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Question Problems of optical photon transmission 

Forum: Particles
Date: 23 May, 2013
From: yanxin0221 <yanxin0221>

Hi everyone, I'm new with geant4.I've got some problem with the optical photon transmission ! When I use 4eV photons at a certain angle from the water into the air,there is a big difference between the got angle of refraction and theoretical angle.Could you give me some idea or advices to solve this problem? Thanks a lot everybody. yours sincerely, Yanxin. The DetectorConstruction.cc is as follows #include "EADetectorConstruction.hh" #include "G4Material.hh" #include "G4Element.hh" #include "G4LogicalBorderSurface.hh" #include "G4LogicalSkinSurface.hh" #include "G4OpticalSurface.hh" #include "G4Box.hh" #include "G4LogicalVolume.hh" #include "G4ThreeVector.hh" #include "G4PVPlacement.hh" #include "G4SystemOfUnits.hh" #include "G4Tubs.hh" #include "G4Orb.hh" #include "G4PVReplica.hh" #include "G4SolidStore.hh" #include "G4NistManager.hh" #include "globals.hh" #include "G4VisAttributes.hh" #include "G4Colour.hh" //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... EADetectorConstruction::EADetectorConstruction() : expHall_log(0), waterTank_log(0), expHall_phys(0) ,waterTank_phys(0) { for(int j=0;j<88;j++) { tubedetectorl[j] =0; tubedetectorp[j] =0; } } //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... EADetectorConstruction::~EADetectorConstruction(){;} //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... G4VPhysicalVolume* EADetectorConstruction::Construct() { // ------------- Materials ------------- G4double a, z, density; G4int nelements; G4double expHall_x = 200.0*m; G4double expHall_y = 200.0*m; G4double expHall_z = 200.0*m; G4double tank_x = 5.0*m; G4double tank_y = 5.0*m; G4double tank_z = 5.0*m; // Air // G4Element* N = new G4Element("Nitrogen", "N", z=7 , a=14.01*g/mole); G4Element* O = new G4Element("Oxygen" , "O", z=8 , a=16.00*g/mole); G4Material* Air = new G4Material("Air", density=1.29*mg/cm3, nelements=2); Air->AddElement(N, 70.*perCent); Air->AddElement(O, 30.*perCent); // Water // G4Element* H = new G4Element("Hydrogen", "H", z=1 , a=1.01*g/mole); G4Material* Water = new G4Material("Water", density= 1.0*g/cm3, nelements=2); Water->AddElement(H, 2); Water->AddElement(O, 1); // // ------------ Generate & Add Material Properties Table ------------ // const G4int nEntries = 32; G4double PhotonEnergy[nEntries] = { 2.034*eV, 2.068*eV, 2.103*eV, 2.139*eV, 2.177*eV, 2.216*eV, 2.256*eV, 2.298*eV, 2.341*eV, 2.386*eV, 2.433*eV, 2.481*eV, 2.532*eV, 2.585*eV, 2.640*eV, 2.697*eV, 2.757*eV, 2.820*eV, 2.885*eV, 2.954*eV, 3.026*eV, 3.102*eV, 3.181*eV, 3.265*eV, 3.353*eV, 3.446*eV, 3.545*eV, 3.649*eV, 3.760*eV, 3.877*eV, 4.002*eV, 4.136*eV }; // // Water // G4double RefractiveIndex1[nEntries] = { 1.3435, 1.344, 1.3445, 1.345, 1.3455, 1.346, 1.3465, 1.347, 1.3475, 1.348, 1.3485, 1.3492, 1.35, 1.3505, 1.351, 1.3518, 1.3522, 1.3530, 1.3535, 1.354, 1.3545, 1.355, 1.3555, 1.356, 1.3568, 1.3572, 1.358, 1.3585, 1.359, 1.3595, 1.36, 1.3608}; G4double Absorption1[nEntries] = {3.448*m, 4.082*m, 6.329*m, 9.174*m, 12.346*m, 13.889*m, 15.152*m, 17.241*m, 18.868*m, 20.000*m, 26.316*m, 35.714*m, 45.455*m, 47.619*m, 52.632*m, 52.632*m, 55.556*m, 52.632*m, 52.632*m, 47.619*m, 45.455*m, 41.667*m, 37.037*m, 33.333*m, 30.000*m, 28.500*m, 27.000*m, 24.500*m, 22.000*m, 19.500*m, 17.500*m, 14.500*m }; G4double ScintilFast[nEntries] = { 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00 }; G4double ScintilSlow[nEntries] = { 0.01, 1.00, 2.00, 3.00, 4.00, 5.00, 6.00, 7.00, 8.00, 9.00, 8.00, 7.00, 6.00, 4.00, 3.00, 2.00, 1.00, 0.01, 1.00, 2.00, 3.00, 4.00, 5.00, 6.00, 7.00, 8.00, 9.00, 8.00, 7.00, 6.00, 5.00, 4.00 }; G4MaterialPropertiesTable* myMPT1 = new G4MaterialPropertiesTable(); myMPT1->AddProperty("RINDEX", PhotonEnergy, RefractiveIndex1,nEntries) ->SetSpline(true); myMPT1->AddProperty("ABSLENGTH", PhotonEnergy, Absorption1, nEntries) ->SetSpline(true); myMPT1->AddProperty("FASTCOMPONENT",PhotonEnergy, ScintilFast, nEntries) ->SetSpline(true); myMPT1->AddProperty("SLOWCOMPONENT",PhotonEnergy, ScintilSlow, nEntries) ->SetSpline(true); myMPT1->AddConstProperty("SCINTILLATIONYIELD",50./MeV); myMPT1->AddConstProperty("RESOLUTIONSCALE",1.0); myMPT1->AddConstProperty("FASTTIMECONSTANT", 1.*ns); myMPT1->AddConstProperty("SLOWTIMECONSTANT",10.*ns); myMPT1->AddConstProperty("YIELDRATIO",0.8); const G4int NUMENTRIES_water = 60; G4double ENERGY_water[NUMENTRIES_water] = { 1.56962*eV, 1.58974*eV, 1.61039*eV, 1.63157*eV, 1.65333*eV, 1.67567*eV, 1.69863*eV, 1.72222*eV, 1.74647*eV, 1.77142*eV, 1.7971 *eV, 1.82352*eV, 1.85074*eV, 1.87878*eV, 1.90769*eV, 1.93749*eV, 1.96825*eV, 1.99999*eV, 2.03278*eV, 2.06666*eV, 2.10169*eV, 2.13793*eV, 2.17543*eV, 2.21428*eV, 2.25454*eV, 2.29629*eV, 2.33962*eV, 2.38461*eV, 2.43137*eV, 2.47999*eV, 2.53061*eV, 2.58333*eV, 2.63829*eV, 2.69565*eV, 2.75555*eV, 2.81817*eV, 2.88371*eV, 2.95237*eV, 3.02438*eV, 3.09999*eV, 3.17948*eV, 3.26315*eV, 3.35134*eV, 3.44444*eV, 3.54285*eV, 3.64705*eV, 3.75757*eV, 3.87499*eV, 3.99999*eV, 4.13332*eV, 4.27585*eV, 4.42856*eV, 4.59258*eV, 4.76922*eV, 4.95999*eV, 5.16665*eV, 5.39129*eV, 5.63635*eV, 5.90475*eV, 6.19998*eV }; //assume 100 times larger than the rayleigh scattering for now. G4double MIE_water[NUMENTRIES_water] = { 167024.4*m, 158726.7*m, 150742 *m, 143062.5*m, 135680.2*m, 128587.4*m, 121776.3*m, 115239.5*m, 108969.5*m, 102958.8*m, 97200.35*m, 91686.86*m, 86411.33*m, 81366.79*m, 76546.42*m, 71943.46*m, 67551.29*m, 63363.36*m, 59373.25*m, 55574.61*m, 51961.24*m, 48527.00*m, 45265.87*m, 42171.94*m, 39239.39*m, 36462.50*m, 33835.68*m, 31353.41*m, 29010.30*m, 26801.03*m, 24720.42*m, 22763.36*m, 20924.88*m, 19200.07*m, 17584.16*m, 16072.45*m, 14660.38*m, 13343.46*m, 12117.33*m, 10977.70*m, 9920.416*m, 8941.407*m, 8036.711*m, 7202.470*m, 6434.927*m, 5730.429*m, 5085.425*m, 4496.467*m, 3960.210*m, 3473.413*m, 3032.937*m, 2635.746*m, 2278.907*m, 1959.588*m, 1675.064*m, 1422.710*m, 1200.004*m, 1004.528*m, 833.9666*m, 686.1063*m }; // gforward, gbackward, forward backward ratio G4double MIE_water_const[3]={0.99,0.99,0.8}; myMPT1->AddProperty("MIEHG",ENERGY_water,MIE_water,NUMENTRIES_water) ->SetSpline(true); myMPT1->AddConstProperty("MIEHG_FORWARD",MIE_water_const[0]); myMPT1->AddConstProperty("MIEHG_BACKWARD",MIE_water_const[1]); myMPT1->AddConstProperty("MIEHG_FORWARD_RATIO",MIE_water_const[2]); Water->SetMaterialPropertiesTable(myMPT1); // Set the Birks Constant for the Water scintillator Water->GetIonisation()->SetBirksConstant(0.126*mm/MeV); // // Air // G4double RefractiveIndex2[nEntries] = { 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00 }; G4MaterialPropertiesTable* myMPT2 = new G4MaterialPropertiesTable(); myMPT2->AddProperty("RINDEX", PhotonEnergy, RefractiveIndex2, nEntries); Air->SetMaterialPropertiesTable(myMPT2); // // ------------- Volumes -------------- // The experimental Hall // G4Box* expHall_box = new G4Box("World",expHall_x,expHall_y,expHall_z); expHall_log = new G4LogicalVolume(expHall_box,Air,"World",0,0,0); expHall_phys = new G4PVPlacement(0,G4ThreeVector(),expHall_log,"World",0,false,0); // The Water Tank // G4Box* waterTank_box = new G4Box("Tank",tank_x,tank_y,tank_z); waterTank_log = new G4LogicalVolume(waterTank_box,Water,"Tank",0,0,0); waterTank_phys = new G4PVPlacement(0,G4ThreeVector(),waterTank_log,"Tank", expHall_log,false,0); G4double x; G4double y; G4int i; for(int j=0;j<88;j++) { i=j+1; x=tan(j*3.1415926/180)*6; y=tan(i*3.1415926/180)*6; //G4cout << "x="<SetVisibility(true); //AuVisAtt->SetForceSolid(true); tubedetectorl[j] ->SetVisAttributes(tubedetectorlVisAtt); G4VisAttributes* expHall_logVisAtt= new G4VisAttributes(G4Colour(1.0,1.0,1.0)); expHall_log ->SetVisAttributes(expHall_logVisAtt); G4VisAttributes* waterTank_logVisAtt= new G4VisAttributes(G4Colour(1.0,0.0,1.0)); waterTank_log ->SetVisAttributes(waterTank_logVisAtt); //G4VisAttributes* bubbleAir_logVisAtt= new G4VisAttributes(G4Colour(1.0,1.0,0.0)); //bubbleAir_log ->SetVisAttributes(bubbleAir_logVisAtt); // ------------- Surfaces -------------- // // Water Tank G4OpticalSurface* OpWaterSurface = new G4OpticalSurface("WaterSurface"); OpWaterSurface->SetType(dielectric_dielectric); OpWaterSurface->SetFinish(ground); OpWaterSurface->SetModel(unified); new G4LogicalBorderSurface("WaterSurface", waterTank_phys,expHall_phys,OpWaterSurface); // Air Bubble G4OpticalSurface* OpAirSurface = new G4OpticalSurface("AirSurface"); OpAirSurface->SetType(dielectric_dielectric); OpAirSurface->SetFinish(polished); OpAirSurface->SetModel(glisur); G4LogicalSkinSurface* AirSurface = new G4LogicalSkinSurface("AirSurface", tubedetectorl[j], OpAirSurface); G4OpticalSurface* opticalSurface = dynamic_cast (AirSurface->GetSurface(tubedetectorl[j])->GetSurfaceProperty()); if (opticalSurface) opticalSurface->DumpInfo(); // // Generate & Add Material Properties Table attached to the optical surfaces // const G4int num = 2; G4double Ephoton[num] = {2.034*eV, 4.136*eV}; //OpticalWaterSurface G4double RefractiveIndex[num] = {1.35, 1.40}; G4double SpecularLobe[num] = {0.3, 0.3}; G4double SpecularSpike[num] = {0.2, 0.2}; G4double Backscatter[num] = {0.2, 0.2}; G4MaterialPropertiesTable* myST1 = new G4MaterialPropertiesTable(); myST1->AddProperty("RINDEX", Ephoton, RefractiveIndex, num); myST1->AddProperty("SPECULARLOBECONSTANT", Ephoton, SpecularLobe, num); myST1->AddProperty("SPECULARSPIKECONSTANT", Ephoton, SpecularSpike, num); myST1->AddProperty("BACKSCATTERCONSTANT", Ephoton, Backscatter, num); OpWaterSurface->SetMaterialPropertiesTable(myST1); //OpticalAirSurface G4double Reflectivity[num] = {0.3, 0.5}; G4double Efficiency[num] = {0.8, 1.0}; G4MaterialPropertiesTable *myST2 = new G4MaterialPropertiesTable(); myST2->AddProperty("REFLECTIVITY", Ephoton, Reflectivity, num); myST2->AddProperty("EFFICIENCY", Ephoton, Efficiency, num); OpAirSurface->SetMaterialPropertiesTable(myST2); }; //always return the physical World return expHall_phys; }

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