void runMCFOPI_const(Int_t field, 
		TString gas,
		Int_t gain,
		TString outdir,
		int nEvents=5000,
		Int_t run = 1,
		unsigned int seed=0,
		TString addon="",
		Int_t type=0, //0=along y; 1= along x; 2=any angle
		Double_t phi=0,
		Double_t theta=0,
		Int_t bfield=1
)
{

	// ------------------------------------------------------------------------
	gRandom->SetSeed(seed);

	// ========================================================================
	// Verbosity level (0=quiet, 1=event level, 2=track level, 3=debug)
	Int_t iVerbose = 1;
	FairRunSim *fRun = new FairRunSim();

	// set the MC version used
	// --------------------------------------------------
	TString mcMode = "TGeant3";
	fRun->SetName(mcMode);

	TString jobdir=outdir;
	int length = jobdir.Length();
	if(jobdir[length-1] != "/")
		jobdir.Append("/");

	TString jobname=Form("Cosmics_FopiMC_%i%s%i_%i.mc.root",field,gas.Data(),gain,run);
	TString outfile = jobdir+jobname;
	std::cout<<outfile<<std::endl;
	fRun->SetOutputFile(outfile);
	std::cout<<"Set output file to "<<outfile<<std::endl;

	TString copy = outfile;
	TString parfile = copy.ReplaceAll("mc.root","param.root");
	TString digifile = gSystem->Getenv("VMCWORKDIR");
	digifile += Form("/tpc/FOPI/par/tpc.%i%s%iMC",field,gas.Data(),gain);
	digifile += addon;
	digifile += ".par";
	std::cout<<digifile<<std::endl;

	FairRuntimeDb *rtdb=fRun->GetRuntimeDb();
	FairParAsciiFileIo* parIo1 = new FairParAsciiFileIo();
	parIo1->open(digifile.Data(),"in");
	rtdb->setFirstInput(parIo1);
	Bool_t kParameterMerged=kTRUE;

	FairParRootFileIo* parOut=new FairParRootFileIo(kParameterMerged);
	parOut->open(parfile.Data());
	rtdb->setOutput(parOut);

	// In general, the following parts need not be touched
	// ========================================================================
	// -----   Timer   --------------------------------------------------------
	TStopwatch timer;
	timer.Start();
	// ------------------------------------------------------------------------
	// Set Material file Name
	//-----------------------
	fRun->SetMaterials("media_pnd.geo");

	TpcDigiPar* par = (TpcDigiPar*) rtdb->getContainer("TpcDigiPar");
	par->setInputVersion(fRun->GetRunId(),1);
	par->setChanged(kTRUE);
	par->init();

	Double_t taroff = -65;
	Double_t targetpos = taroff+41.;
	// possible materials: copper (default), lead, carbon
	TString targetmat = TString("copper");
	TString alignmentFileName = par->getAlignmentFile();

	TFile* geotmp =new TFile("geometry/FOPI_TPC.root","READ");
	if(geotmp->IsOpen())
	{
		std::cout<<"geofile exists already\n";
		geotmp->Close();
	}
	else
	{
		TString  command;
		command.Form(".! root -b -q  '$PANDAPATH/macro/tpc/FOPI/make_TPC_geo.C(true,\"%s\")'",alignmentFileName.Data());
		std::cout<<command<<std::endl;
		gROOT->ProcessLine(command);
	}

	FairModule *Cave= new PndCave("CAVE");
	Cave->SetGeometryFileName("pndcave.geo");
	fRun->AddModule(Cave);

	TpcDetector *Tpc = new TpcDetector("TPC", kTRUE);
	Tpc->SetGeometryFileName("FOPI_TPC.root");
	Tpc->SetMixture("TPCFOPI_mix"); // TPCFOPI_mix: Ar CO2 (90/10)
	if(mcMode=="TGeant3") Tpc->SetAliMC();
	//Tpc->SetAllSensitive(kTRUE);
	fRun->AddModule(Tpc);

	FairPrimaryGenerator* primGen = new FairPrimaryGenerator();
	fRun->SetGenerator(primGen);

	FairBoxGeneratorMOD* boxGen = new FairBoxGeneratorMOD(-13,1);
	boxGen->SetPRange(2,10.); // GeV/c (2,10)
	boxGen->SetRandAntiPart();
	boxGen->SetDebug(0);

	//Standart Box generator setting
	//along y-axis
	if (type==0)
	{
		double shift=0.;
		shift=(16.+15.)/TMath::Tan(phi*TMath::DegToRad());
		//boxGen->SetPhiRange(270.,270.); // Azimuth angle range [degree]; along Y
		boxGen->SetPhiRange(180.,180.); // Azimuth angle range [degree]; along X
		//boxGen->SetThetaRange(phi,phi); // Polar angle in lab system range [degree]
		//boxGen->SetBoxXYZ(-16.,16. , 16.,16.,-1-shift,73);
		theta=phi;
		if (theta>2 && theta<178)
		{
			double shift=0.;
			if (theta!=-1)
			{
				boxGen->SetThetaRange(theta,theta);
				//boxGen->SetThetaRange(0,90);
				shift=(16.+15.)/TMath::Tan(theta*TMath::DegToRad());
			}
			else
			{
				boxGen->SetThetaRange(0,180);
			}
			//boxGen->SetBoxXYZ(-16.,16. , 16.,16.,-1-shift,73); //for along Y
			boxGen->SetBoxXYZ(16.,16. , -16.,16.,-1-shift,73); //for along X

		}
		else
		{
			if (theta<=2)
				boxGen->SetDonut(4.5,15.5,-1,-1);
			if (theta>=178)
				boxGen->SetDonut(4.5,15.5,74,74);

			boxGen->SetThetaRange(theta,theta);
		}
	}
	//along x-axis
	else if (type==1)
	{
		boxGen->SetPhiRange(180.,180.); // Azimuth angle range [degree]
		boxGen->SetThetaRange(90.,90.); // Polar angle in lab system range [degree]
		boxGen->SetBoxXYZ(16.,16. , -16.,16.,-1.,73.);
	}
	//along any angle
	else if (type==2)
	{
		boxGen->SetPhiRange(270-phi,270-phi); // Azimuth angle range [degree]
		double phi_rad=phi*TMath::DegToRad();
		double x1=TMath::Sin(phi_rad)*16-TMath::Cos(phi_rad)*16; //sin(phi)*height - cos(phi)*rad
		double y1=TMath::Cos(phi_rad)*16+TMath::Sin(phi_rad)*16;
		double x2=TMath::Sin(phi_rad)*16+TMath::Cos(phi_rad)*16;
		double y2=TMath::Cos(phi_rad)*16-TMath::Sin(phi_rad)*16;
		boxGen->SetThetaRange(90. , 90.); // Polar angle in lab system range [degree]
		boxGen->SetPlane1XYZ(x1,x2, y1,y2,-1,73.);
	}
	else
	{
		std::cout<<"no type given, quitting\n";
		return;
	}
	primGen->AddGenerator(boxGen);

	// Create and Set Magnetic Field
	// --------------------
	// Constant Field
	//PndConstField *fMagField=new PndConstField();
	//fMagField->SetField(0., 0. , 0. ); // values are in kG
	//fMagField->SetFieldRegion(-50, 50,-50, 50, -2000, 2000); // values are in cm
	Double_t taroff= -65;
	FOPIField * fMagField = new FOPIField(0.616);
	fMagField->SetTargetOffset(taroff);
	if (bfield==1)
		fRun->SetField(fMagField);

	/**Initialize the session*/
	fRun->Init();

	rtdb->saveOutput();
	rtdb->print();

	// Transport nEvents
	// -----------------
	fRun->Run(nEvents);


	timer.Stop();
	Double_t rtime = timer.RealTime();
	Double_t ctime = timer.CpuTime();
	std::cout << std::endl << std::endl;
	std::cout << "Macro finished succesfully." << 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::cout << std::endl;
	// ------------------------------------------------------------------------


}