BOSS_7.0.2: /home/bes3soft/bes3soft/Boss/7.0.2/dist/7.0.2/Analysis/VertexFit/VertexFit-00-02-78/src/BField.cxx Source File

00001 #include <cassert>
00002 
00003 #ifndef BEAN
00004 #include "GaudiKernel/MsgStream.h"
00005 #include "GaudiKernel/ISvcLocator.h"
00006 #include "GaudiKernel/IDataProviderSvc.h"
00007 #include "GaudiKernel/Bootstrap.h"
00008 #endif
00009 
00010 #include "VertexFit/BField.h"
00011 #include "CLHEP/Geometry/Vector3D.h"
00012 #ifndef ENABLE_BACKWARDS_COMPATIBILITY
00013 typedef HepGeom::Vector3D<double> HepVector3D;
00014 #endif
00015 
00016 using namespace std;
00017 
00018 const double VertexFitBField::alpha = -0.00299792458;
00019 
00020 VertexFitBField* VertexFitBField::s_bfield = 0;
00021 
00022 VertexFitBField::VertexFitBField() {
00023 #ifndef BEAN
00024   ISvcLocator* svcLocator = Gaudi::svcLocator();
00025   m_pIMF = NULL;
00026   StatusCode sc = svcLocator->service("MagneticFieldSvc",m_pIMF);
00027   assert(m_pIMF != NULL);
00028   if (sc != StatusCode::SUCCESS) {
00029     std::cout << "ERROR : Unable to open Magnetic field service" << std::endl; 
00030 //    assert(false);
00031   }
00032 #else
00033   m_pIMF = MagneticFieldSvc::instance();
00034   assert( m_pIMF != 0 );
00035   if( (m_pIMF->GetPath()).empty() ) {
00036     cout << " VertexFitBField::ERROR "
00037         "You MUST set path to directory with magnetic fields tables" << endl;
00038     exit(1);
00039   }
00040   if( !m_pIMF->initialize() ) {
00041     cout << "ERROR : Can not initialize MagneticField. Stop." << endl;
00042     exit(1);
00043   }
00044 #endif
00045 }
00046 
00047 double VertexFitBField::getBFieldZ(const HepPoint3D& vtx) {
00048   HepVector3D vector(0.0, 0.0, 0.0);
00049   // fixed 2008-8-1
00050   double radius = sqrt(vtx.x()*vtx.x() + vtx.y()*vtx.y());
00051   if (radius < 150 && abs(vtx.z()) < 150) {
00052     m_pIMF->fieldVector(10.0*vtx, vector);
00053     return 1000 * vector.z();   //unit of m_BFieldZ is Tesla
00054   } else {
00055     return 1000 * m_pIMF->getReferField(); 
00056   }  
00057 }
00058 
00059 double VertexFitBField::getBFieldZRef() {
00060   return 1000 * m_pIMF->getReferField();
00061 }
00062 
00063 double VertexFitBField::getCBz(const HepVector& vtx, const HepVector& trackPosition) {
00064   HepPoint3D Vtx(vtx[0], vtx[1], vtx[2]);
00065   HepPoint3D TrkPosition(trackPosition[0], trackPosition[1], trackPosition[2]);
00066 
00067   HepVector3D vector_vtx(0.0, 0.0, 0.0);
00068   HepVector3D vector_trk(0.0, 0.0, 0.0);
00069   double radius = sqrt(vtx[0]*vtx[0] + vtx[1]*vtx[1]);
00070   if (radius < 150 && abs(vtx[2]) < 150) {
00071     m_pIMF->fieldVector(10.0*Vtx, vector_vtx);
00072     m_pIMF->fieldVector(10.0*TrkPosition, vector_trk);
00073     return 1000 * alpha * (vector_vtx.z() + vector_trk.z())/2;//unit of m_BFieldZ is Tesla
00074   } else {
00075     return 1000 * alpha* m_pIMF->getReferField();
00076   }
00077 }