- //------------------------------------------------
- // The magnetic field map, defined externally...
- // L3 current 30000 A -> 0.5 T
- // L3 current 12000 A -> 0.2 T
- // dipole current 6000 A
- // The polarities must be the same
- //------------------------------------------------
- const Float_t l3NominalCurrent1=30000.; // (A)
- const Float_t l3NominalCurrent2=12000.; // (A)
- const Float_t diNominalCurrent =6000. ; // (A)
-
- const Float_t tolerance=0.03; // relative current tolerance
- const Float_t zero=77.; // "zero" current (A)
- //
- TString s=(l3Pol < 0) ? "L3: -" : "L3: +";
- //
- AliMagF::BMap_t map = AliMagF::k5kG;
- //
- double fcL3,fcDip;
- //
- l3Cur = TMath::Abs(l3Cur);
- if (TMath::Abs(l3Cur-l3NominalCurrent1)/l3NominalCurrent1 < tolerance) {
- fcL3 = l3Cur/l3NominalCurrent1;
- map = AliMagF::k5kG;
- s += "0.5 T; ";
- } else if (TMath::Abs(l3Cur-l3NominalCurrent2)/l3NominalCurrent2 < tolerance) {
- fcL3 = l3Cur/l3NominalCurrent2;
- map = AliMagF::k2kG;
- s += "0.2 T; ";
- } else if (l3Cur <= zero) {
- fcL3 = 0;
- map = AliMagF::k5kGUniform;
- s += "0.0 T; ";
- // fUniformField=kTRUE; // track with the uniform (zero) B field
- } else {
- AliError(Form("Wrong L3 current (%f A)!",l3Cur));
- return kFALSE;
- }
- //
- diCur = TMath::Abs(diCur);
- if (TMath::Abs(diCur-diNominalCurrent)/diNominalCurrent < tolerance) {
- // 3% current tolerance...
- fcDip = diCur/diNominalCurrent;
- s += "Dipole ON";
- } else if (diCur <= zero) { // some small current..
- fcDip = 0.;
- s += "Dipole OFF";
- } else {
- AliError(Form("Wrong dipole current (%f A)!",diCur));
- return kFALSE;
- }
- //
- if (l3Pol!=diPol && (map==AliMagF::k5kG || map==AliMagF::k2kG) && fcDip!=0) {
- AliError("L3 and Dipole polarities must be the same");
- return kFALSE;
- }
- //
- if (l3Pol<0) fcL3 = -fcL3;
- if (diPol<0) fcDip = -fcDip;
- //
- AliMagF::BeamType_t btype = AliMagF::kNoBeamField;
- TString btypestr = beamtype;
- btypestr.ToLower();
- TPRegexp protonBeam("(proton|p)\\s*-?\\s*\\1");
- TPRegexp ionBeam("(lead|pb|ion|a)\\s*-?\\s*\\1");
- if (btypestr.Contains(ionBeam)) btype = AliMagF::kBeamTypeAA;
- else if (btypestr.Contains(protonBeam)) btype = AliMagF::kBeamTypepp;
- else {
- AliInfo(Form("Cannot determine the beam type from %s, assume no LHC magnet field",beamtype));
- }
-
- AliMagF* fld = new AliMagF("MagneticFieldMap", s.Data(), 2, fcL3, fcDip, 10., map, path,
- btype,beamenergy);
- TGeoGlobalMagField::Instance()->SetField( fld );
- TGeoGlobalMagField::Instance()->Lock();