Pixel TPC simulations in the ilcsoft ILD framework Kees Ligtenberg - - PowerPoint PPT Presentation

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Oct 13, 2022 211 likes •354 views

Pixel TPC simulations in the ilcsoft ILD framework Kees Ligtenberg Nikhef lepcol gridpix meeting 10 october 2016 Kees Ligtenberg (Nikhef) Pixel TPC simulations 10 october 2016 1 / 13 Outline Overview of simulation framework 1 Simulation

SLIDE 1

Pixel TPC simulations in the ilcsoft ILD framework

Kees Ligtenberg

Nikhef lepcol gridpix meeting

10 october 2016

Kees Ligtenberg (Nikhef) Pixel TPC simulations 10 october 2016 1 / 13

SLIDE 2

Outline

1

Overview of simulation framework

2

Simulation of pads and pixels

3

Muon example event display for pads and pixels

4

Resolution in simulation

Kees Ligtenberg (Nikhef) Pixel TPC simulations 10 october 2016 2 / 13

SLIDE 3

Overview of the ilcsoft framework for the TPC

Ilcsoft is the collection of software for the ILC/ILD Simulation in geant4 using the DD4HEP detector description tool Reconstruction using processors in the modular Marlin framework

◮ Marlin processors should also use DD4HEP, but the TPC processors

still use the deprecated GEAR

Ilcsoft installed on lepcol project space at Nikhef

◮ found at /project/lepcol/ilcsoft/ ◮ setup environment with

source /project/lepcol/ilcsoft/v01-17-10/init ilcsoft.sh

Kees Ligtenberg (Nikhef) Pixel TPC simulations 10 october 2016 3 / 13

SLIDE 4

Overview of the ilcsoft framework for the TPC

Kees Ligtenberg (Nikhef) Pixel TPC simulations 10 october 2016 4 / 13

SLIDE 5

Simulation of pads

x y Volumes are organised as tube shaped layers, there are no pad columns

1 Detector described by DD4HEP geometry is

loaded. Sensitve gas volumes are made

2 Geant4 processes interactions of particle(s)

from gun or event

3 Single hit in TPC is deposited if energy above

threshold (32eV) in a single pad. Position of pad centre crossing is recorded

4 TPC hits are smeared by expected resolution in

TPCDigiProcessor. Hits can migrate to other

pads

5 Smeared hits are used as input for

reconstruction

Kees Ligtenberg (Nikhef) Pixel TPC simulations 10 october 2016 5 / 13

SLIDE 6

Simulation of pixels

Simulate pixels as small pads

◮ Shrink pad size from 6×1 mm to 0.055×0.055 mm ◮ Allow multiple deposits per pixel crossing before smearing ◮ Requires replacement of the the GEAR geometry by the DD4hep

geometry

Kees Ligtenberg (Nikhef) Pixel TPC simulations 10 october 2016 6 / 13

SLIDE 7

Pad event display and muon track display

t¯ t event display single 50 GeV µ− track

Kees Ligtenberg (Nikhef) Pixel TPC simulations 10 october 2016 7 / 13

SLIDE 8

Pixel muon track display

single 50 GeV µ− track

Kees Ligtenberg (Nikhef) Pixel TPC simulations 10 october 2016 8 / 13

SLIDE 9

Hits along track

hitsByDistanceFromOrigin Entries 12937 Mean 1724 Std Dev 544.7 Distance [mm] 500 1000 1500 2000 2500 Hits 200 400 600 800 1000 hitsByDistanceFromOrigin Entries 12937 Mean 1724 Std Dev 544.7

Number of hits by distance from origin

More than 10 000 hits for a 50 GeV muon track for pixels, compared to 170 for pads

Kees Ligtenberg (Nikhef) Pixel TPC simulations 10 october 2016 9 / 13

SLIDE 10

Resolution as function of drift length

z [mm] 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 m] µ [

φ r

σ 50 100 150 200 250 300 350

Simulated resolution Parameterized function for resolution

Resolution is better closer to the endplate, at larger z Simulated resolution is standard deviations of distance to track Function is smearing magnitude

Kees Ligtenberg (Nikhef) Pixel TPC simulations 10 october 2016 10 / 13

SLIDE 11

Orthogonal distance in z slices

m] µ Distance [ 1500 − 1000 − 500 − 500 1000 1500 normalised Hits 0.1 0.2 0.3 0.4 0.5

Z slice 500 < z < 1000 mm, magnitude in XY plane Z slice 1000 < z < 1500 mm, magnitude in XY plane Z slice 1500 < z < 2000 mm, magnitude in XY plane Z slice z > 2000 mm, magnitude in XY plane

Resolution for different z

Kees Ligtenberg (Nikhef) Pixel TPC simulations 10 october 2016 11 / 13

SLIDE 12

Pull diagrams of drift distance in z slices

Distance pull 3 − 2 − 1 − 1 2 3 normalised Hits 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

Z slice 500 < z < 1000 mm, magnitude in XY plane Z slice 1000 < z < 1500 mm, magnitude in XY plane Z slice 1500 < z < 2000 mm, magnitude in XY plane Z slice z > 2000 mm, magnitude in XY plane

Pull is gaussian

Kees Ligtenberg (Nikhef) Pixel TPC simulations 10 october 2016 12 / 13

SLIDE 13

Conclusion

The Ilcsoft framework is installed Pixel sized pad simulation works for particle gun tracks Next steps:

◮ Change pixel TPC hit deposit action. Currently simulation takes hours

for t¯ t event

◮ Look into reconstruction of tracks ◮ Replace GEAR by DD4Hep for reconstruction code Kees Ligtenberg (Nikhef) Pixel TPC simulations 10 october 2016 13 / 13