → 14:40 New Xe+La MC production

Speaker: Oleksandra Panova (Jan Kochanowski University (PL))

14:40 → 14:50 MC p+p production

Speaker: Yehor Bondar (Jan Kochanowski University (PL))

p_LHT_158_11_beam_mode_v1r21.png

14:50 → 15:00 PbPb30 MC Production

Speaker: Mr Yehor Bondar (Jan Kochanowski University (PL))

redoing bad files in PbPb30, expect ~16M

15:00 → 15:20 First look at MC post LS2

Speaker: Mr Yehor Bondar (Jan Kochanowski University (PL))

I took a look at the pre-LS2 and post-LS2 QA plots you sent me and the
Legacy MC vs Luminance MC vs pre-LS2 QA comparisons. I can summarize as
follows.

(1) The post-LS2 electronics lets the chamber response function into raw
data without processing, which is known to be power-law (long tail) due to
MWPC signal formation physics. The pre-LS2 electronics had an analog
signal shaper in order to get rid of this. The post-LS2 Shine has a
digital implementation for this same correction (the so-called Wiener
filtering). The post-LS2 QA plots are visibly obtained _without_ the
Wiener filter, therefore the number of time slices distribution looks
wide. If the Wiener filtere were applied, the time response is pretty
similar to pre-LS2 electronics (I had detailed study on this). See also:
https://twiki.cern.ch/twiki/pub/NA61/Nov2022Wiener/wiener.pdf
   and
https://twiki.cern.ch/twiki/bin/view/NA61/Nov2022Wiener
Thus, there are two possible strategies:
(A) Minimal working solution: do not update TPC time response in MC, but
then do not use the Wiener filter for MC reco, but use it for the post-LS2
raw data reco.
(B) Purist solution: write a TPC time response distorter for post-LS2 MC,
and use Wiener filter in all reco.
I think, we can live with (A).

(2) The pad response functions look (and should look) pretty much
unchanged after upgrade, in the raw data. If we are satisfied with what we
had pre-LS2, then no upgrade needed here.

(3) For the high multiplicity data, for the sectors having lots of tracks,
Piotr usually lowers the gains (SenseWire HV). This affects VTPC1, VTPC2,
and the high resolution sectors of MTPCs. I am not sure if this is
disturbing for MC. In my opinion, if we don't have manpower, we can
postpone to simulate this, as it has little effect on cluster/track
finding, but more on dE/dx only.

(4) Geometry: this has changed. I think one of the big issues with MC that
it is difficult to track where it takes various detector descriptions
from. Ideally, it should take everything from det::Detector container. If
I remember well, for the geometry this is taken from some custom root
file. I am not familiar with the procedure here, I just remember that it
was a mess and not well documented (Marek Szuba et al).

I think, what is important is to simulate those effects in which we can
count on large calibration imperfections, regarding cluster/track finding.
Of course, we have to fix the geometry. Then, the most important one is
e.g. ExB distortion. Then, the E distortion. The cluster shape simulation
is the least important one, I think, if we correct the raw data with the
above machinery. Of course, it would be nice to simulate everything, but
the above would be my priority list if we are lacking manpower.

Best,
Andras

15:20 → 15:30 PSD in PbPb

Speakers: Andrey Seryakov (St Petersburg State University (RU)), Sergey Morozov (Russian Academy of Sciences (RU))

15:30 → 15:35 Services and files

Speakers: Bartosz Maksiak (National Centre for Nuclear Research (PL)), Maja Mackowiak-Pawlowska (Warsaw University of Technology (PL))

15:35 → 15:40 AOB

Speakers: Andrey Seryakov (St Petersburg State University (RU)), Brant T Rumberger (University of Colorado Boulder (US)), Daria Prokhorova (St Petersburg State University (RU)), Evgeny Andronov (St Petersburg State University (RU)), Jakub Piotr Wlodarczyk (Warsaw University of Technology (PL)), Justyna Monika Cybowska (Warsaw University of Technology (PL)), Maja Mackowiak-Pawlowska (Warsaw University of Technology (PL)), Dr Marcin Michal Bielewicz (National Centre for Nuclear Research (PL)), Mr Yehor Bondar (Jan Kochanowski University (PL))

Hi,

 

I am trying to run Luminance using current Shine master on files from
/eos/experiment/na61/data/Simulation/Pb_Pb_150_18/AMPTdata/5D0enriched_ampt/

 

I am getting an error and a crash:

 

[ERROR] Modules/Simulation/LuminanceSG/G4SHOEPrimaryGenerator.cc:185: GetGeantParticleDefinition: Geant4 doesn't understand PDG particle ID -413

 

If I look into the ROOT PDG table, I get that -413 is one of D mesons.

 

Has anybody run into a similar problem?

 

Cheers,

Antoni