LArSoft Coordination Meeting

US/Central
Zoom-only

Zoom-only

Description

To connect via Zoom:  Meeting ID 831-443-820

Password distributed with meeting announcement

(See instructions for setting Zoom default to join a meeting with audio and video off: https://larsoft.org/zoom-info/)

PC, Mac, Linux, iOS, Android:  https://fnal.zoom.us/j/831443820

Phone:

H.323:

162.255.37.11 (US West)
162.255.36.11 (US East)
213.19.144.110 (EMEA)
See https://fnal.zoom.us/ for more information
 

At Fermilab:  no in-person presence at the lab for this meeting

 

Release and project report

Discussion

  • Alex Himmel:  Regarding laracorealg#13 (closest TPC to photo-detector), believes the oustanding questions (what questions the geometry needs to answer) has been resolved

    • Contact the author (Gianluca Petrillo) about the status

  • Tom Junk reported excessive mem usage reading older files containing recob::Track with newer releases.

     

    • Found when reading recob::Track v13 (in the root schema evolution versioning system) with recob::Track v17

      • Whenever root's schema evolution occurred, saw very large memory leak

    • Has been reported to root, and the root maintainers have a solution

      • Will require new root version

      • Until then, expect this memory problem to appear

    • Will provide an update on this at a future LCM

 

 

Muve (Wei Mu):  Algorithms for ions and photons calculation

  • Context

    • Two larg4 frameworks:  Legacy, Refactored

    • Three sep algorithms: 

      • Separate, NEST, Correlated

      • Noted two instances of Separate algorithm embedded in  in legacy, one in larsim/ElectronDrift, the other in larsim/LegacyLArG4

  • Algorithms in photon fast simulation

    • Legacy

      • calls IonizationAndScintillation instances in LArG4 module

        • Chooses alg via ISCalculation + LArG4Parameters

        • Fast sim PD response by OpFastScintilation instance according to PhotonVisibilityService

    • Refactored

      • Dedicated IonAndScint module

        • Calc N ions and photons at each energy deposit

        • Choose alg via ISCalc + InputTag

      • PDFastSim module

        • Generate PD response according to GAN (previously discussed)

  • The Separate algorithm

    • Calc N ions based on recomb model + ion yield from LArG4Parameters

    • Calc N photons based on Particle type, scint yield from LArProperties

    • Calculated separately

  • The Correlated algorithm

    • New. Developed after refactored LArG4

    • Considers anti-correl between ion and photons due to electron-ion recomb

      • Uses either Box recomb model, or a saturation model

  • NEST

    • Slightly different between legacy and refactored LArG4

    • NestAlg (legacy),  NESTLAr (refactored)

    • Considers anti-correl Box model / Birks law

    • In refactored, only uses params recorded in EnergyDeposit, and only supports LAr

      • In Legacy, supports Ne, Ar, Kr, Xe + uses parameters beyond EnergyDeposit

    • Goth work identically for LAr

  • An issue with the Separate algorithm

    • N photons in refactored ~15% more than produced in legacy

      • Observed for configs protodunev7_photonvisibilityservice, + protodune_v7_refactored_nowires.gdml

    • Legacy considers EM saturation effect

        • Uses Birks law (G4EmSaturation) to calc visible energy deposit at a step

        • Then calcs N photons based on universal scint yield

          •  

    • Should we port saturation method?

 

Discussion

  • Alex:  just drop support for separate

  • Laura:  Also a problem reported w NEST

    • Muve:  has been fixed

  • Alex:  this is all NEST v1. Mike Mooney said v2 was in the works.

    • Muve:  have not seen this yet.

 

Laura Paulucci Marinho:  LArQL:  a model for LAr ionization and scintillation

  • Work with F. Cavana, F. Marinho, D. Totani

  • Motivation

    • Lack of well defined mech for Scint light emission in LAr

      • ProtoDUNE PDS data analysis results sensitive to some no\t yet adequately sim effects of light from recomb

  • Goals and limits

    • Only separate and NEST were available at the time

      • Started from there to see what to improve

    • Unitary model for ionization and scintillation light as function of energy dep and E field

      • Noted the energy deposition range that is of interest. (see slides...)

  • Know that free ionization and scint light anti-correlated

  • Also know light reduction at low E field and low dE/dx due to electrons escaping recombination

  • LArQL

    • 3 experimental params

      • ionizations per unit E

      • excitations / ionizations

      • fraction of escaping electrons

    • LY obtained from free charge yield

    • Modify Birks charge model correcting for escaping and additional electrons at lower E-field range

    • At high E-field, Birks recovered

  • Described model

  • Comparing to data

    • Works well for charge and scint (ProtoDUNE??)

    • Showed apparent consistency w MicroBooNE

  • LArSoft implementation

    • Use ISCalc

      • Noted that correlated model appeared when working on this implementation

      • So could add this as a correction to the recombination model

    •  

Discussion

  • Seems a reasonable approach

  • MicroBooNE:  might be interested in this, since it improves data / MC agreement

    • Will need to contact people in MicroBooNE. Erica will facilitate this

    • Would require updating their production branch. Changes to the head do not affect them.

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