[FT3] Modular structure for OT disks - first version of modules structure with dynamic disks paving for ALICE 3 sensors and initial material estimations

Rita Sadek · Rita Sadek · commit 292175e83077 · 2025-11-13T09:51:03.000-08:00
diff --git a/Detectors/Upgrades/ALICE3/FT3/simulation/CMakeLists.txt b/Detectors/Upgrades/ALICE3/FT3/simulation/CMakeLists.txt
@@ -10,14 +10,18 @@
 # or submit itself to any jurisdiction.
 
 o2_add_library(FT3Simulation
-               SOURCES src/FT3Layer.cxx
+               SOURCES
+                       src/FT3Module.cxx
+                       src/FT3Layer.cxx
                        src/Detector.cxx
                PUBLIC_LINK_LIBRARIES O2::FT3Base
                                      O2::ITSMFTSimulation
                                      ROOT::Physics)
 
 o2_target_root_dictionary(FT3Simulation
-                          HEADERS include/FT3Simulation/Detector.h
+                          HEADERS
+                                  include/FT3Simulation/FT3Module.h
+                                  include/FT3Simulation/Detector.h
                                   include/FT3Simulation/FT3Layer.h)
 
 o2_data_file(COPY data  DESTINATION Detectors/FT3/simulation)
diff --git a/Detectors/Upgrades/ALICE3/FT3/simulation/include/FT3Simulation/FT3Layer.h b/Detectors/Upgrades/ALICE3/FT3/simulation/include/FT3Simulation/FT3Layer.h
@@ -18,6 +18,7 @@
 #include <TGeoManager.h>            // for gGeoManager
 #include "Rtypes.h"                 // for Double_t, Int_t, Bool_t, etc
 #include "FT3Simulation/Detector.h" // for Detector, Detector::Model
+#include "FT3Simulation/FT3Module.h"
 
 class TGeoVolume;
 
@@ -57,6 +58,24 @@ class FT3Layer : public TObject
   /// \param motherVolume the TGeoVolume owing the volume structure
   virtual void createLayer(TGeoVolume* motherVolume);
 
+  static void initialize_mat();
+
+  // create layer for disk support
+  void createSeparationLayer(TGeoVolume* motherVolume, const std::string& separationLayerName);
+  void createSeparationLayer_waterCooling(TGeoVolume* motherVolume, const std::string& separationLayerName);
+
+  static TGeoMaterial* carbonFiberMat;
+  static TGeoMedium* medCarbonFiber;
+
+  static TGeoMaterial* kaptonMat;
+  static TGeoMedium* kaptonMed;
+
+  static TGeoMaterial* waterMat;
+  static TGeoMedium* waterMed;
+
+  static TGeoMaterial* foamMat;
+  static TGeoMedium* medFoam;
+
  private:
   Int_t mLayerNumber = -1; ///< Current layer number
   Int_t mDirection;        ///< Layer direction 0=Forward 1 = Backward
diff --git a/Detectors/Upgrades/ALICE3/FT3/simulation/include/FT3Simulation/FT3Module.h b/Detectors/Upgrades/ALICE3/FT3/simulation/include/FT3Simulation/FT3Module.h
@@ -0,0 +1,45 @@
+// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
+// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
+// All rights not expressly granted are reserved.
+//
+// This software is distributed under the terms of the GNU General Public
+// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
+//
+// In applying this license CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+/// \file FT3Module.h
+/// \brief Definition of the FT3Module class
+
+#ifndef FT3MODULE_H
+#define FT3MODULE_H
+
+#include <TGeoVolume.h>
+#include <string>
+
+class FT3Module
+{
+
+ public:
+  static void initialize_materials();
+  static TGeoMaterial* siliconMat;
+  static TGeoMedium* siliconMed;
+  static TGeoMaterial* copperMat;
+  static TGeoMedium* copperMed;
+  static TGeoMaterial* kaptonMat;
+  static TGeoMedium* kaptonMed;
+  static TGeoMaterial* epoxyMat;
+  static TGeoMedium* epoxyMed;
+  static TGeoMaterial* AluminumMat;
+  static TGeoMedium* AluminumMed;
+
+  const char* mDetName;
+
+  static void createModule(double mZ, int layerNumber, int direction, double Rin, double Rout, double overlap, const std::string& face, const std::string& layout_type, TGeoVolume* motherVolume);
+
+ private:
+  static void create_layout(double mZ, int layerNumber, int direction, double Rin, double Rout, double overlap, const std::string& face, const std::string& layout_type, TGeoVolume* motherVolume);
+};
+
+#endif // FT3MODULE_H
diff --git a/Detectors/Upgrades/ALICE3/FT3/simulation/src/Detector.cxx b/Detectors/Upgrades/ALICE3/FT3/simulation/src/Detector.cxx
@@ -40,6 +40,8 @@
 
 #include <cstdio> // for NULL, snprintf
 
+#define MAX_SENSORS 2000
+
 class FairModule;
 
 class TGeoMedium;
@@ -729,9 +731,23 @@ void Detector::defineSensitiveVolumes()
     for (int direction : {0, 1}) {
       for (int iLayer = 0; iLayer < mNumberOfLayers; iLayer++) {
         volumeName = o2::ft3::GeometryTGeo::getFT3SensorPattern() + std::to_string(iLayer);
-        v = geoManager->GetVolume(Form("%s_%d_%d", GeometryTGeo::getFT3SensorPattern(), direction, iLayer));
-        LOG(info) << "Adding FT3 Sensitive Volume => " << v->GetName();
-        AddSensitiveVolume(v);
+        if (iLayer < 3) { // ML disks
+          v = geoManager->GetVolume(Form("%s_%d_%d", GeometryTGeo::getFT3SensorPattern(), direction, iLayer));
+          AddSensitiveVolume(v);
+        } else { // OT disks
+          for (int sensor_count = 0; sensor_count < MAX_SENSORS; ++sensor_count) {
+            std::string sensor_name_front = "FT3sensor_front_" + std::to_string(iLayer) + "_" + std::to_string(direction) + "_" + std::to_string(sensor_count);
+            std::string sensor_name_back = "FT3sensor_back_" + std::to_string(iLayer) + "_" + std::to_string(direction) + "_" + std::to_string(sensor_count);
+            v = geoManager->GetVolume(sensor_name_front.c_str());
+            if (v) {
+              AddSensitiveVolume(v);
+            }
+            v = geoManager->GetVolume(sensor_name_back.c_str());
+            if (v) {
+              AddSensitiveVolume(v);
+            }
+          }
+        }
       }
     }
   }
diff --git a/Detectors/Upgrades/ALICE3/FT3/simulation/src/FT3Layer.cxx b/Detectors/Upgrades/ALICE3/FT3/simulation/src/FT3Layer.cxx
@@ -28,7 +28,10 @@
 #include "TMathBase.h"          // for Abs
 #include <TMath.h>              // for Sin, RadToDeg, DegToRad, Cos, Tan, etc
 
+#include <TGeoBBox.h>
+#include <string>
 #include <cstdio> // for snprintf
+#include <cmath>
 
 class TGeoMedium;
 
@@ -40,6 +43,18 @@ ClassImp(FT3Layer);
 
 FT3Layer::~FT3Layer() = default;
 
+TGeoMaterial* FT3Layer::carbonFiberMat = nullptr;
+TGeoMedium* FT3Layer::medCarbonFiber = nullptr;
+
+TGeoMaterial* FT3Layer::kaptonMat = nullptr;
+TGeoMedium* FT3Layer::kaptonMed = nullptr;
+
+TGeoMaterial* FT3Layer::waterMat = nullptr;
+TGeoMedium* FT3Layer::waterMed = nullptr;
+
+TGeoMaterial* FT3Layer::foamMat = nullptr;
+TGeoMedium* FT3Layer::medFoam = nullptr;
+
 FT3Layer::FT3Layer(Int_t layerDirection, Int_t layerNumber, std::string layerName, Float_t z, Float_t rIn, Float_t rOut, Float_t Layerx2X0)
 {
   // Creates a simple parametrized EndCap layer covering the given
@@ -59,10 +74,156 @@ FT3Layer::FT3Layer(Int_t layerDirection, Int_t layerNumber, std::string layerNam
   LOG(info) << "   Layer z = " << mZ << " ; R_in = " << mInnerRadius << " ; R_out = " << mOuterRadius << " ; x2X0 = " << mx2X0 << " ; ChipThickness = " << mChipThickness;
 }
 
+void FT3Layer::initialize_mat()
+{
+
+  if (carbonFiberMat)
+    return;
+
+  carbonFiberMat = new TGeoMaterial("CarbonFiber", 12.0, 6.0, 1.6);
+  medCarbonFiber = new TGeoMedium("CarbonFiber", 1, carbonFiberMat);
+
+  auto* itsC = new TGeoElement("FT3_C", "Carbon", 6, 12.0107);
+
+  auto* itsFoam = new TGeoMixture("FT3_Foam", 1);
+  itsFoam->AddElement(itsC, 1);
+  itsFoam->SetDensity(0.17);
+
+  medFoam = new TGeoMedium("FT3_Foam", 1, itsFoam);
+  foamMat = medFoam->GetMaterial();
+
+  kaptonMat = new TGeoMaterial("Kapton (cooling pipe)", 13.84, 6.88, 1.346);
+  kaptonMed = new TGeoMedium("Kapton (cooling pipe)", 1, kaptonMat);
+
+  waterMat = new TGeoMaterial("Water", 18.01528, 8.0, 1.064);
+  waterMed = new TGeoMedium("Water", 2, waterMat);
+}
+
+static double y_circle(double x, double radius)
+{
+  return (x * x < radius * radius) ? std::sqrt(radius * radius - x * x) : 0;
+}
+
+void FT3Layer::createSeparationLayer_waterCooling(TGeoVolume* motherVolume, const std::string& separationLayerName)
+{
+
+  FT3Layer::initialize_mat();
+
+  double carbonFiberThickness = 0.01;
+  double foamSpacingThickness = 0.5;
+
+  TGeoTube* carbonFiberLayer = new TGeoTube(mInnerRadius, mOuterRadius, carbonFiberThickness / 2);
+
+  // volumes
+  TGeoVolume* carbonFiberLayerVol1 = new TGeoVolume((separationLayerName + "_CarbonFiber1").c_str(), carbonFiberLayer, medCarbonFiber);
+  TGeoVolume* carbonFiberLayerVol2 = new TGeoVolume((separationLayerName + "_CarbonFiber2").c_str(), carbonFiberLayer, medCarbonFiber);
+
+  carbonFiberLayerVol1->SetLineColor(kGray + 2);
+  carbonFiberLayerVol2->SetLineColor(kGray + 2);
+
+  double zSeparation = foamSpacingThickness / 2.0 + carbonFiberThickness / 2.0;
+
+  motherVolume->AddNode(carbonFiberLayerVol1, 1, new TGeoTranslation(0, 0, mZ - zSeparation));
+  motherVolume->AddNode(carbonFiberLayerVol2, 1, new TGeoTranslation(0, 0, mZ + zSeparation));
+
+  double pipeOuterRadius = 0.20;
+  double kaptonThickness = 0.0025;
+  double pipeInnerRadius = pipeOuterRadius - kaptonThickness;
+  double pipeMaxLength = mOuterRadius * 2.0;
+
+  int name_it = 0;
+
+  // positions of the pipes depending on the overlap of the sensors inactive regions: (ALICE 3 dimensions)
+  // partial:
+  //  std::vector<double> X_pos = {-63.2, -58.4, -53.6, -48.8, -44.0, -39.199999999999996, -34.4, -29.599999999999994, -24.799999999999997, -19.999999999999993, -15.199999999999998, -10.399999999999993, -5.599999999999998, -0.7999999999999936, 4.000000000000002, 8.800000000000006, 13.600000000000001, 18.400000000000006, 23.200000000000003, 28.000000000000007, 32.800000000000004, 37.60000000000001, 42.400000000000006, 47.20000000000001, 52.00000000000001, 56.80000000000001, 61.60000000000001, 66.4};
+  // complete:
+  // std::vector<double> X_pos = {-63.4, -58.8, -54.199999999999996, -49.599999999999994, -44.99999999999999, -40.39999999999999, -35.79999999999999, -31.199999999999992, -26.59999999999999, -21.999999999999993, -17.39999999999999, -12.799999999999994, -8.199999999999992, -3.5999999999999934, 1.000000000000008, 5.600000000000007, 10.200000000000008, 14.800000000000008, 19.40000000000001, 24.000000000000007, 28.60000000000001, 33.20000000000001, 37.80000000000001, 42.40000000000001, 47.000000000000014, 51.600000000000016, 56.20000000000002, 60.80000000000002, 65.40000000000002};
+  std::vector<double> X_pos = {-62.3168, -57.9836, -53.650400000000005, -49.317200000000014, -44.984000000000016, -40.65080000000002, -36.31760000000002, -31.984400000000026, -27.65120000000003, -23.318000000000037, -18.98480000000004, -14.651600000000043, -10.318400000000047, -5.98520000000005, -1.6520000000000519, 2.6811999999999445, 7.014399999999941, 11.347599999999936, 15.680799999999934, 20.01399999999993, 24.347199999999926, 28.68039999999992, 33.013599999999926, 37.34679999999992, 41.980000000000004, 46.613200000000006, 51.246399999999994, 55.87960000000001, 60.5128};
+
+  for (double xPos : X_pos) {
+
+    double pipeLength = pipeMaxLength;
+    double yMax = 0.0;
+
+    TGeoRotation* rotation = new TGeoRotation();
+    rotation->RotateX(90);
+
+    if (std::abs(xPos) < mInnerRadius) {
+      double yInner = std::abs(y_circle(xPos, mInnerRadius));
+      double yOuter = std::abs(y_circle(xPos, mOuterRadius));
+
+      yMax = 2 * yOuter;
+      pipeLength = yMax;
+
+      double positiveYLength = yOuter - yInner;
+
+      TGeoVolume* kaptonPipePos = new TGeoVolume((separationLayerName + "_KaptonPipePos_" + std::to_string(name_it)).c_str(), new TGeoTube(pipeInnerRadius, pipeOuterRadius, positiveYLength / 2), kaptonMed);
+      kaptonPipePos->SetLineColor(kGray);
+      TGeoVolume* waterVolumePos = new TGeoVolume((separationLayerName + "_WaterVolumePos_" + std::to_string(name_it)).c_str(), new TGeoTube(0.0, pipeInnerRadius, positiveYLength / 2), waterMed);
+      waterVolumePos->SetLineColor(kBlue);
+
+      motherVolume->AddNode(waterVolumePos, 1, new TGeoCombiTrans(xPos, (yInner + yOuter) / 2.0, mZ, rotation));
+
+      TGeoVolume* kaptonPipeNeg = new TGeoVolume((separationLayerName + "_KaptonPipeNeg_" + std::to_string(name_it)).c_str(), new TGeoTube(pipeInnerRadius, pipeOuterRadius, positiveYLength / 2), kaptonMed);
+      kaptonPipeNeg->SetLineColor(kGray);
+      TGeoVolume* waterVolumeNeg = new TGeoVolume((separationLayerName + "_WaterVolumeNeg_" + std::to_string(name_it)).c_str(), new TGeoTube(0.0, pipeInnerRadius, positiveYLength / 2), waterMed);
+      waterVolumeNeg->SetLineColor(kBlue);
+
+      motherVolume->AddNode(waterVolumeNeg, 1, new TGeoCombiTrans(xPos, -(yInner + yOuter) / 2.0, mZ, rotation));
+
+      motherVolume->AddNode(kaptonPipePos, 1, new TGeoCombiTrans(xPos, (yInner + yOuter) / 2.0, mZ, rotation));
+      motherVolume->AddNode(kaptonPipeNeg, 1, new TGeoCombiTrans(xPos, -(yInner + yOuter) / 2.0, mZ, rotation));
+
+    } else {
+
+      double yOuter = std::abs(y_circle(xPos, mOuterRadius));
+      yMax = 2 * yOuter;
+      pipeLength = yMax;
+
+      TGeoVolume* kaptonPipe = new TGeoVolume((separationLayerName + "_KaptonPipe_" + std::to_string(name_it)).c_str(), new TGeoTube(pipeInnerRadius, pipeOuterRadius, pipeLength / 2), kaptonMed);
+      kaptonPipe->SetLineColor(kGray);
+      TGeoVolume* waterVolume = new TGeoVolume((separationLayerName + "_WaterVolume_" + std::to_string(name_it)).c_str(), new TGeoTube(0.0, pipeInnerRadius, pipeLength / 2), waterMed);
+      waterVolume->SetLineColor(kBlue);
+
+      motherVolume->AddNode(waterVolume, 1, new TGeoCombiTrans(xPos, 0, mZ, rotation));
+      motherVolume->AddNode(kaptonPipe, 1, new TGeoCombiTrans(xPos, 0, mZ, rotation));
+    }
+
+    name_it++;
+  }
+}
+
+void FT3Layer::createSeparationLayer(TGeoVolume* motherVolume, const std::string& separationLayerName)
+{
+
+  FT3Layer::initialize_mat();
+
+  double carbonFiberThickness = 0.01;
+  double foamSpacingThickness = 1.0;
+
+  TGeoTube* carbonFiberLayer = new TGeoTube(mInnerRadius, mOuterRadius, carbonFiberThickness / 2);
+  TGeoTube* foamLayer = new TGeoTube(mInnerRadius, mOuterRadius, foamSpacingThickness / 2);
+
+  // volumes
+  TGeoVolume* carbonFiberLayerVol1 = new TGeoVolume((separationLayerName + "_CarbonFiber1").c_str(), carbonFiberLayer, medCarbonFiber);
+  TGeoVolume* foamLayerVol = new TGeoVolume((separationLayerName + "_Foam").c_str(), foamLayer, medFoam);
+  TGeoVolume* carbonFiberLayerVol2 = new TGeoVolume((separationLayerName + "_CarbonFiber2").c_str(), carbonFiberLayer, medCarbonFiber);
+
+  carbonFiberLayerVol1->SetLineColor(kGray + 2);
+  foamLayerVol->SetLineColor(kBlack);
+  foamLayerVol->SetFillColorAlpha(kBlack, 1.0);
+  carbonFiberLayerVol2->SetLineColor(kGray + 2);
+
+  double zSeparation = foamSpacingThickness / 2.0 + carbonFiberThickness / 2.0;
+
+  motherVolume->AddNode(carbonFiberLayerVol1, 1, new TGeoTranslation(0, 0, mZ - zSeparation));
+  motherVolume->AddNode(foamLayerVol, 1, new TGeoTranslation(0, 0, mZ));
+  motherVolume->AddNode(carbonFiberLayerVol2, 1, new TGeoTranslation(0, 0, mZ + zSeparation));
+}
+
 void FT3Layer::createLayer(TGeoVolume* motherVolume)
 {
-  if (mLayerNumber >= 0) {
-    // Create tube, set sensitive volume, add to mother volume
+  if (mLayerNumber >= 0 && mLayerNumber < 3) {
 
     std::string chipName = o2::ft3::GeometryTGeo::getFT3ChipPattern() + std::to_string(mLayerNumber),
                 sensName = Form("%s_%d_%d", GeometryTGeo::getFT3SensorPattern(), mDirection, mLayerNumber);
@@ -93,6 +254,21 @@ void FT3Layer::createLayer(TGeoVolume* motherVolume)
     LOG(info) << "Inserting " << layerVol->GetName() << " inside " << motherVolume->GetName();
     motherVolume->AddNode(layerVol, 1, FwdDiskCombiTrans);
 
-    return;
+  } else if (mLayerNumber >= 3) {
+
+    FT3Module module;
+    std::string frontLayerName = "FT3Layer" + std::to_string(mLayerNumber) + "_Front";
+    std::string backLayerName = "FT3Layer" + std::to_string(mLayerNumber) + "_Back";
+    std::string separationLayerName = "SeparationLayer" + std::to_string(mLayerNumber);
+
+    TGeoVolume* separationLayerVol = new TGeoVolume(separationLayerName.c_str(), new TGeoTube(mInnerRadius, mOuterRadius, 2.5), gGeoManager->GetMedium("FT3_AIR$"));
+    separationLayerVol->SetLineColor(kGray);
+
+    // create disk faces
+    module.createModule(mZ, mLayerNumber, mDirection, mInnerRadius, mOuterRadius, 0., "front", "rectangular", motherVolume);
+    module.createModule(mZ, mLayerNumber, mDirection, mInnerRadius, mOuterRadius, 0., "back", "rectangular", motherVolume);
+
+    // createSeparationLayer_waterCooling(motherVolume, separationLayerName);
+    createSeparationLayer(motherVolume, separationLayerName);
   }
 }
diff --git a/Detectors/Upgrades/ALICE3/FT3/simulation/src/FT3Module.cxx b/Detectors/Upgrades/ALICE3/FT3/simulation/src/FT3Module.cxx
