testTPCElectronTransport.cxx

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// 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.
 
 
#define BOOST_TEST_MODULE Test TPC ElectronTransport
#define BOOST_TEST_MAIN
#define BOOST_TEST_DYN_LINK
#include <boost/test/unit_test.hpp>
#include "TPCSimulation/ElectronTransport.h"
#include "TPCBase/ParameterGas.h"
#include "TPCBase/ParameterDetector.h"
#include "TPCBase/CDBInterface.h"
 
#include "TH1D.h"
#include "TF1.h"
 
namespace o2
{
namespace tpc
{
 
BOOST_AUTO_TEST_CASE(ElectronDiffusion_test1)
{
  auto& gasParam = ParameterGas::Instance();
  auto& detParam = ParameterDetector::Instance();
  const GlobalPosition3D posEle(10.f, 10.f, 10.f);
  TH1D hTestDiffX("hTestDiffX", "", 500, posEle.X() - 10., posEle.X() + 10.);
  TH1D hTestDiffY("hTestDiffY", "", 500, posEle.Y() - 10., posEle.Y() + 10.);
  TH1D hTestDiffZ("hTestDiffZ", "", 500, posEle.Z() - 10., posEle.Z() + 10.);
 
  TF1 gausX("gausX", "gaus");
  TF1 gausY("gausY", "gaus");
  TF1 gausZ("gausZ", "gaus");
 
  static ElectronTransport& electronTransport = ElectronTransport::instance();
  float driftTime = 0.f;
 
  for (int i = 0; i < 500000; ++i) {
    const GlobalPosition3D posEleDiff = electronTransport.getElectronDrift(posEle, driftTime);
    hTestDiffX.Fill(posEleDiff.X());
    hTestDiffY.Fill(posEleDiff.Y());
    hTestDiffZ.Fill(posEleDiff.Z());
  }
 
  hTestDiffX.Fit("gausX", "Q0");
  hTestDiffY.Fit("gausY", "Q0");
  hTestDiffZ.Fit("gausZ", "Q0");
 
  // check whether the mean of the gaussian fit matches the starting point
  BOOST_CHECK_CLOSE(gausX.GetParameter(1), posEle.X(), 0.5);
  BOOST_CHECK_CLOSE(gausY.GetParameter(1), posEle.Y(), 0.5);
  BOOST_CHECK_CLOSE(gausZ.GetParameter(1), posEle.Z(), 0.5);
 
  // check whether the width of the distribution matches the expected one
  const float sigT = std::sqrt(detParam.TPClength - posEle.Z()) * gasParam.DiffT;
  const float sigL = std::sqrt(detParam.TPClength - posEle.Z()) * gasParam.DiffL;
 
  BOOST_CHECK_CLOSE(gausX.GetParameter(2), sigT, 0.5);
  BOOST_CHECK_CLOSE(gausY.GetParameter(2), sigT, 0.5);
  BOOST_CHECK_CLOSE(gausZ.GetParameter(2), sigL, 0.5);
}
 
BOOST_AUTO_TEST_CASE(ElectronDiffusion_test2)
{
  auto& gasParam = ParameterGas::Instance();
  auto& detParam = ParameterDetector::Instance();
  const GlobalPosition3D posEle(1.f, 1.f, detParam.TPClength - 1.f);
  TH1D hTestDiffX("hTestDiffX", "", 500, posEle.X() - 1., posEle.X() + 1.);
  TH1D hTestDiffY("hTestDiffY", "", 500, posEle.Y() - 1., posEle.Y() + 1.);
  TH1D hTestDiffZ("hTestDiffZ", "", 500, posEle.Z() - 1., posEle.Z() + 1.);
 
  TF1 gausX("gausX", "gaus");
  TF1 gausY("gausY", "gaus");
  TF1 gausZ("gausZ", "gaus");
 
  static ElectronTransport& electronTransport = ElectronTransport::instance();
  float driftTime = 0.f;
 
  for (int i = 0; i < 500000; ++i) {
    const GlobalPosition3D posEleDiff = electronTransport.getElectronDrift(posEle, driftTime);
    hTestDiffX.Fill(posEleDiff.X());
    hTestDiffY.Fill(posEleDiff.Y());
    hTestDiffZ.Fill(posEleDiff.Z());
  }
 
  hTestDiffX.Fit("gausX", "Q0");
  hTestDiffY.Fit("gausY", "Q0");
  hTestDiffZ.Fit("gausZ", "Q0");
 
  // check whether the mean of the gaussian fit matches the starting point
  BOOST_CHECK_CLOSE(gausX.GetParameter(1), posEle.X(), 0.5);
  BOOST_CHECK_CLOSE(gausY.GetParameter(1), posEle.Y(), 0.5);
  BOOST_CHECK_CLOSE(gausZ.GetParameter(1), posEle.Z(), 0.5);
 
  // check whether the width of the distribution matches the expected one
  BOOST_CHECK_CLOSE(gausX.GetParameter(2), gasParam.DiffT, 0.5);
  BOOST_CHECK_CLOSE(gausY.GetParameter(2), gasParam.DiffT, 0.5);
  BOOST_CHECK_CLOSE(gausZ.GetParameter(2), gasParam.DiffL, 0.5);
}
 
BOOST_AUTO_TEST_CASE(ElectronAttatchment_test_1)
{
  auto& gasParam = ParameterGas::Instance();
  static ElectronTransport& electronTransport = ElectronTransport::instance();
 
  const float driftTime = 100.f;
  float lostElectrons = 0;
  const float nEvents = 1000000;
  for (int i = 0; i < nEvents; ++i) {
    if (electronTransport.isElectronAttachment(driftTime)) {
      ++lostElectrons;
    }
  }
 
  BOOST_CHECK_CLOSE(lostElectrons / nEvents,
                    gasParam.AttCoeff * gasParam.OxygenCont * driftTime, 0.5);
}
} // namespace tpc
} // namespace o2