Introduce CbmBeamGenerator

The new class CbmBeamGenerator is intended for transport simulation of the (non-interacting) beam through the CBM setup, to study beam-related background.

Some changes had to be applied to CbmEventGenerator. An example macro run_transport_beam.C was added as well.

macro/run/run_transport_beam.C

+/** @file run_transport_beam.C
+ ** @author Volker Friese <v.friese@gsi.de>
+ ** @since 9 September 2020
+ **/
+
+// Includes needed for IDE
+#if !defined(__CLING__)
+#include "CbmBeamGenerator";
+#include "CbmTransport.h"
+#include "FairSystemInfo.h"
+#include "TStopwatch.h"
+#endif
+
+
+/** @brief run_transport_beam
+ ** @author Volker Friese <v.friese@gsi.de>
+ ** @since  9 September 2020
+ ** @param nEvents    Number of events from input to transport
+ ** @param setupName  Name of predefined geometry setup
+ ** @param output     Name of output data set
+ ** @param inputFile  Name of input file
+ **
+ ** Macro for transport simulation of beam particles in the CBM setup.
+ ** Properties of the beam have to be specified in the macro body.
+ **
+ ** For the setup (geometry and field), predefined setups can be chosen
+ ** by the second argument. Available setups are in geometry/setup.
+ **
+ ** The output file will be named [output].tra.root.
+ ** A parameter file [output].par.root will be created.
+ ** The geometry (TGeoManager) will be written into [output].geo.root.
+ **
+ ** For the options for the transport simulation, see the documentation of
+ ** CbmTransport.
+ **/
+void run_transport_beam(Int_t nEvents         = 1000,
+                        const char* setupName = "sis100_electron",
+                        const char* output    = "beam") {
+
+  // --- Logger settings ----------------------------------------------------
+  FairLogger::GetLogger()->SetLogScreenLevel("INFO");
+  FairLogger::GetLogger()->SetLogVerbosityLevel("LOW");
+  // ------------------------------------------------------------------------
+
+
+  // -----   Environment   --------------------------------------------------
+  TString myName = "run_transport_beam";  // this macro's name for screen output
+  TString srcDir = gSystem->Getenv("VMCWORKDIR");  // top source directory
+  // ------------------------------------------------------------------------
+
+
+  // -----   File names   ---------------------------------------------------
+  TString dataset(output);
+  TString outFile = dataset + ".tra.root";
+  TString parFile = dataset + ".par.root";
+  TString geoFile = dataset + ".geo.root";
+  // ------------------------------------------------------------------------
+
+
+  // ----   Define the beam   -----------------------------------------------
+  // Beam species here is full stripped Gold
+  UInt_t beamZ        = 79;   // atomic number
+  UInt_t beamA        = 197;  // mass number
+  UInt_t beamQ        = 79;   // charge (fully stripped)
+  Double_t beamP      = 12.;  // Momentum 12 GeV per nucleon
+  Double_t beamStartZ = -1.;  // Starts at z = -1 cm
+  // ------------------------------------------------------------------------
+
+
+  // ----   Define the beam profile   ---------------------------------------
+  Double_t beamFocusZ  = 0.;   // z coordinate of beam focal plane
+  Double_t beamMeanX   = 0.;   // mean x position of beam [cm]
+  Double_t beamSigmaX  = 0.1;  // Gaussian sigma of beam x position [cm]
+  Double_t beamMeanY   = 0.;   // mean y position of beam [cm]
+  Double_t beamSigmaY  = 0.1;  // Gaussian sigma of beam y position [cm]
+  Double_t beamMeanTx  = 0.;   // mean x-z angle of beam [rad]
+  Double_t beamSigmaTx = 1.;   // Gaussian sigma of beam x-z angle [rad]
+  Double_t beamMeanTy  = 0.;   // mean x-y angle of beam [rad]
+  Double_t beamSigmaTy = 1.;   // Gaussian sigma of beam x-y angle [rad]
+  // ------------------------------------------------------------------------
+
+
+  // -----   Timer   --------------------------------------------------------
+  TStopwatch timer;
+  timer.Start();
+  // ------------------------------------------------------------------------
+
+
+  // --- Transport run   ----------------------------------------------------
+  CbmTransport run;
+  run.SetOutFileName(outFile);
+  run.SetParFileName(parFile);
+  run.SetGeoFileName(geoFile);
+  run.LoadSetup(setupName);
+  run.SetTarget("Gold", 0.025, 2.5);
+  run.SetBeamPosition(beamMeanX, beamMeanY, beamSigmaX, beamSigmaY, beamFocusZ);
+  run.SetBeamAngle(beamMeanTx, beamMeanTy, beamSigmaTx, beamSigmaTy);
+  run.AddInput(new CbmBeamGenerator(beamZ, beamA, beamQ, beamP, beamStartZ));
+  run.Run(nEvents);
+  // ------------------------------------------------------------------------
+
+
+  // -----   Finish   -------------------------------------------------------
+  timer.Stop();
+  Double_t rtime = timer.RealTime();
+  Double_t ctime = timer.CpuTime();
+  std::cout << std::endl << std::endl;
+  std::cout << "Macro finished successfully." << std::endl;
+  std::cout << "Output file is " << outFile << std::endl;
+  std::cout << "Parameter file is " << parFile << std::endl;
+  std::cout << "Real time " << rtime << " s, CPU time " << ctime << "s"
+            << std::endl
+            << std::endl;
+  // ------------------------------------------------------------------------
+
+
+  // -----   Resource monitoring   ------------------------------------------
+  FairSystemInfo sysInfo;
+  Float_t maxMemory = sysInfo.GetMaxMemory();
+  std::cout << "<DartMeasurement name=\"MaxMemory\" type=\"numeric/double\">";
+  std::cout << maxMemory;
+  std::cout << "</DartMeasurement>" << std::endl;
+
+  Float_t cpuUsage = ctime / rtime;
+  std::cout << "<DartMeasurement name=\"CpuLoad\" type=\"numeric/double\">";
+  std::cout << cpuUsage;
+  std::cout << "</DartMeasurement>" << std::endl;
+
+
+  std::cout << " Test passed" << std::endl;
+  std::cout << " All ok " << std::endl;
+  // ------------------------------------------------------------------------
+
+}  // End of macro