Active Volume in LArSoft Tyler Alion tylerdalion@gmail.com April - - PowerPoint PPT Presentation

Active Volume in LArSoft

Tyler Alion tylerdalion@gmail.com April 12, 2016

Easy part: Simple addition to Geometry

• Hard part: Generalize LArG4 electron drift

1

volTPCActive volTPC

U V Z

Active Geometry

TPCGeo

• volTPC
• dimensions
• world transform matrix
• root volume
• volTPCActive
• dimensions
• world transform matrix
• root volume
• Potential confusion in

fiducial cuts…

No way to get Active center

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Active Geometry

(easy fix)

Add TPCGeo function:

• GetActiveCenter(xyz)
• don’t even need to

save new transform with root volume

• GetCenter(xyz) in all

**Geo’s for that matter…

• Add Geometry function:
• GetActiveBounds(xyz)
• Min/Max bounds of all

TPCs / TPCActives

• Standardize fiducial cuts

volTPCActive volTPC

U V Z

GetActiveCenter(double *xyz)

3

Particles crossing wire planes

no simulation in/behind wire planes effects here change per detector

35t track flattens off

Thanks to Tom for providing

Similar ArgoNeuT?? tracks seem to “bounce off”

I’ve seen it somewhere, I can’t find a figure of it

Tick

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Also LongBo and ShortBo -Michelle

Field Cage dead

• space
• (APA)

U V Z Z V U

volTPCActive volTPC

? ?

x y or z

Particles crossing wire planes

no simulation in/behind wire planes effects here change per detector

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Setting the Active Volume

• LArVoxelReadoutGeometry : G4VUserParallelWorld

— Finds and voxelizes every “volTPCActive” — Sets as a LArVoxelReadout Sensitive Detector

• LArVoxelReadout : G4VSensitiveDetector

— ProcessHits passes step info to DriftIonizationElectrons — Drift time calculated based off of step x position — IDEs added to nearest SimChannel for each view — knows field between planes, adds drift time accordingly — Already an if statement to catch activity behind U plane: if(XDrift < 0.) return;

Anything I propose would fit in this if block + the fcl switch. Won’t slow anyone down.

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LArVoxelReadoutGeometry

• fcl option to set entire “volTPC” as

Sensitive Detector

LArVoxelReadout

• if(XDrift < 0. && fWholeTPC)
• check if within yz boundaries of

plane

• drift based off of field between

planes, already known

Field Cage dead

• space
• (APA)

U V Z Z V U

? ?

Proposed Change

to provide realistic feature in MC at wire plane crossing

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“Skipped” planes for example:

• U sees nothing, so we simply do not

save the IDEs here

• V sees… non-bipolar signal? nothing?

Different Detectors

• Definitely see something at crossing,

but what?

• 35t flattens out, LArIAT/ArgoNeuT does

something different

• Can this difference be sufficiently

described with fields already saved?

Field Cage dead

• space
• (APA)

U V Z Z V U

? ?

Problems to Discuss Further

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Takeaway Points

• Standardize active geometry in interface
• Save energy depositions in between wire planes?
• Not a well understood effect, varies
• but there IS an effect that will affect reco
• can be a fcl option, with essentially only one

more “if” for that option

• Brian suggested a drift algorithm base class if

more “if” statements creep in

• Needs more thought

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If you know of any event displays could you point them out to me?

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From LBNE CDR