ITS3: Digitizer option to pick response function

Signed-off-by: Felix Schlepper <felix.schlepper@cern.ch>

Author: f3sch

Detectors/Upgrades/ITS3/base/include/ITS3Base/ITS3Params.h

@@ -25,7 +25,10 @@ struct ITS3Params : public o2::conf::ConfigurableParamHelper<ITS3Params> {
   bool misalignmentHitsUseProp{false};                                              // Use propagtor for mis-alignment
   std::string globalGeoMisAlignerMacro{"${O2_ROOT}/share/macro/MisAlignGeoITS3.C"}; // Path to macro for global geometry mis-alignment
   // Chip studies
-  bool useDeadChannelMap{false}; // Query for a dead channel map to study disabling individual tiles
+  bool useDeadChannelMap{false};               // Query for a dead channel map to study disabling individual tiles
+  std::string chipResponseFunction{"APTS"};    // Chip response function one of "Alpide", "APTS" or "Mosaix" (not yet available)
+  std::string responseFunctionIB{"response0"}; // Chip response function name for IB
+  std::string responseFunctionOB{"response1"}; // Chip response function name for 0B
 
   O2ParamDef(ITS3Params, "ITS3Params");
 };

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

@@ -18,15 +18,15 @@
 #include <deque>
 #include <memory>
 
-#include "Rtypes.h"  // for Digitizer::Class
-#include "TObject.h" // for TObject
+#include "Rtypes.h"
+#include "TObject.h"
 
 #include "ITSMFTSimulation/ChipDigitsContainer.h"
 #include "ITSMFTSimulation/AlpideSimResponse.h"
-#include "ITSMFTSimulation/DigiParams.h"
 #include "ITSMFTSimulation/Hit.h"
 #include "ITSBase/GeometryTGeo.h"
 #include "ITS3Base/SegmentationSuperAlpide.h"
+#include "ITS3Simulation/DigiParams.h"
 #include "DataFormatsITSMFT/Digit.h"
 #include "DataFormatsITSMFT/ROFRecord.h"
 #include "CommonDataFormat/InteractionRecord.h"
@@ -35,6 +35,7 @@
 
 namespace o2::its3
 {
+
 class Digitizer : public TObject
 {
   using ExtraDig = std::vector<itsmft::PreDigitLabelRef>; ///< container for extra contributions to PreDigits
@@ -44,8 +45,8 @@ class Digitizer : public TObject
   void setMCLabels(o2::dataformats::MCTruthContainer<o2::MCCompLabel>* mclb) { mMCLabels = mclb; }
   void setROFRecords(std::vector<o2::itsmft::ROFRecord>* rec) { mROFRecords = rec; }
 
-  o2::itsmft::DigiParams& getParams() { return (o2::itsmft::DigiParams&)mParams; }
-  const o2::itsmft::DigiParams& getParams() const { return mParams; }
+  o2::its3::DigiParams& getParams() { return mParams; }
+  const o2::its3::DigiParams& getParams() const { return mParams; }
 
   void init();
 
@@ -62,9 +63,6 @@ class Digitizer : public TObject
   bool isContinuous() const { return mParams.isContinuous(); }
   void fillOutputContainer(uint32_t maxFrame = 0xffffffff);
 
-  void setDigiParams(const o2::itsmft::DigiParams& par) { mParams = par; }
-  const o2::itsmft::DigiParams& getDigitParams() const { return mParams; }
-
   // provide the common itsmft::GeometryTGeo to access matrices and segmentation
   void setGeometry(const o2::its::GeometryTGeo* gm) { mGeometry = gm; }
 
@@ -97,7 +95,7 @@ class Digitizer : public TObject
 
   static constexpr float sec2ns = 1e9;
 
-  o2::itsmft::DigiParams mParams;          ///< digitization parameters
+  o2::its3::DigiParams mParams;            ///< digitization parameters
   o2::InteractionTimeRecord mEventTime;    ///< global event time and interaction record
   o2::InteractionRecord mIRFirstSampledTF; ///< IR of the 1st sampled IR, noise-only ROFs will be inserted till this IR only
   double mCollisionTimeWrtROF{};
@@ -110,7 +108,10 @@ class Digitizer : public TObject
 
   const std::array<o2::its3::SegmentationSuperAlpide, 3> mSuperSegmentations{0, 1, 2};
 
-  o2::itsmft::AlpideSimResponse* mAlpSimResp = nullptr; // simulated response
+  o2::itsmft::AlpideSimResponse* mSimRespIB = nullptr; // simulated response for IB
+  o2::itsmft::AlpideSimResponse* mSimRespOB = nullptr; // simulated response for OB
+  float mSimRespIBShift{0.};                           // adjusting the Y-shift in the IB response function to match sensor local coord.
+  float mSimRespOBShift{0.};                           // adjusting the Y-shift in the OB response function to match sensor local coord.
 
   const o2::its::GeometryTGeo* mGeometry = nullptr; ///< ITS3 geometry
 
@@ -123,8 +124,9 @@ class Digitizer : public TObject
 
   const o2::itsmft::NoiseMap* mDeadChanMap = nullptr;
 
-  ClassDef(Digitizer, 4);
+  ClassDef(Digitizer, 5);
 };
+
 } // namespace o2::its3
 
 #endif /* ALICEO2_ITS3_DIGITIZER_H */

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

@@ -14,6 +14,7 @@
 
 #include "ITSMFTBase/SegmentationAlpide.h"
 #include "ITS3Simulation/Digitizer.h"
+#include "ITS3Base/ITS3Params.h"
 #include "MathUtils/Cartesian.h"
 #include "SimulationDataFormat/MCTruthContainer.h"
 #include "DetectorsRaw/HBFUtils.h"
@@ -43,12 +44,39 @@ void Digitizer::init()
     }
   }
 
-  if (mParams.getAlpSimResponse() == nullptr) {
-    std::string responseFile = "$(O2_ROOT)/share/Detectors/ITSMFT/data/AlpideResponseData/AlpideResponseData.root";
-    LOGP(info, "Loading AlpideSimRespnse from file: {}", responseFile);
-    auto file = TFile::Open(responseFile.data());
-    mAlpSimResp = (o2::itsmft::AlpideSimResponse*)file->Get("response0"); // We use by default the alpide response for Vbb=0V
-    mParams.setAlpSimResponse(mAlpSimResp);
+  if (!mParams.hasResponseFunctions()) {
+    auto loadSetResponseFunc = [&](const char* fileIB, const char* fileOB, const char* name) {
+      const auto& nameIB = ITS3Params::Instance().responseFunctionIB;
+      const auto& nameOB = ITS3Params::Instance().responseFunctionOB;
+      LOGP(info, "Loading response function for {}: IB={}:{} / OB={}:{}", name, nameIB, fileIB, nameOB, fileOB);
+      auto fIB = TFile::Open(fileIB);
+      if (fIB->IsZombie() || !fIB->IsOpen()) {
+        LOGP(fatal, "Cannot open file {}", fileIB);
+      }
+      auto fOB = TFile::Open(fileIB);
+      if (fOB->IsZombie() || !fOB->IsOpen()) {
+        LOGP(fatal, "Cannot open file {}", fileOB);
+      }
+      mParams.setIBSimResponse(mSimRespIB = fIB->Get<o2::itsmft::AlpideSimResponse>(nameIB.c_str()));
+      mParams.setOBSimResponse(mSimRespOB = fOB->Get<o2::itsmft::AlpideSimResponse>(nameOB.c_str()));
+      fIB->Close();
+      fOB->Close();
+    };
+
+    if (const auto& func = ITS3Params::Instance().chipResponseFunction; func == "Alpide") {
+      constexpr const char* responseFile = "$(O2_ROOT)/share/Detectors/ITSMFT/data/AlpideResponseData/AlpideResponseData.root";
+      loadSetResponseFunc(responseFile, responseFile, "Alpide");
+      mSimRespIBShift = mSimRespIB->getDepthMax() - SegmentationSuperAlpide::mSensorLayerThickness / 2.f;
+      mSimRespOBShift = mSimRespOB->getDepthMax() - Segmentation::SensorLayerThickness / 2.f;
+    } else if (func == "APTS") {
+      constexpr const char* responseFileIB = "$(O2_ROOT)/share/Detectors/Upgrades/ITS3/data/ITS3ChipResponseData/APTSResponseData.root";
+      constexpr const char* responseFileOB = "$(O2_ROOT)/share/Detectors/ITSMFT/data/AlpideResponseData/AlpideResponseData.root";
+      loadSetResponseFunc(responseFileIB, responseFileOB, "APTS");
+      mSimRespIBShift = mSimRespIB->getDepthMax() - 10.e-4f;
+      mSimRespOBShift = mSimRespOB->getDepthMax() - Segmentation::SensorLayerThickness / 2.f;
+    } else {
+      LOGP(fatal, "ResponseFunction '{}' not implemented!", func);
+    }
   }
   mParams.print();
   mIRFirstSampledTF = o2::raw::HBFUtils::Instance().getFirstSampledTFIR();
@@ -326,8 +354,8 @@ void Digitizer::processHit(const o2::itsmft::Hit& hit, uint32_t& maxFr, int evID
   // take into account that the AlpideSimResponse depth defintion has different min/max boundaries
   // although the max should coincide with the surface of the epitaxial layer, which in the chip
   // local coordinates has Y = +SensorLayerThickness/2
-  float thickness = innerBarrel ? SegmentationSuperAlpide::mSensorLayerThickness : Segmentation::SensorLayerThickness;
-  xyzLocS.SetY(xyzLocS.Y() + mAlpSimResp->getDepthMax() - thickness / 2.);
+  xyzLocS.SetY(xyzLocS.Y() + ((innerBarrel) ? mSimRespIBShift : mSimRespOBShift));
+
   // collect charge in evey pixel which might be affected by the hit
   for (int iStep = nSteps; iStep--;) {
     // Get the pixel ID
@@ -349,9 +377,9 @@ void Digitizer::processHit(const o2::itsmft::Hit& hit, uint32_t& maxFr, int evID
     }
     bool flipCol = false, flipRow = false;
     // note that response needs coordinates along column row (locX) (locZ) then depth (locY)
-    double rowMax{0.5f * (innerBarrel ? SegmentationSuperAlpide::mPitchRow : Segmentation::PitchRow)};
-    double colMax{0.5f * (innerBarrel ? SegmentationSuperAlpide::mPitchCol : Segmentation::PitchCol)};
-    auto rspmat = mAlpSimResp->getResponse(xyzLocS.X() - cRowPix, xyzLocS.Z() - cColPix, xyzLocS.Y(), flipRow, flipCol, rowMax, colMax);
+    float rowMax{0.5f * (innerBarrel ? SegmentationSuperAlpide::mPitchRow : Segmentation::PitchRow)};
+    float colMax{0.5f * (innerBarrel ? SegmentationSuperAlpide::mPitchCol : Segmentation::PitchCol)};
+    auto rspmat = ((innerBarrel) ? mSimRespIB : mSimRespOB)->getResponse(xyzLocS.X() - cRowPix, xyzLocS.Z() - cColPix, xyzLocS.Y(), flipRow, flipCol, rowMax, colMax);
 
     xyzLocS += step;
     if (rspmat == nullptr) {