Merge pull request #248 from kvjmistry/MetalReflections

Add reflections on copper and SS
next-exp · Mar 4, 2024 · 8ab477c · 8ab477c
2 parents e0352a4 + 78b66ea
commit 8ab477c
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diff --git a/source/geometries/Next100EnergyPlane.cc b/source/geometries/Next100EnergyPlane.cc
@@ -219,6 +219,16 @@ namespace nexus {
     copper_plate_posz_ = GetCoordOrigin().z()
       + gate_sapphire_wdw_dist_ + stand_out_length + copper_plate_thickn_/2.;
 
+    // Add optical surface
+    G4OpticalSurface* gas_copperplate_opsur = new G4OpticalSurface("GAS_COPPER_PLATE_OPSURF");
+    gas_copperplate_opsur->SetType(dielectric_metal);
+    gas_copperplate_opsur->SetModel(unified);
+    gas_copperplate_opsur->SetFinish(ground);
+    gas_copperplate_opsur->SetSigmaAlpha(0.0);
+    gas_copperplate_opsur->SetMaterialPropertiesTable(opticalprops::Copper());
+    new G4LogicalSkinSurface("GAS_COPPER_PLATE_OPSURF",
+                            copper_plate_logic, gas_copperplate_opsur);
+
     new G4PVPlacement(0, G4ThreeVector(0., 0., copper_plate_posz_),
                       copper_plate_logic, "EP_COPPER_PLATE", mother_logic_, false, 0, false);
 

diff --git a/source/geometries/Next100FieldCage.cc b/source/geometries/Next100FieldCage.cc
@@ -455,6 +455,16 @@ void Next100FieldCage::BuildCathode()
                                          cathode_grid_logic,  "CATHODE_GRID", mother_logic_,
                                          false, 0, false);
 
+      // Add optical surface
+      G4OpticalSurface* gas_mesh_opsur = new G4OpticalSurface("GAS_CATHODE_MESH_OPSURF");
+      gas_mesh_opsur->SetType(dielectric_metal);
+      gas_mesh_opsur->SetModel(unified);
+      gas_mesh_opsur->SetFinish(ground);
+      gas_mesh_opsur->SetSigmaAlpha(0.0);
+      gas_mesh_opsur->SetMaterialPropertiesTable(opticalprops::Steel());
+      new G4LogicalSkinSurface("GAS_CATHODE_MESH_OPSURF",
+                              cathode_grid_logic, gas_mesh_opsur);
+
   }
 
   // Cathode ring vertex generator
@@ -685,6 +695,15 @@ void Next100FieldCage::BuildELRegion()
     // Place GXe hexagons in the disk to make the mesh
     PlaceHexagons(n_hex, el_mesh_diam_, grid_thickn_, el_grid_logic, el_hex_logic, gate_int_diam_);
 
+    // Add optical surface
+    G4OpticalSurface* gas_mesh_opsur = new G4OpticalSurface("GAS_EL_MESH_OPSURF");
+    gas_mesh_opsur->SetType(dielectric_metal);
+    gas_mesh_opsur->SetModel(unified);
+    gas_mesh_opsur->SetFinish(ground);
+    gas_mesh_opsur->SetSigmaAlpha(0.0);
+    gas_mesh_opsur->SetMaterialPropertiesTable(opticalprops::Steel());
+    new G4LogicalSkinSurface("GAS_EL_MESH_OPSURF",
+                             el_grid_logic, gas_mesh_opsur);
 
   }
 

diff --git a/source/materials/OpticalMaterialProperties.cc b/source/materials/OpticalMaterialProperties.cc
@@ -1625,7 +1625,53 @@ namespace opticalprops {
     return mpt;
   }
 
+  // Copper Optical Properties Table
+  G4MaterialPropertiesTable * Copper()
+  {
+       G4MaterialPropertiesTable* mpt = new G4MaterialPropertiesTable();
+
+      // Reflectivity
+      std::vector<G4double> refl_energies = {
+              optPhotMinE_, hc_ / (700. * nm), hc_ / (650. * nm),
+                            hc_ / (600. * nm), hc_ / (500. * nm),
+                            hc_ / (400. * nm), hc_ / (300. * nm),
+                            hc_ / (170. * nm), optPhotMaxE_ };
+
+      // We assume a reflectivity of the copper of 20% at VUV
+      // Measurements may be required to update these values
+      // Visible spectrum taken from: E. Hecht, Optics, 5th edn., Pg 142, Fig 4.69
+      std::vector<G4double> reflectivities = { 0.90, 0.90, 0.70, 0.60, 0.40, 0.35, 0.30, 0.20, 0.20};
+
+      // Add Properties
+      mpt->AddProperty("SPECULARLOBECONSTANT", {optPhotMinE_, optPhotMaxE_}, {0., 0.});
+      mpt->AddProperty("SPECULARSPIKECONSTANT",{optPhotMinE_, optPhotMaxE_}, {0., 0.});
+      mpt->AddProperty("BACKSCATTERCONSTANT",  {optPhotMinE_, optPhotMaxE_}, {0., 0.});
+      mpt->AddProperty("REFLECTIVITY", refl_energies, reflectivities);
+      return mpt;
+  }
 
+  // Stainles Steel Optical Properties Table
+  G4MaterialPropertiesTable * Steel()
+  {
+      G4MaterialPropertiesTable* mpt = new G4MaterialPropertiesTable();
+
+      // Reflectivity
+      std::vector<G4double> refl_energies = {
+              optPhotMinE_, hc_ / (500. * nm), hc_ / (350. * nm),
+                            hc_ / (300. * nm), hc_ / (170. * nm),  optPhotMaxE_ };
+
+      // We assume a reflectivity of the stainless steel of 20% at VUV
+      // Measurements may be required to update these values
+      // Visible spectrum taken from: https://doi.org/10.1063/1.331503
+      std::vector<G4double> reflectivities = { 0.60, 0.60, 0.50, 0.40, 0.20, 0.20};
+
+      // Add properties
+      mpt->AddProperty("SPECULARLOBECONSTANT", {optPhotMinE_, optPhotMaxE_}, {0., 0.});
+      mpt->AddProperty("SPECULARSPIKECONSTANT",{optPhotMinE_, optPhotMaxE_}, {0., 0.});
+      mpt->AddProperty("BACKSCATTERCONSTANT",  {optPhotMinE_, optPhotMaxE_}, {0., 0.});
+      mpt->AddProperty("REFLECTIVITY", refl_energies, reflectivities);
+      return mpt;
+  }
 
   /// Generic material, to be modifed by the user ///
   G4MaterialPropertiesTable* XXX()

diff --git a/source/materials/OpticalMaterialProperties.h b/source/materials/OpticalMaterialProperties.h
@@ -83,6 +83,10 @@ namespace opticalprops {
 
   G4MaterialPropertiesTable* PMMA();
 
+  G4MaterialPropertiesTable* Copper();
+
+  G4MaterialPropertiesTable* Steel();
+
   G4MaterialPropertiesTable* XXX();