Software for LCTPC Astrid M unnich TPC Review DESY 4. November - - PowerPoint PPT Presentation

Software for LCTPC Astrid M¨ unnich

TPC Review DESY

• 4. November 2013

Astrid M¨ unnich (DESY) Software for LCTPC 1

Overview

Concept: The Framework MarlinTPC Simulation Reconstruction Analysis Missing Items & Challenges Summary & Outlook

Astrid M¨ unnich (DESY) Software for LCTPC 2

The Framework

ILCSoft provides software packages for the linear collider community: LCIO: Common persistent data format, classes used for the TPC: TrackerRawData, TrackerData, TrackerPulse, TrackerHit, Track GEAR: Geometry description: position of modules, design of pad plane, transformation between local and global coordinates Marlin: Processor based reconstruction and analysis framework MarlinTPC: Implementation of reconstruction, analysis and tools needed for data analysis and simulation

Astrid M¨ unnich (DESY) Software for LCTPC 3

MarlinTPC: The Clients

Reconstruction framework for many different technologies:

Pads Pixel GEM MicroMega MicroMega GEM

AFTER raw data ALTRO raw data Pixel raw data Pulse Finding Pulse Finding Cluster Finding Cluster Finding Hit Finding

(pad based)

Hit Finding

(pad based)

Hit Finding

(cluster based)

Hits Tracking

Astrid M¨ unnich (DESY) Software for LCTPC 4

MarlinTPC: The Structure

The packages structure: analysis calibration digitization examples general reconstruction simulation tools tpcconddata validation > 150 processors ≈ 40 developer branches BUT: only < 10 active Marlin Framework Principle:

LCEvent Marlin Processor LCEvent GEAR LCCD

Information about MarlinTPC: https://znwiki3.ifh.de/MarlinTPC/MarlinTPC svn repository: https://svnsrv.desy.de/desy/marlintpc/

Astrid M¨ unnich (DESY) Software for LCTPC 5

Simulation within MarlinTPC

Different simulation approaches with different detail level:

Smearing Geant4 Hit Charge in Voxels Electronics TPCRawData Amplification Drift and Diffusion Drifted Cloud Amplified Cloud Geant4 Hit Electron Cloud Ionisation Amplified Electrons Amplification Drifted Electrons Drift and Diffusion Generator Particle Primary Electrons Ionisation Drift and Diffusion incl. B−Field Distortions B−Field Backdrifting Ions Electrical Field Drift and Diffusion incl. E−Field Distortions E−Field Calculator Primary Ions Electron Cloud Simulation Primary Electron Simulation Simple Digitisation

Simulation for amplification and resistive anode with MicroMegas is missing.

Astrid M¨ unnich (DESY) Software for LCTPC 6

Examples: Electron Cloud Simulation

Simulation of laser calibration system Photodots on cathode Tool to measure field distortions

Underflows Overflows 4.200e+01 8.089e+01 1.198e+02 1.587e+02 1.976e+02 2.364e+02 2.753e+02 3.142e+02 3.531e+02 3.920e+02 4.270e+02

Astrid M¨ unnich (DESY) Software for LCTPC 7

Examples: Primary Electron Simualation

Simulation of small prototypes to verify simulation Use simulation for large ILC TPC Study e.g. dE/dx or ion back flow

0.2 0.4 0.6 0.8 1 50 100 150 200 250 single point resolution in x [mm] drift distance [mm] simulation P5 measurement P5 simulation TDR measurement TDR

Particle ID

1 2 3 4 5 6 7 8 9 10 0.1 1 10 100 dE/dx [keV/cm] particle momentum [GeV] muons electrons protons kaons pions

Ion back flow 500 BX

Astrid M¨ unnich (DESY) Software for LCTPC 8

Field Simulation

CST➋: Simulation of field configurations for a given geometry, e.g. a readout module: Garfield++: Simulation of movement and other processes like amplification

• f charge carriers in electric and

magnetic fields.

Astrid M¨ unnich (DESY) Software for LCTPC 9

Reconstruction

Task: Provide the tools to get from the raw data to a track. Do that for all the different applications: GEMs with pads MicroMegas with pads GEMs with pixel MicroMegas with pixel Simulation Cathode laser dots ... Goal: Use as many common tools as possible. Provide consistent methods and concepts.

Astrid M¨ unnich (DESY) Software for LCTPC 10

Reconstruction Example: Step 1

The first step is a pre-reconstruction:

1

Provide information from data base

2

Reconstruct pulses on each channel

3

Map hardware channel to GEAR pads

4

Reconstruct 3D space points

5

Tracking: Finding and Fitting

6

Obtain calibration factor to transform ADC counts to primary electrons Now determine: Pulse time cut off according to cathode Pulse time shift according to anode position Other calibration info or corrections Fill conditions data base: drift velocity, diffusion, charge conversion etc...

TrackerRawData TrackerRawDataToDataConverter ChannelMapping RowBasedHitFinder TrackFinder + Fitter PulseFinder TrackerData TrackerPulse Track TrackerHit ADC2PrimaryElectron Astrid M¨ unnich (DESY) Software for LCTPC 11

Reconstruction Example: Step 2

1

Apply timing cut

2

Apply time offset

3

Apply correct drift velocity

4

Apply charge conversion during hit finding

5

Correct time offset of RCU

6

Do the tracking again

7

Calculate correction for field distortions

TrackerRawData RawDataCutter ChannelMapping RowBasedHitFinder TrackFinder + Fitter PulseFinder TrackerData TrackerPulse Track TrackerHit DistortionAnalysis TrackerRawDataToDataConverter TimeShiftCorrection

Astrid M¨ unnich (DESY) Software for LCTPC 12

Reconstruction Example: Step 3

1

Correct distortions: Move hits accordingly along row and along z

2

Repeat tracking Similar procedure for all module technologies. Small difference between GEMs and MicroMegas for pulse and hit finding, some due to technology, some to electronics. Fundamentally different between pad and pixel readout up to hit level.

Astrid M¨ unnich (DESY) Software for LCTPC 13

Testbeam Data on the Grid

Storage for raw data and converted LCIO data for all groups: srm://dcache-se-desy.desy.de/pnfs/desy.de/ilc/tpc/ year description/comments electronics RAW avail. LCIO avail. 2010 MicroMegas T2K NO NO 2010 3 Asian GEM ALTRO YES NO 2010 Octopuce (8 Ingrids) Timepix+Muros NO NO 2011 DESY GridGEM ALTRO YES YES 2012 6 MicroMegas

• int. AFTER

YES YES 2012 DESY GridGEM ALTRO YES YES 2012 Asian GEM ALTRO YES YES 2013 7 MicroMegas

• int. AFTER

YES YES 2013 DESY GridGEM ALTRO YES YES LCIO format provides the basis to exchange data!

Astrid M¨ unnich (DESY) Software for LCTPC 14

Conditions Data

LCCD: The Linear Collider Conditions Data toolkit User-defined data classes can be stored in LCIO files or a data base. A Marlin processor provides this information during run-time: Channel mapping Channel quality Pedestals vdrift + diffusion Gas conditions E-field settings B-field settings HV settings Field maps Electronics information Calibration Conditions data base available at DESY: lctpcconddb01.desy.de

Astrid M¨ unnich (DESY) Software for LCTPC 15

Analysis

Task: Evaluate performance of LP modules Single point resolution Hit efficiency Data quality Momentum resolution Needs: In order to produce comparable results Common analysis code Rules and conventions Common cuts Use the same tools → recent progress made, several new analysis processors for common use in the last 3 weeks!

Astrid M¨ unnich (DESY) Software for LCTPC 16

Missing Items & Challenges

Reconstruction: Correction of over-range pulse and dead channel in hits. Correction: Correct field distortion, ideally with a well understood model and not data driven. Calibration: Calibration of electronics and gain uniformity still outstanding. Alignment: Disentangle real geometric misalignment of modules from other effects like distortions. Geometry description needs to able to represent misalignment. Tracking needs to able to handle misalignment.

Astrid M¨ unnich (DESY) Software for LCTPC 17

Summary

A lot of progress has been made within the last 2 years: Simulation: Various detailed simulation chains available within MarlinTPC. External programs are used to simulate electrostatic and magnetic field maps. Reconstruction: Full reconstruction chain available for all technologies. Calibration and correction procedures are starting to develop based on recent testbeam campaigns. Effort to use as much code and tools in common as possible has started again. Analysis: Common rules and tools have been defined. A selection of plots has been agreed on.

Astrid M¨ unnich (DESY) Software for LCTPC 18

Outlook

Tracking Evaluate and compare different available packages Solve tracking issues for pixel readout Corrections Better non data driven correction method for field distortions. Alignment Gain experience with Millepede II mainly for alignment studies, but it can also be used to determine any parameter influencing the position measurement Simulation Readout module with gating grid Continue with simulation of field distortions Continue ion back flow studies and calculations Detailed simulation for MicroMegas dE/dx: Requires good calibration also of the gain stability and homogeneity Momentum Resolution: External reference is needed. Would also be useful for distortion studies.

Astrid M¨ unnich (DESY) Software for LCTPC 19