Status of Pixel Offline Software

F. Djama, Ph. Grenier, S. Miglioranzi

ID week CERN, October 28th 2013

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Introduction• LS1 activities

– Be ready for commissioning and data taking with IBL, nSQP and DBM.– Consolidate and improve present software.– Include radiation effects in simulation and reconstruction.

• Outline– Simulation:

• Geometry

– Digitization– Reconstruction

• Clusterization

– Performance• Tracking• B-tagging

– Software

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Geometry

nSQP

ISIS (IST support) IST DBM

Last months dedicated efforts to deliver a more realistic updated geometry description for the detector and services.

New geometry tag (ATLAS-IBL(3D25)-04-00-01) includes:• last IBL geometry updates.• IPT, IST, ISIS (Inner Positioning and Support tubes). • nSQP (new Service Quarter Panel).• new beam pipe. • DBM (Diamond Beam Monitor).

current geometry is very close to the final one.Some mechanical parts description might slightly change (endblocks, stave rings, ..).

Short term plans: Validate in the next days this new description. freeze it for DC14

S. Elles

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GeometryNew material budget estimations for the latest geometry available:

• detector-only (as in TDR version)• including also Beam Pipe + structures + services

https://twiki.cern.ch/twiki/bin/viewauth/Atlas/SimulationOfPixelGeometryAndMaterialUpgrade2013

S. Elles

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Digitization• IBL requires different digitization models (sensors

technology)

• New PixelDigitization pkg in place:– Code has been optimized.– Different classes per charge model (SiPl, Si3D,DBM).– DBM model exist need to be imported in head tag.

• Extension of DB and Services to IBL:• SW already delivered.• Need to prepare last IBL-aware DB folders.• DBM not included yet needs latest geo tags.

S. Miglioranzi, M. Klein, M. Rudolph, F. Djama

W.-M. Yao

• First data/MC comparison for high incidence on 3D sensors.

• 120 GeV pion at an incidence of θ = 80 (η =2.4 in ATLAS).

• Digitization: inductive model.• Agreement should be better if we check

incidence in real data: perform the sensor alignment.

• Model already in the IBL cache version of the ATLAS software

S. Terzo

Digitization of 3D Sensors at high incidence

Digitization with Irradiation Effects • A lot of progress in implementing charge models for planar sensors,

testing and debuging:– Electric field and Ramo potential mapping from TCAD.– TCAD reproduces well the chosen charge model (V. Chiochia et al., Nuclear

Science, IEEE Transactions on , vol.52, no.4, pp. 1067- 1075, Aug. 2005)– Charge models validated by old results up to 6 1014 neq/ cm2 .– Holes become important in case of trapping !

• Next step: validate charge models after irradiation with test beams of irradiated sensors.

• A similar activity started for 3D sensors .

C. Bertsche, M. Bomben, Ph. Grenier, G. Piacquadio

M. Povoli

M. Bomben - TCAD simulations of planar sensors - ATLAS Pixel week - CERN, 13/06/2013

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Ramo potential: TCAD simulations3D simulation of

ATLAS pixels: ¼ of a 3x3 matrix

Ramo potential: one slice of a 3D simulation (X-Z

plane)

Ramo potential: profile along the bulk

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NN-Clusterization for IBL• NN clustering is default pixel clustering algorithm need to be re-trained for IBL.• In dense cores of high-pt jets, charges deposited by multiple particles can merge into a single

cluster degraded cluster resolution.• NN clustering splits merged clusters and computes positions and errors of subclusters.• • NN training exercise of October 2012 failed (performances not as expected).• Some bugs identified in training code, old MC samples had geo and track problems• New training has now started (100K JZ4W from latest IBL+ATLAS prod used)

first results are promising…Histograms contain hits from all 4 pix barrel layers; Residual: NN-computed position - G4 position

F. De Lorenzi

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Analog Clusterization for IBL• What is used at the moment when running with IBL-geometry

is digital clustering.• Need to make the code more flexible to steer different

clusterization algorithms for different layers.• Develop an analog clustering for IBL.

• Possible optimization for the future:– use NN for cluster splitting.– analog position for the subclusters.

• Work started few days ago…

M. Klein

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• Tracking performances vs PU (40,60,80,100).• At high pileup loss of efficiency & fakes increasing rate have been observed.

Tracking Performance with IBL

Track fake rates vs pt LF track eff vs pt LF track eff vs η

W.-M. Yao, M. Kwok, Y. Wu, Y. Fang, M. Garcia-Sciveres

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Tracking Performance with IBL• Effects of dead modules on tracking

quantities have also been studied:– Disabling 5,10,15% of modules (including

IBL)– The degradation due to disabled modules

up to 15% is modest at few % level

W.-M. Yao, M. Kwok, Y. Wu, Y. Fang, M. Garcia-Sciveres

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B-tagging with IBL0 IBL + 44 disabled Pix modules (with repairs)5 IBL + 44 disabled Pix modules (with repairs)5 IBL + 167 disabled Pix modules (no repairs)5 IBL + 167 disabled Pix modules + readout ineff (no repairs)

• High Pt performance will improve with NN-clustering.• A note in preparation:

• ttbar samples, PU = 0, 60.• Realistic dead module scenario (after nSQP

connection at SR1).• Optimization with b-tag performance group started.

ttbarIP3D+SV1

ttbarIP3D+SV1

WH-> l nu bbarMV1

stdATLAS 14TeVIBL 14TeV

μ=40

A. SchorlemmerB. Di GirolamoG. PiacquadioS. Pires

M. KwokW.-M. YaoY. FangM. Garcia-Sciveres

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Other Topics• Connectivity and ByteStream coding for IBL :

– Realistic IBL Cabling Map joint effort of detector/DAQ/DCS group.– Proposal of FE-I4 ByteStream Cnv (P. Morettini) currently coded (with

help of S. Roe).– Workaround for HLT and FTK: Dummy cabling Map (F. Djama) and FE-I3

inspired ByteStream Cnv (D. Emilyanov).

• Luminosity-induced saturation effects :– At high lumi, hits will be lost due to buffer overflows and busy

electronics.– Simulating FE-I3 readout process:

• Bunches scheme.• Realistic ToT.• Goal: an inefficiency table (eta, lumi) to be used by digitization.

– FE-I4 model also needed.– Next step: simulate MCCs.

• Condition Data Base :– Folders and Services coded.– Ready to be implemented in a release.

L. Franconi

J. Black, T. Nelson

W.-M. Yao

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17.3.11.2Atlas Prod

17.2.11.13Atlas Prod

17.3.12

17.2.12

18.1.0

T0

upgrade

17.7.0.5Atlas Prod

Releases and core sw:

IBL developments and validation studies are currently performed in rel 17.3.X(.Y).• Validated caches used for IBL+ATLAS MC Production so far : 17.3.10.1.Z, IBLProd.

• IBL+ATLAS MC Prod twiki https://twiki.cern.ch/twiki/bin/viewauth/AtlasProtected/AtlasProductionGroupMC12Upgrade• Last validated cache was 17.3.11.1 (contains Supercell info). • Plan to release a full build 17.3.12 in the next days (this week?) including new geo-

related sw. • 17.3.12 will be “in sync” with 17.2.12:

differs for: 64bit, supercell and TrigMC tags.

https://twiki.cern.ch/twiki/bin/viewauth/Atlas/InDetIBL_Example

step Releases

evgen 17.7.2.Y (?)

simulation 17.7.2.Y

digitization + reconstruction

17.3.12.Y

DC14 releases plans:

S. Miglioranzi

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Software Improvements• Large and important activity to improve our software:

– Identifiers– Hard coded numbers– Prepare easy ITK implementation– Code cleaning– …

• Coordinated by S. Miglioranzi.• PixelDigitization package: M. Klein• Geometry: S. Elles• Conditions: W.-M. Yao• We receive valuable help from J. Chapman, N. Styles, R.D. Schaffer…

S. Miglioranzi

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Summary2012/2013 have been crucial years for the development and finalization of the IBL software but still tight schedule ahead !

• Current geometry simulation is realistic:• Preliminary validation is ongoing and PhysVal should start soon.• Plans to use it for DC14.• Only minor changes foreseen in the future.

• Digitization is in place:• Digitization models available for all the different technologies.

• Reconstruction:• Existing reconstruction software robust already working for IBL. • Optimization can be done and it has already started.• Clusterization is a hot topic more people involved on that now.• Involvement of other CP groups has started vital to keep close.

connection and feedback to get the best performance out of IBL.

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ScheduleForseen schedule in april 2013:

Hopefully only few weeks delay…

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Backup

20Tuesday, October 15

Geometry – DBM & DBM servicesIncluded in the new ATLAS-IBL(3D25)-04-yy-zz tags

nSQP

ISIS (IST support) & IST

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22Tuesday, October 15

Geometry – Run1 Pixel Detector

PP0 region required optimization/improvement:• Inner PP0 material overestimated in current GeoModel 2.3<|η|<2.5• SCT extension eff studies sensitive to PP0 region • New improved description by looking at construction files and directly to the dismounted SQP in SR1

Pixel current geometry description: cooling fluid modeling:• Studies of hadronic interactions in cooling fluid. • In pixels show large data/MC discrepancy better modeling needed.

ATLAS-GEO-20-20-04

https://indico.cern.ch/getFile.py/access?contribId=3&resId=0&materialId=slides&confId=252811

hadronic interactions in cooling vs Z

SCT extension efficiency

DataMC

23Tuesday, October 15

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Tracking ActivitiesID Alignment:• Code developments/adaptation to include IBL already started.• Alignment of the IBL/Pixels during cosmic runs.• Further understanding of Silicon deformation.• Improving run-by-run alignment, reduce track parameters systematics…

Vertex Reconstruction:• Improve the power of the vertex reconstruction as in-time pile-up estimator in the

next run.• Work is ongoing on the seeding algorithm. • New Tracking +IBL re-optimization is starting now…