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Merged
f3sch merged 4 commits into from
Oct 10, 2025
Merged

ITS3: improvements for simulation and reconstruction #14685

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f64241c
ITS3: add some services material and update MatLUT macro
f3sch Sep 22, 2025
3d7fcdb
ITS3: ensure matrices are cached
f3sch Sep 23, 2025
a6b813f
ITS3: remove unnecessary recalculation of trackingframe
f3sch Sep 25, 2025
0266a2b
ITS3: fix longeron length to not clip into Hring
f3sch Oct 2, 2025
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3 changes: 0 additions & 3 deletions Detectors/ITSMFT/ITS/base/include/ITSBase/GeometryTGeo.h
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Expand Up @@ -333,9 +333,6 @@ class GeometryTGeo : public o2::itsmft::GeometryTGeo
/// Sym name of the chip in the given layer/halfbarrel/stave/substave/module
static const char* composeSymNameChip(int lr, int hba, int sta, int ssta, int mod, int chip, bool isITS3 = false);

// create matrix for transformation from tracking frame to local one for ITS3
const Mat3D getT2LMatrixITS3(int isn, float alpha);

TString getMatrixPath(int index) const;

/// Get the transformation matrix of the SENSOR (not necessary the same as the chip)
Expand Down
13 changes: 0 additions & 13 deletions Detectors/ITSMFT/ITS/base/src/GeometryTGeo.cxx
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Expand Up @@ -899,19 +899,6 @@ TGeoHMatrix& GeometryTGeo::createT2LMatrix(int isn)
return t2l;
}

//__________________________________________________________________________
const o2::math_utils::Transform3D GeometryTGeo::getT2LMatrixITS3(int isn, float alpha)
{
// create for sensor isn the TGeo matrix for Tracking to Local frame transformations with correction for effective thickness
static TGeoHMatrix t2l;
t2l.Clear();
t2l.RotateZ(alpha * RadToDeg()); // rotate in direction of normal to the tangent to the cylinder
const TGeoHMatrix& matL2G = getMatrixL2G(isn);
const auto& matL2Gi = matL2G.Inverse();
t2l.MultiplyLeft(&matL2Gi);
return Mat3D(t2l);
}

//__________________________________________________________________________
int GeometryTGeo::extractVolumeCopy(const char* name, const char* prefix) const
{
Expand Down
25 changes: 19 additions & 6 deletions Detectors/Upgrades/ITS3/base/include/ITS3Base/SpecsV2.h
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Expand Up @@ -28,9 +28,9 @@
// color: for visulisation
namespace o2::its3::constants
{
constexpr double cm{1e+2}; // This is the default unit of TGeo so we use this as scale
constexpr double mu{1e-6 * cm};
constexpr double mm{1e-3 * cm};
constexpr double cm{1.0}; // This is the default unit of TGeo so we use this as scale
constexpr double mu{1e-4 * cm};
constexpr double mm{1e-1 * cm};
namespace pixelarray
{
constexpr double width{9.197 * mm};
Expand Down Expand Up @@ -102,13 +102,14 @@ constexpr double lengthSensitive{nRSUs * rsu::length};
namespace carbonfoam
{
// TODO: Waiting for the further information from WP5(Corrado)
constexpr double longeronsWidth{2.0 * mm}; // what is the height of the longerons?
constexpr double longeronsLength{263 * mm}; // from blueprint
constexpr double HringLength{6.0 * mm}; // from blueprint
constexpr double longeronsWidth{2.0 * mm}; // what is the height of the longerons?
constexpr double longeronsLength{segment::length - 2 * HringLength}; // 263mm from blueprint; overrriden to be consitent
constexpr double edgeBetwChipAndFoam{1.0 * mm}; // from blueprint but not used cause forms are already overlapping
constexpr double gapBetwHringsLongerons{0.05 * mm}; // from blueprint
constexpr std::array<int, 3> nHoles{11, 11, 11}; // how many holes for each layer?
constexpr std::array<double, 3> radiusHoles{1.0 * mm, 1.0 * mm, 2.0 * mm}; // what is the radius of the holes for each layer?
constexpr std::array<double, 3> radiusHoles{1.0 * mm, 1.0 * mm, 2.0 * mm}; // TODO what is the radius of the holes for each layer?
constexpr double thicknessOuterFoam{7 * mm}; // TODO: lack of carbon foam radius for layer 2, use 0.7 cm as a temporary value
constexpr EColor color{kGray};
} // namespace carbonfoam
namespace metalstack
Expand Down Expand Up @@ -212,6 +213,18 @@ inline bool isDetITS3(T detID)
}

} // namespace detID

// services
namespace services
{
// FIXME these value are hallucinated since this not yet defined
constexpr double thickness{2.2 * mm}; // thickness of structure
constexpr double radiusInner{radiiOuter[2] + carbonfoam::thicknessOuterFoam}; // inner radius of services
constexpr double radiusOuter{radiusInner + thickness}; // outer radius of services
constexpr double length{20 * cm}; // length
constexpr EColor color{kBlue};
} // namespace services

} // namespace o2::its3::constants

#endif
11 changes: 3 additions & 8 deletions Detectors/Upgrades/ITS3/macros/align/CheckResidualsITS3.C
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Expand Up @@ -66,16 +66,11 @@ std::optional<Cluster> propagateTo(Track& trk, const o2::itsmft::CompClusterExt&
++cTotal;
auto chipID = clus.getSensorID();
float sigmaY2{0}, sigmaZ2{0}, sigmaYZ{0};
auto isITS3 = o2::its3::constants::detID::isDetITS3(chipID);
const float alpha = o2::its::GeometryTGeo::Instance()->getSensorRefAlpha(clus.getSensorID()); // alpha for the tracking frame
const auto locC = o2::its3::ioutils::extractClusterData(clus, pattIt, mDict, sigmaY2, sigmaZ2); // get cluster in sensor local frame with errors
Point3D trkC;
auto isITS3 = o2::its3::constants::detID::isDetITS3(chipID);
if (isITS3) {
trkC = o2::its::GeometryTGeo::Instance()->getT2LMatrixITS3(chipID, alpha) ^ (locC); // cluster position in the tracking frame
} else {
trkC = o2::its::GeometryTGeo::Instance()->getMatrixT2L(chipID) ^ (locC); // cluster position in the tracking frame
}
const auto gloC = o2::its::GeometryTGeo::Instance()->getMatrixL2G(chipID)(locC); // global cluster position
Point3D trkC = o2::its::GeometryTGeo::Instance()->getMatrixT2L(chipID) ^ (locC); // cluster position in the tracking frame
const auto gloC = o2::its::GeometryTGeo::Instance()->getMatrixL2G(chipID)(locC); // global cluster position
const auto bz = o2::base::Propagator::Instance()->getNominalBz();

// rotate the parameters to the tracking frame then propagate to the clusters'x
Expand Down
124 changes: 60 additions & 64 deletions Detectors/Upgrades/ITS3/macros/test/buildMatBudLUT.C
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Expand Up @@ -18,6 +18,7 @@
#include "DetectorsBase/GeometryManager.h"
#include "ITSMFTReconstruction/ChipMappingITS.h"
#include "ITS3Simulation/DescriptorInnerBarrelITS3.h"
#include "ITS3Base/SpecsV2.h"
#include "CommonUtils/NameConf.h"
#include <TFile.h>
#include <TSystem.h>
Expand All @@ -30,7 +31,7 @@ o2::base::MatLayerCylSet mbLUT;

bool testMBLUT(const std::string& lutFile = "matbud.root");

bool buildMatBudLUT(int nTst = 30, int maxLr = -1, const std::string& outFile = "matbud.root", const std::string& geomName = "");
bool buildMatBudLUT(int nTst = 60, int maxLr = -1, const std::string& outFile = "matbud.root", const std::string& geomName = "");

struct LrData {
float rMin = 0.f;
Expand All @@ -50,7 +51,7 @@ bool buildMatBudLUT(int nTst, int maxLr, const std::string& outFile, const std::
auto geomName = o2::base::NameConf::getGeomFileName(geomNameInput);
if (gSystem->AccessPathName(geomName.c_str())) { // if needed, create geometry
std::cout << geomName << " does not exist. Will create it\n";
gSystem->Exec("$O2_ROOT/bin/o2-sim -n 0");
gSystem->Exec("$O2_ROOT/bin/o2-sim -n 0 --detectorList ALICE2.1");
}
o2::base::GeometryManager::loadGeometry(geomNameInput);
configLayers();
Expand All @@ -62,7 +63,7 @@ bool buildMatBudLUT(int nTst, int maxLr, const std::string& outFile, const std::
}
for (int i = 0; i < maxLr; i++) {
auto& l = lrData[i];
printf("L:%3d %6.2f<R<%6.2f ZH=%5.1f | dz = %6.2f drph = %6.2f\n", i, l.rMin, l.rMax, l.zHalf, l.dZMin, l.dRPhiMin);
printf("L:%3d %6.4f<R<%6.4f ZH=%5.4f | dz = %6.4f drph = %6.4f\n", i, l.rMin, l.rMax, l.zHalf, l.dZMin, l.dRPhiMin);
mbLUT.addLayer(l.rMin, l.rMax, l.zHalf, l.dZMin, l.dRPhiMin);
}

Expand Down Expand Up @@ -185,87 +186,78 @@ void configLayers()
const float kToler = 1e-3; //
float drStep = 0.f, zSpanH = 0.f, zBin = 0.f, rphiBin = 0.f, phiBin = 0.f;

o2::itsmft::ChipMappingITS mp;
int nStave = 0;
// rMin rMax zHalf
lrData.emplace_back(0.0f, 1.65f, 30.f);
// Vacuum inside beam pipe
lrData.emplace_back(0.0f, 1.6f, 30.f);

// beam pipe
lrData.emplace_back(lrData.back().rMax, 1.8f, 30.f);
lrData.emplace_back(lrData.back().rMax, 1.65f, 30.f);

//===================================================================================
// ITS3 Inner Barrel
drStep = 0.2;
drStep = 0.1;
zSpanH = 20.;
rphiBin = 0.2; // 0.1
zBin = 0.5;
float drStepChip = 0.054; // gap and chip width
float drStepChip4Layer = 0.074; // gap and chip width
rphiBin = 0.1;
zBin = 0.1;

// Layer 1
lrData.emplace_back(LrData(1.8f, 1.8f + drStepChip, zSpanH, zBin, rphiBin));
// Air
do {
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
} while (lrData.back().rMax < 2.4f - drStep + kToler);
lrData.emplace_back(LrData(lrData.back().rMax, 2.4f, zSpanH, zBin, rphiBin));
// air and sensitive layers
for (int iLayer{0}; iLayer < (int)o2::its3::constants::nLayers; ++iLayer) {
lrData.emplace_back(lrData.back().rMax, o2::its3::constants::radiiInner[iLayer], zSpanH, zBin, rphiBin);
lrData.emplace_back(lrData.back().rMax, o2::its3::constants::radiiOuter[iLayer], zSpanH, zBin, rphiBin);
}

// Layer 2
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStepChip, zSpanH, zBin, rphiBin));
// Air
do {
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
} while (lrData.back().rMax < 3.0f - drStep + kToler);
lrData.emplace_back(LrData(lrData.back().rMax, 3.0f, zSpanH, zBin, rphiBin));
rphiBin = 0.1;
zBin = 0.5;

// Layer 3
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStepChip, zSpanH, zBin, rphiBin));
// services
lrData.emplace_back(lrData.back().rMax, o2::its3::constants::services::radiusOuter, zSpanH, zBin, rphiBin);

//===================================================================================
// air space between Inner and Middle Barrels
int nStave = 0;
zSpanH = 40.;
zBin = 5.;
rphiBin = 2.;
lrData.emplace_back(LrData(lrData.back().rMax, 19.0, zSpanH, zBin, rphiBin));
lrData.emplace_back(lrData.back().rMax, 19.0, zSpanH, zBin, rphiBin);

//===================================================================================
// ITS Middle Barrel
o2::itsmft::ChipMappingITS mp;
nStave = mp.getNStavesOnLr(3); // Lr 3
zSpanH = 55.;
zBin = 0.5;
drStep = 0.2;
drStep = 0.3;
do {
auto rmean = lrData.back().rMax + drStep / 2;
rphiBin = rmean * TMath::Pi() * 2 / (nStave * 10);
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
} while (lrData.back().rMax < 20.5 + kToler);
lrData.emplace_back(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin);
} while (lrData.back().rMax < 21.4 - kToler);

drStep = 0.5;
do {
auto rmean = lrData.back().rMax + drStep / 2;
rphiBin = rmean * TMath::Pi() * 2 / (nStave * 10);
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
} while (lrData.back().rMax < 24. + kToler);
lrData.emplace_back(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin);
} while (lrData.back().rMax < 23.4 - kToler);

nStave = mp.getNStavesOnLr(3); // Lr 4
drStep = 0.2;
do {
auto rmean = lrData.back().rMax + drStep / 2;
rphiBin = rmean * TMath::Pi() * 2 / (nStave * 10);
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
} while (lrData.back().rMax < 25.6 + kToler);
lrData.emplace_back(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin);
} while (lrData.back().rMax < 26.2 - kToler);
drStep = 0.5;
do {
auto rmean = lrData.back().rMax + drStep / 2;
rphiBin = rmean * TMath::Pi() * 2 / (nStave * 10);
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
} while (lrData.back().rMax < 29. + kToler);
lrData.emplace_back(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin);
} while (lrData.back().rMax < 29. - kToler);

//===================================================================================

// air space between Middle and Outer Barrels
zSpanH = 80.f;
lrData.emplace_back(LrData(lrData.back().rMax, 33.5, zSpanH));
lrData.emplace_back(lrData.back().rMax, 33.5, zSpanH);

//===================================================================================
// ITS Outer barrel
Expand All @@ -276,62 +268,66 @@ void configLayers()
do {
auto rmean = lrData.back().rMax + drStep / 2;
rphiBin = rmean * TMath::Pi() * 2 / (nStave * 10);
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
} while (lrData.back().rMax < 36. + kToler);
lrData.emplace_back(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin);
} while (lrData.back().rMax < 36. - kToler);

drStep = 1.;
do {
auto rmean = lrData.back().rMax + drStep / 2;
rphiBin = rmean * TMath::Pi() * 2 / (nStave * 10);
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
} while (lrData.back().rMax < 38.5 + kToler);
lrData.emplace_back(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin);
} while (lrData.back().rMax < 38.5 - kToler);

nStave = mp.getNStavesOnLr(6); // Lr 6
drStep = 0.25;
do {
auto rmean = lrData.back().rMax + drStep / 2;
rphiBin = rmean * TMath::Pi() * 2 / (nStave * 10);
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
} while (lrData.back().rMax < 41. + kToler);
lrData.emplace_back(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin);
} while (lrData.back().rMax < 41. - kToler);

drStep = 1.;
do {
auto rmean = lrData.back().rMax + drStep / 2;
rphiBin = rmean * TMath::Pi() * 2 / (nStave * 10);
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
} while (lrData.back().rMax < 44. + kToler);
lrData.emplace_back(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin);
} while (lrData.back().rMax < 44. - kToler);

//===================================================================================

zSpanH = 100.f;
zBin = 5.;
lrData.emplace_back(LrData(lrData.back().rMax, 47., zSpanH, zBin));
lrData.emplace_back(lrData.back().rMax, 44.8, zSpanH, zBin);
lrData.emplace_back(lrData.back().rMax, 46.2, zSpanH, zBin);
lrData.emplace_back(lrData.back().rMax, 47.0, zSpanH, zBin);

drStep = 2.;
zBin = 5.;
rphiBin = 2.;
do {
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
} while (lrData.back().rMax < 53. + kToler);
lrData.emplace_back(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin);
} while (lrData.back().rMax < 55. - kToler);

zSpanH = 120.f;
lrData.emplace_back(LrData(lrData.back().rMax, 56.5, zSpanH));
lrData.emplace_back(lrData.back().rMax, 56.5, zSpanH);
lrData.emplace_back(lrData.back().rMax, 60.5, zSpanH);
lrData.emplace_back(lrData.back().rMax, 61.5, zSpanH);

zSpanH = 150.f;
drStep = 4.;
drStep = 3.5;
zBin = 15.;
rphiBin = 10;
do {
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
} while (lrData.back().rMax < 68.5 + kToler);
lrData.emplace_back(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin);
} while (lrData.back().rMax < 68.5 - kToler);

zSpanH = 250.f;
zBin = 25.;
rphiBin = 5;
{
auto rmean = (lrData.back().rMax + 76) / 2.;
rphiBin = rmean * TMath::Pi() * 2 / (NSect * 2);
lrData.emplace_back(LrData(lrData.back().rMax, 76, zSpanH, zBin, rphiBin));
lrData.emplace_back(lrData.back().rMax, 76, zSpanH, zBin, rphiBin);
}
// TPC inner vessel
// up to r = 78.5
Expand All @@ -340,33 +336,33 @@ void configLayers()
{
auto rmean = (lrData.back().rMax + 78.5) / 2;
rphiBin = rmean * TMath::Pi() * 2 / (NSect * 12);
lrData.emplace_back(LrData(lrData.back().rMax, 78.5, zSpanH, zBin, rphiBin));
lrData.emplace_back(lrData.back().rMax, 78.8, zSpanH, zBin, rphiBin);
}
//
zSpanH = 250.f;
zBin = 2;
{
auto rmean = (lrData.back().rMax + 78.5) / 2;
rphiBin = rmean * TMath::Pi() * 2 / (NSect * 12);
lrData.emplace_back(LrData(lrData.back().rMax, 84.5, zSpanH, zBin, rphiBin));
lrData.emplace_back(lrData.back().rMax, 84.5, zSpanH, zBin, rphiBin);
}

// TPC drum
zSpanH = 250.f;
lrData.emplace_back(LrData(lrData.back().rMax, 250.0, zSpanH));
lrData.emplace_back(lrData.back().rMax, 250.0, zSpanH);

//===============================

// TPC outer vessel
zSpanH = 247.f; // ignore large lumps of material at |z|>247
rphiBin = 2.;
zBin = 3.;
lrData.emplace_back(LrData(lrData.back().rMax, 258., zSpanH, zBin, rphiBin));
lrData.emplace_back(lrData.back().rMax, 258., zSpanH, zBin, rphiBin);

zSpanH = 247.f; // ignore large lumps of material at |z|>247
rphiBin = 2.;
zBin = 999.; // no segmentation in Z
lrData.emplace_back(LrData(lrData.back().rMax, 280., zSpanH, zBin, rphiBin));
lrData.emplace_back(lrData.back().rMax, 280., zSpanH, zBin, rphiBin);

// TRD

Expand All @@ -376,7 +372,7 @@ void configLayers()
do {
auto rmean = lrData.back().rMax + drStep / 2;
rphiBin = rmean * TMath::Pi() * 2 / (NSect * 12);
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
lrData.emplace_back(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin);
} while (lrData.back().rMax < 370);

// TOF
Expand All @@ -387,7 +383,7 @@ void configLayers()
do {
auto rmean = lrData.back().rMax + drStep / 2;
rphiBin = rmean * TMath::Pi() * 2 / (NSect * 12);
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
lrData.emplace_back(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin);
} while (lrData.back().rMax < 400);

// rest
Expand All @@ -398,7 +394,7 @@ void configLayers()
zSpanH = lrData.back().rMax;
auto rmean = lrData.back().rMax + drStep / 2;
rphiBin = rmean * TMath::Pi() * 2 / (NSect * 12);
lrData.emplace_back(LrData(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin));
lrData.emplace_back(lrData.back().rMax, lrData.back().rMax + drStep, zSpanH, zBin, rphiBin);
} while (lrData.back().rMax < 500);
}

Expand Down
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