[ALICE3] TRK: simple end-of-stave cards for ML barrel (#15902)

* TOF layer enable flags and segmentation settings

* Update default values for TOF options in README

* Add specifications for eosCard in Specs.h

* ML EoS card Cu thickness parameter to TRKBaseParam

* Add createEndOfStaveCard method to TRKLayer

Added a method to create the end-of-stave card for the A-side.

* add ML end-of-stave cards to TRKLayer, adjust geometry

Updated TRKLayer to include end-of-stave card and adjust layer dimensions.

* Update z of barrel ML service disks, to give space for EoS cards

* Please consider the following formatting changes

---------

Co-authored-by: ALICE Action Bot <alibuild@cern.ch>

Author: altsybee

Detectors/Upgrades/ALICE3/IOTOF/README.md

@@ -18,10 +18,10 @@ Configurables for various sub-detectors are presented in the following Table:
 | ----------------------------- | ---------------------------------------------------------------- | -------------------------------------------------------------------------- |
 | `IOTOFBase.enableInnerTOF`    | `true` (default), `false`                                        | Enable inner TOF barrel layer                                              |
 | `IOTOFBase.enableOuterTOF`    | `true` (default), `false`                                        | Enable outer TOF barrel layer                                              |
-| `IOTOFBase.enableForwardTOF`  | `true` (default), `false`                                        | Enable forward TOF endcap                                                  |
-| `IOTOFBase.enableBackwardTOF` | `true` (default), `false`                                        | Enable backward TOF endcap                                                 |
-| `IOTOFBase.segmentedInnerTOF` | `false` (default), `true`                                        | Use segmented geometry for inner TOF                                       |
-| `IOTOFBase.segmentedOuterTOF` | `false` (default), `true`                                        | Use segmented geometry for outer TOF                                       |
+| `IOTOFBase.enableForwardTOF`  | `false` (default), `true`                                        | Enable forward TOF endcap                                                  |
+| `IOTOFBase.enableBackwardTOF` | `false` (default), `true`                                        | Enable backward TOF endcap                                                 |
+| `IOTOFBase.segmentedInnerTOF` | `true` (default), `false`                                        | Use segmented geometry for inner TOF                                       |
+| `IOTOFBase.segmentedOuterTOF` | `true` (default), `false`                                        | Use segmented geometry for outer TOF                                       |
 | `IOTOFBase.detectorPattern`   | ` ` (default), `v3b`, `v3b1a`, `v3b1b`, `v3b2a`, `v3b2b`, `v3b3` | Optional layout pattern                                                    |
 | `IOTOFBase.x2x0`              | `0.02` (default)                                                 | Chip thickness in fractions of the rad. lenght                             |
 | `IOTOFBase.sensorThickness`   | `0.0050` (default)                                               | Sensor thickness in cm, can be at maximum equivalent to the chip thickness |

Detectors/Upgrades/ALICE3/IOTOF/base/include/IOTOFBase/IOTOFBaseParam.h

@@ -47,11 +47,11 @@ struct ChipSpecificsParam : public o2::conf::ConfigurableParamPromoter<ChipSpeci
 struct IOTOFBaseParam : public o2::conf::ConfigurableParamHelper<IOTOFBaseParam> {
   bool enableInnerTOF = true;       // Enable Inner TOF layer
   bool enableOuterTOF = true;       // Enable Outer TOF layer
-  bool enableForwardTOF = true;     // Enable Forward TOF layer
-  bool enableBackwardTOF = true;    // Enable Backward TOF layer
+  bool enableForwardTOF = false;    // Enable Forward TOF layer
+  bool enableBackwardTOF = false;   // Enable Backward TOF layer
   std::string detectorPattern = ""; // Layouts of the detector
-  bool segmentedInnerTOF = false;   // If the inner TOF layer is segmented
-  bool segmentedOuterTOF = false;   // If the outer TOF layer is segmented
+  bool segmentedInnerTOF = true;    // If the inner TOF layer is segmented
+  bool segmentedOuterTOF = true;    // If the outer TOF layer is segmented
   float x2x0 = 0.02f;               // thickness expressed in radiation length, for all layers for the moment
   float sensorThickness = 0.0050f;  // thickness of the sensor in cm, for all layers for the moment, the default is set to 50 microns
 

Detectors/Upgrades/ALICE3/TRKFT3/TRK/base/include/TRKBase/Specs.h

@@ -108,6 +108,16 @@ constexpr double width{constants::moduleMLOT::width * 1}; // width of the stave
 constexpr double length{124 * cm};                                                   // length of the stave, hardcoded to fit the implemented geometry
 constexpr int nRows{static_cast<int>(width / constants::moduleMLOT::chip::pitchX)};  // number of rows in the stave
 constexpr int nCols{static_cast<int>(length / constants::moduleMLOT::chip::pitchZ)}; // number of columns in the stave
+
+namespace eosCard                           // end-of-stave readout card, one per ML stave, A-side (+z) only,
+{                                           // placed in front of the TRK_MIDBARCONN_DISK (fibre, power, ...)
+constexpr double length{90 * mm};           // z-extent (fits the gap to the conn disk)
+constexpr double width{50 * mm};            // phi-extent
+constexpr double thickness{1.5 * mm};       // r-extent, FR4 + copper planes
+constexpr int nCopperLayers{4};             // copper planes, spread over the thickness
+constexpr double copperThickness{122 * mu}; // per copper plane; default of TRKBase.mlEosCardCuThickness
+constexpr double zGap{0.1 * mm};            // z-clearance from the last module / stave end
+} // namespace eosCard
 } // namespace ML
 
 namespace OT

Detectors/Upgrades/ALICE3/TRKFT3/TRK/base/include/TRKBase/TRKBaseParam.h

@@ -45,6 +45,7 @@ struct TRKBaseParam : public o2::conf::ConfigurableParamHelper<TRKBaseParam> {
   float serviceTubeX0 = 0.02f;                                          // X0 Al2O3
   float otBarrelWallThickness = 0.2f;                                   // cm, carbon fibre separation walls of the OT quarter barrels, 0 disables them
   float otEosCardCuThickness = constants::OT::eosCard::copperThickness; // cm, copper per plane in the OT end-of-stave card; drives the card x/X0
+  float mlEosCardCuThickness = constants::ML::eosCard::copperThickness; // cm, copper per plane in the ML end-of-stave card; drives the card x/X0
   bool irisOpen = false;
   bool includeLowServices = false;
 
@@ -76,4 +77,4 @@ struct TRKBaseParam : public o2::conf::ConfigurableParamHelper<TRKBaseParam> {
 } // end namespace trk
 } // end namespace o2
 
-#endif
+#endif

Detectors/Upgrades/ALICE3/TRKFT3/TRK/simulation/include/TRKSimulation/TRKLayer.h

@@ -118,6 +118,8 @@ class TRKMLLayer : public TRKSegmentedLayer
   void createLayer(TGeoVolume* motherVolume) override;
 
  private:
+  TGeoVolume* createEndOfStaveCard(); // A-side (+z) end-of-stave card, in front of the conn disk
+
   float mStaggerOffset;
 
   static constexpr double sStaveWidth = constants::ML::width;

Detectors/Upgrades/ALICE3/TRKFT3/TRK/simulation/src/TRKLayer.cxx

@@ -247,10 +247,9 @@ TRKMLLayer::TRKMLLayer(int layerNumber, std::string layerName, float rInn, float
 
 TGeoVolume* TRKMLLayer::createStave()
 {
-  TGeoMedium* medAir = gGeoManager->GetMedium("TRK_AIR$");
+  // Assembly (not a solid box) so the end-of-stave card can extend past the module envelope.
   std::string staveName = GeometryTGeo::getTRKStavePattern() + std::to_string(mLayerNumber);
-  TGeoShape* stave = new TGeoBBox(sStaveWidth / 2, mChipThickness / 2, mLength / 2);
-  TGeoVolume* staveVol = new TGeoVolume(staveName.c_str(), stave, medAir);
+  TGeoVolume* staveVol = new TGeoVolumeAssembly(staveName.c_str());
   staveVol->SetLineColor(kYellow);
 
   for (int iModule = 0; iModule < mNumberOfModules; iModule++) {
@@ -262,17 +261,58 @@ TGeoVolume* TRKMLLayer::createStave()
     staveVol->AddNode(moduleVol, iModule, trans);
   }
 
+  // End-of-stave card on the A-side (+z) only, just past the stave end and in front of the
+  // TRK_MIDBARCONN_DISK. Local frame: x = phi (width), y = radial (thickness), z = length.
+  TGeoCombiTrans* tCard = new TGeoCombiTrans();
+  tCard->SetTranslation(0, 0, mLength / 2 + constants::ML::eosCard::zGap + constants::ML::eosCard::length / 2);
+  staveVol->AddNode(createEndOfStaveCard(), 0, tCard);
+
   return staveVol;
 }
 
+TGeoVolume* TRKMLLayer::createEndOfStaveCard()
+{
+  // FR4 board carrying evenly spaced copper planes; same construction as the OT card, with its
+  // own constants::ML::eosCard dimensions and a configurable copper thickness (TRKBase.mlEosCardCuThickness),
+  // which displaces FR4 inside the fixed envelope and sets the card x/X0.
+  TGeoMedium* medFR4 = gGeoManager->GetMedium("TRK_FR4$");
+  TGeoMedium* medCu = gGeoManager->GetMedium("TRK_COPPER$");
+  const std::string name = GeometryTGeo::getTRKStavePattern() + std::to_string(mLayerNumber) + "_EOSCard";
+
+  TGeoShape* board = new TGeoBBox(constants::ML::eosCard::width / 2, constants::ML::eosCard::thickness / 2, constants::ML::eosCard::length / 2);
+  TGeoVolume* cardVol = new TGeoVolume(name.c_str(), board, medFR4);
+  cardVol->SetLineColor(kGreen + 3);
+
+  const double cuThickness = TRKBaseParam::Instance().mlEosCardCuThickness;
+  const int nPlanes = constants::ML::eosCard::nCopperLayers;
+  if (cuThickness * nPlanes >= constants::ML::eosCard::thickness) {
+    LOGP(fatal, "TRKBase.mlEosCardCuThickness = {} cm x {} planes does not fit in the {} cm ML end-of-stave card",
+         cuThickness, nPlanes, constants::ML::eosCard::thickness);
+  }
+  TGeoShape* plane = new TGeoBBox(constants::ML::eosCard::width / 2, cuThickness / 2, constants::ML::eosCard::length / 2);
+  TGeoVolume* planeVol = new TGeoVolume((name + "_Cu").c_str(), plane, medCu);
+  planeVol->SetLineColor(kOrange + 7);
+
+  // Evenly spaced, the outermost two flush with the board surfaces.
+  const double span = constants::ML::eosCard::thickness - cuThickness;
+  for (int iPlane = 0; iPlane < nPlanes; iPlane++) {
+    const double y = (nPlanes > 1) ? -span / 2 + iPlane * span / (nPlanes - 1) : 0.;
+    cardVol->AddNode(planeVol, iPlane, new TGeoTranslation(0, y, 0));
+  }
+
+  return cardVol;
+}
+
 void TRKMLLayer::createLayer(TGeoVolume* motherVolume)
 {
   // Retrieve exact bounding boundaries and create the logical container volume
   auto [rMin, rMax] = getBoundingRadii(sStaveWidth);
 
   TGeoMedium* medAir = gGeoManager->GetMedium("TRK_AIR$");
   // TGeoTube* layer = new TGeoTube(mInnerRadius - 0.333 * sLogicalVolumeThickness, mInnerRadius + 0.667 * sLogicalVolumeThickness, mLength / 2);
-  TGeoTube* layer = new TGeoTube(rMin, rMax, mLength / 2);
+  // Extend the z half-length so the A-side end-of-stave card (past mLength/2) stays inside the layer.
+  const double halfLengthZ = mLength / 2 + constants::ML::eosCard::zGap + constants::ML::eosCard::length;
+  TGeoTube* layer = new TGeoTube(rMin, rMax, halfLengthZ);
   TGeoVolume* layerVol = new TGeoVolume(mLayerName.c_str(), layer, medAir);
   layerVol->SetLineColor(kYellow);
 

Detectors/Upgrades/ALICE3/TRKFT3/TRK/simulation/src/TRKServices.cxx

@@ -630,7 +630,7 @@ void TRKServices::createMLServicesPeacock(TGeoVolume* motherVolume)
 
   // Get geometry information from TRK which is already present
   float rMinMiddleServices = 38.0f;                       // cm, start radius of the ML services = maximum radius allowed for sensors (35 cm), plus some margin for disk paving with modules
-  const float zMiddleServicesBarrel = 64.5f;              // cm, z position of the first barrel ML service disk
+  const float zMiddleServicesBarrel = 74.0f;              // cm, z position of the first barrel ML service disk
   const float zMiddleServicesBarrelFwdConnection = 143.f; // cm, z position of barrel to forward connection services
   const float zLengthCylinderMiddleServicesBarrel = zMiddleServicesBarrelFwdConnection - zMiddleServicesBarrel;