TRTDetectorFactory_Full: changed the way the central barrel is constructed

The goal of this exercise is to test a different approach to the construction of the central barrel. If this mechanism proves to be successful, then a similar strategy will be applied to endcaps, and finally, it will also be implemented in the standalone TRT GeoModel plugin code in the GeoModelATLAS repository.

In the current implementation, we construct one instance of the barrel radiator Serial Transformer per layer for each potential straw material - Xenon, Argon, and Krypton - and then reuse it as many times as needed when constructing the barrel. In the new approach, we don't share Serial Transformers. Instead for each radiator, a new Transformer is created. The memory overhead of the new implementation is negligible (at the level of 0.5% wrt the current one). OTOH, after applying this strategy to the standalone implementation it will be possible to patch the materials of individual modules after reading the persistent description from SQLite.

CC @cgrefe

InnerDetector/InDetDetDescr/TRT_GeoModel/src/TRTDetectorFactory_Full.cxx

@@ -663,28 +663,13 @@ void TRTDetectorFactory_Full::create(GeoPhysVol *world)
 
     pCoolingTube->add(pCoolingFluid);
 
-    double activeGasZPositionNormalStraws, activeGasZPositionStrawsWithLargeDeadRegion;
-	//AALONSO, create the Argon Straws
-    GeoNodePtr<GeoPhysVol> pHoleForMixedStrawAR;
-    GeoNodePtr<GeoPhysVol> pHoleForMixedStrawWithLargeDeadRegionAR;
-    if (m_doArgon)
-      {
-      pHoleForMixedStrawAR                    = makeStraw(activeGasZPositionNormalStraws, false, GM_ARGON);
-      pHoleForMixedStrawWithLargeDeadRegionAR = makeStraw(activeGasZPositionStrawsWithLargeDeadRegion,true, GM_ARGON);
-      }
-    // and krypton straws
-    GeoNodePtr<GeoPhysVol> pHoleForMixedStrawKR;
-    GeoNodePtr<GeoPhysVol> pHoleForMixedStrawWithLargeDeadRegionKR;
-    if (m_doKrypton)
-      {
-      pHoleForMixedStrawKR                    = makeStraw(activeGasZPositionNormalStraws, false, GM_KRYPTON);
-      pHoleForMixedStrawWithLargeDeadRegionKR = makeStraw(activeGasZPositionStrawsWithLargeDeadRegion,true, GM_KRYPTON);
-      }
+    double lengthOfInnerDeadRegion= m_data->lengthOfDeadRegion;
+    double lengthOfActiveGas = (m_data->barrelLengthOfStraw-m_data->barrelLengthOfTwister)/2.0 - m_data->lengthOfDeadRegion - lengthOfInnerDeadRegion;
+    double activeGasZPositionNormalStraws = (lengthOfActiveGas + m_data->barrelLengthOfTwister) / 2. + lengthOfInnerDeadRegion;
 
-    // The barrel straw (including the "hole" in the radiator around it):
-    GeoNodePtr<GeoPhysVol> pHoleForMixedStraw = makeStraw(activeGasZPositionNormalStraws);
-    // The straws in the inner layers of module A have a large dead region, and are thus different.
-    GeoNodePtr<GeoPhysVol> pHoleForMixedStrawWithLargeDeadRegion = makeStraw(activeGasZPositionStrawsWithLargeDeadRegion,true);
+    lengthOfInnerDeadRegion = m_data->barrelLengthOfLargeDeadRegion;
+    lengthOfActiveGas = (m_data->barrelLengthOfStraw-m_data->barrelLengthOfTwister)/2.0 - m_data->lengthOfDeadRegion - lengthOfInnerDeadRegion;
+    double activeGasZPositionStrawsWithLargeDeadRegion = (lengthOfActiveGas + m_data->barrelLengthOfTwister) / 2. + lengthOfInnerDeadRegion;
   
     // The modules themselves.
     for (size_t iABC=0;iABC<m_data->nBarrelRings;iABC++) {
@@ -737,37 +722,14 @@ void TRTDetectorFactory_Full::create(GeoPhysVol *world)
       if (!radMat) radMat = m_materialManager->getMaterial("trt::FibreRadiator");
 
       lRad = new GeoLogVol(radName, sRad, radMat);
-      GeoNodePtr<GeoPhysVol> pRad(new GeoPhysVol(lRad));
-      GeoNodePtr<GeoPhysVol> pRadAR(m_doArgon   ? new GeoPhysVol(lRad) : nullptr );
-      GeoNodePtr<GeoPhysVol> pRadKR(m_doKrypton ? new GeoPhysVol(lRad) : nullptr);
 
       //---------------------------------------------------------------------------------------------------------------
       // Place the cooling tubes in the Radiator
-
       GeoTransform  *xCool1 = new GeoTransform(shellPosition.inverse()
 					       *GeoTrf::Translate3D(m_data->barrelXOfCoolingTube[iABC][0],m_data->barrelYOfCoolingTube[iABC][0],0));
       GeoTransform  *xCool2 = new GeoTransform(shellPosition.inverse()
 					       *GeoTrf::Translate3D(m_data->barrelXOfCoolingTube[iABC][1],m_data->barrelYOfCoolingTube[iABC][1],0));
 
-      pRad->add(xCool1);
-      pRad->add(pCoolingTube);
-      pRad->add(xCool2);
-      pRad->add(pCoolingTube);
-      if (m_doArgon)
-        {
-        pRadAR->add(xCool1);
-        pRadAR->add(pCoolingTube);
-        pRadAR->add(xCool2);
-        pRadAR->add(pCoolingTube);
-        }
-      if (m_doKrypton)
-        {
-        pRadKR->add(xCool1);
-        pRadKR->add(pCoolingTube);
-        pRadKR->add(xCool2);
-        pRadKR->add(pCoolingTube);
-        }
-
       //----------------------------------------------------------------------------------------------------------------
       // Parameterize all of the straws and put them within the radiator.
 
@@ -840,46 +802,7 @@ void TRTDetectorFactory_Full::create(GeoPhysVol *world)
       } else {
 	m_detectorManager->setBarrelTransformField(iABC,tx2.clone());
       }
-	//AALONSO
-      GeoSerialTransformer *serialTransformer = nullptr;
-      GeoSerialTransformer *serialTransformerAR = nullptr;  //Ruslan
-      GeoSerialTransformer *serialTransformerKR = nullptr;  //Artem
-
-      serialTransformer     = new GeoSerialTransformer(pHoleForMixedStraw,   &tx2, m_data->barrelNumberOfStrawsInModule[iABC]-nStrawsWithLargeDeadRegion);
-      if (m_doArgon) {
-        serialTransformerAR = new GeoSerialTransformer(pHoleForMixedStrawAR, &tx2, m_data->barrelNumberOfStrawsInModule[iABC]-nStrawsWithLargeDeadRegion);
-      }
-      if (m_doKrypton) {
-        serialTransformerKR = new GeoSerialTransformer(pHoleForMixedStrawKR, &tx2, m_data->barrelNumberOfStrawsInModule[iABC]-nStrawsWithLargeDeadRegion);
-      }
-
-
-      GeoNodePtr<GeoSerialTransformer> serialTransformerDead;
-      GeoNodePtr<GeoSerialTransformer> serialTransformerDeadAR;
-      GeoNodePtr<GeoSerialTransformer> serialTransformerDeadKR;
-      serialTransformerDead     = new GeoSerialTransformer(pHoleForMixedStrawWithLargeDeadRegion  , &tx2Dead,
-								      nStrawsWithLargeDeadRegion);
-      if (m_doArgon)
-        serialTransformerDeadAR = new GeoSerialTransformer(pHoleForMixedStrawWithLargeDeadRegionAR, &tx2Dead,
-                      nStrawsWithLargeDeadRegion);
-      if (m_doKrypton)
-        serialTransformerDeadKR = new GeoSerialTransformer(pHoleForMixedStrawWithLargeDeadRegionKR, &tx2Dead,
-                      nStrawsWithLargeDeadRegion);
-
-     
       
-      pRad->add(new GeoSerialIdentifier(0));
-      if (m_doArgon  ) pRadAR->add(new GeoSerialIdentifier(0));
-      if (m_doKrypton) pRadKR->add(new GeoSerialIdentifier(0));
-      if (iABC==0) {
-        pRad->add(serialTransformerDead);
-        if (m_doArgon  ) pRadAR->add(serialTransformerDeadAR);
-        if (m_doKrypton) pRadKR->add(serialTransformerDeadKR);
-      }
-      pRad->add(serialTransformer);
-      if (m_doArgon  ) pRadAR->add(serialTransformerAR);
-      if (m_doKrypton) pRadKR->add(serialTransformerKR);
-
       // Adds one straw from each layer (reformulate..) (should be done via m_data from database)
       double oldx=-999*GeoModelKernelUnits::cm, oldz=-999*GeoModelKernelUnits::cm;
       unsigned int c=0;
@@ -961,24 +884,36 @@ void TRTDetectorFactory_Full::create(GeoPhysVol *world)
 	if (m_strawsvcavailable && (m_doArgon || m_doKrypton)) strawStatusHT = m_sumTool->getStatusHT(TRT_Identifier);
 	ActiveGasMixture agm = DecideGasMixture(strawStatusHT);
 
-	// Ruslan: insert radiators with Ar-straws
-	// Artem: same for Kr
+	// Make a radiator
+	GeoNodePtr<GeoPhysVol> pRad(new GeoPhysVol(lRad));
+	pRad->add(xCool1);
+        pRad->add(pCoolingTube);
+        pRad->add(xCool2);
+        pRad->add(pCoolingTube);
+	pRad->add(new GeoSerialIdentifier(0));
+
+	GeoNodePtr<GeoPhysVol> pHoleForMixedStraw;
+	GeoNodePtr<GeoPhysVol> pHoleForMixedStrawWithLargeDeadRegion;
+
 	switch (agm)
 	{
 	case GM_ARGON:
 	  ATH_MSG_DEBUG( "Marking Argon straws from /TRT/Cond/StatusHT:\t"
 			 << idHelper->print_to_string(TRT_Identifier));
-	  pShell->add(pRadAR);
+	  pHoleForMixedStraw                    = makeStraw(false, GM_ARGON);
+	  pHoleForMixedStrawWithLargeDeadRegion = makeStraw(true, GM_ARGON);
 	  break;
 	case GM_KRYPTON:
 	  ATH_MSG_DEBUG( "Marking Krypton straws from /TRT/Cond/StatusHT:\t"
 			 << idHelper->print_to_string(TRT_Identifier));
-	  pShell->add(pRadKR);
+	  pHoleForMixedStraw                    = makeStraw(false, GM_KRYPTON);
+	  pHoleForMixedStrawWithLargeDeadRegion = makeStraw(true, GM_KRYPTON);
 	  break;
 	case GM_XENON:
 	  ATH_MSG_DEBUG( "Marking Xenon straws from /TRT/Cond/StatusHT:\t"
 			 << idHelper->print_to_string(TRT_Identifier) );
-	  pShell->add(pRad);
+	  pHoleForMixedStraw = makeStraw();
+	  pHoleForMixedStrawWithLargeDeadRegion = makeStraw(true);
 	  break;
 	default:
 	  ATH_MSG_FATAL( "Unexpected gas mixture: " << agm );
@@ -986,6 +921,20 @@ void TRTDetectorFactory_Full::create(GeoPhysVol *world)
 	  return;
 	}
 
+	GeoNodePtr<GeoSerialTransformer> serialTransformer = new GeoSerialTransformer(pHoleForMixedStraw
+										      , &tx2
+										      , m_data->barrelNumberOfStrawsInModule[iABC]-nStrawsWithLargeDeadRegion);
+
+	if (iABC==0) {
+	  GeoNodePtr<GeoSerialTransformer> serialTransformerDead = new GeoSerialTransformer(pHoleForMixedStrawWithLargeDeadRegion
+											    , &tx2Dead
+											    , nStrawsWithLargeDeadRegion);
+	  pRad->add(serialTransformerDead);
+	}
+	pRad->add(serialTransformer);
+
+	pShell->add(pRad);
+
 	//-------------------------------------------------------------------//
 	//                                                                   //
 	// Barrel readout:                                                   //
@@ -2119,16 +2068,13 @@ const GeoShape * TRTDetectorFactory_Full::makeModule ( double length, const GeoT
 //////////////////////////////////// makeStraw ///////////////////////////////////
 
 //
-//GeoPhysVol * TRTDetectorFactory_Full::makeStraw( double& activeGasZPosition, bool hasLargeDeadRegion /*= false*/ ) const {
-GeoPhysVol * TRTDetectorFactory_Full::makeStraw( double& activeGasZPosition, bool hasLargeDeadRegion /*= false*/, ActiveGasMixture gasMixture) {
+GeoPhysVol * TRTDetectorFactory_Full::makeStraw(bool hasLargeDeadRegion, ActiveGasMixture gasMixture) {
 
   double lengthOfInnerDeadRegion= hasLargeDeadRegion ? m_data->barrelLengthOfLargeDeadRegion : m_data->lengthOfDeadRegion ;
   double lengthOfActiveGas = (m_data->barrelLengthOfStraw-m_data->barrelLengthOfTwister)/2.0 - m_data->lengthOfDeadRegion - lengthOfInnerDeadRegion;
   double posA   = (lengthOfActiveGas + m_data->barrelLengthOfTwister) / 2. + lengthOfInnerDeadRegion; // middle of lengthOfActiveGas
   double posInnerDeadRegion = ( m_data->barrelLengthOfTwister + lengthOfInnerDeadRegion ) / 2;
 
-  activeGasZPosition=posA;
-
   // Straws:
   GeoTube    *sHole      = new GeoTube(0,m_data->barrelOuterRadiusOfStrawHole, m_data->barrelLengthOfStraw/2.0);
   GeoLogVol  *lHole      = new GeoLogVol("Hole", sHole, m_materialManager->getMaterial("trt::CO2"));