ITS3: Add metalstack to geometry

Author: f3sch

Detectors/Upgrades/ITS3/base/include/ITS3Base/SpecsV2.h

@@ -106,16 +106,25 @@ constexpr std::array<int, 3> nHoles{11, 11, 11};                          // how
 constexpr std::array<float, 3> radiusHoles{1.0 * mm, 1.0 * mm, 2.0 * mm}; // what is the radius of the holes for each layer?
 constexpr EColor color{kGray};
 } // namespace carbonfoam
+namespace metalstack
+{
+constexpr float thickness{5 * mu}; // physical thickness of the copper metal stack
+constexpr float length{segment::length};
+constexpr float width{segment::width};
+constexpr EColor color{kBlack};
+} // namespace metalstack
 constexpr unsigned int nLayers{3};
 constexpr unsigned int nTotLayers{7};
 constexpr unsigned int nSensorsIB{2 * nLayers};
 constexpr float equatorialGap{1 * mm};
 constexpr std::array<unsigned int, nLayers> nSegments{3, 4, 5};
-constexpr float thickness{50 * mu};                                                                                                  //< Physical Thickness of chip
-constexpr float effThickness{66 * mu};                                                                                               //< Physical thickness + metal substrate
+constexpr float epitaxialThickness{10 * mu};
+constexpr float psubThickness{40 * mu};
+constexpr float thickness{epitaxialThickness + psubThickness};                                                                       // physical thickness of chip
+constexpr float effThickness{epitaxialThickness + psubThickness / 2.0};                                                              // correction to the epitaxial layer
 constexpr std::array<float, nLayers> radii{19.0006 * mm, 25.228 * mm, 31.4554 * mm};                                                 // middle radius e.g. inner radius+thickness/2.
-constexpr std::array<float, nLayers> radiiInner{radii[0] - thickness / 2.f, radii[1] - thickness / 2.f, radii[2] - thickness / 2.f}; // inner radius
-constexpr std::array<float, nLayers> radiiOuter{radii[0] + thickness / 2.f, radii[1] + thickness / 2.f, radii[2] + thickness / 2.f}; // inner radius
+constexpr std::array<float, nLayers> radiiInner{radii[0] - thickness / 2.0, radii[1] - thickness / 2.0, radii[2] - thickness / 2.0}; // inner radius
+constexpr std::array<float, nLayers> radiiOuter{radii[0] + thickness / 2.0, radii[1] + thickness / 2.0, radii[2] + thickness / 2.0}; // inner radius
 namespace detID
 {
 constexpr unsigned int mDetIDs{2 * 12 * 12 * 12};                //< 2 Hemispheres * (3,4,5=12 segments in a layer) * 12 RSUs in a segment * 12 Tiles in a RSU

Detectors/Upgrades/ITS3/macros/test/TestSensorGeometry.C

@@ -45,7 +45,7 @@ void TestSensorGeometry(bool checkFull = false)
   if (checkFull) {
     gGeoManager->CheckGeometryFull();
   }
-  gGeoManager->CheckOverlaps(0.0001);
+  gGeoManager->CheckOverlaps(0.00001);
   TIter nextOverlap{gGeoManager->GetListOfOverlaps()};
   while ((obj = (TObject*)nextOverlap())) {
     LOGP(info, "Overlap in {}", obj->GetName());

Detectors/Upgrades/ITS3/simulation/include/ITS3Simulation/ITS3Layer.h

@@ -82,6 +82,7 @@ class ITS3Layer
   TGeoMedium* mSilicon{nullptr};
   TGeoMedium* mAir{nullptr};
   TGeoMedium* mCarbon{nullptr};
+  TGeoMedium* mCopper{nullptr};
   void getMaterials(bool create = false);
   TGeoMedium* getMaterial(const char* matName, bool create = false);
 

Detectors/Upgrades/ITS3/simulation/src/ITS3Layer.cxx

@@ -47,6 +47,7 @@ void ITS3Layer::getMaterials(bool create)
   mSilicon = getMaterial("IT3_SI$", create);
   mAir = getMaterial("IT3_AIR$", create);
   mCarbon = getMaterial("IT3_CARBON$", create);
+  mCopper = getMaterial("IT3_COPPER$", create);
 }
 
 TGeoMedium* ITS3Layer::getMaterial(const char* matName, bool create)
@@ -276,11 +277,19 @@ void ITS3Layer::createChip()
   mChip = new TGeoVolumeAssembly(its3TGeo::getITS3ChipPattern(mNLayer));
   mChip->VisibleDaughters();
 
+  auto phiOffset = constants::segment::width / mR * o2m::Rad2Deg;
   for (unsigned int i{0}; i < constants::nSegments[mNLayer]; ++i) {
-    double phiOffset = constants::segment::width / mR * o2m::Rad2Deg;
     auto rot = new TGeoRotation("", 0, 0, phiOffset * i);
     mChip->AddNode(mSegment, i, rot);
   }
+
+  // Add metal stack positioned radially outward
+  auto zMoveMetal = new TGeoTranslation(0, 0, constants::metalstack::length / 2. - constants::segment::lec::length);
+  auto metal = new TGeoTubeSeg(mRmax, mRmax + constants::metalstack::thickness, constants::metalstack::length / 2., 0, 3.0 * phiOffset);
+  auto metalVol = new TGeoVolume(Form("metal%d", mNLayer), metal, mCopper);
+  metalVol->SetLineColor(constants::metalstack::color);
+  metalVol->RegisterYourself();
+  mChip->AddNode(metalVol, 0, zMoveMetal);
 }
 
 void ITS3Layer::createCarbonForm()