RICH update

Add another set of plane mirrors for longer photon tracks. WIP status will be removed when we have a basic design that works for pions/kaons/protons.

src/ForwardRICH_geo.cpp

@@ -27,6 +27,10 @@ typedef ROOT::Math::XYPoint Point;
 // check if a square in a ring
 inline bool in_ring(const Point &pt, double side, double rmin, double rmax)
 {
+    if (pt.r() > rmax || pt.r() < rmin) {
+        return false;
+    }
+
     // check four corners
     std::vector<Point> pts {
         Point(pt.x() - side/2., pt.y() - side/2.),
@@ -35,7 +39,7 @@ inline bool in_ring(const Point &pt, double side, double rmin, double rmax)
         Point(pt.x() + side/2., pt.y() + side/2.),
     };
     for (auto &p : pts) {
-        if (p.r() > (rmax) || p.r() < (rmin)) {
+        if (p.r() > rmax || p.r() < rmin) {
             return false;
         }
     }
@@ -172,27 +176,41 @@ static Ref_t createDetector(Detector& desc, xml::Handle_t handle, SensitiveDetec
         auto focus = sl.attr<double>(_Unicode(focus));
         auto wphi = sl.attr<double>(_Unicode(phiw));
         auto rotZ = sl.attr<double>(_Unicode(rotz));
-        auto radius = sl.attr<double>(_Unicode(curve));
         auto mRmin = sl.attr<double>(_Unicode(rmin));
         auto mRmax = sl.attr<double>(_Unicode(rmax));
-
-        double mTheta1 = std::asin(mRmin/radius);
-        double mTheta2 = std::asin(mRmax/radius);
-        double rotY = -std::asin(focus/radius);
-        // mirror slice shape
-        // somehow geant4 does not support -wphi/2. to wphi/2., so additonal rotation in Z
-        Sphere mirShape(radius, radius + mThick, mTheta1, mTheta2, 0., wphi);
-        Volume mirVol(Form("mirror_v_dummy%d", imod), mirShape, mirMat);
+        double curve = 0.;
+        if (sl.hasAttr(_Unicode(curve))) {
+            curve = sl.attr<double>(_Unicode(curve));
+        }
+        // geometry of mirror slice
+        PlacedVolume mirPV;
+        Volume mirVol(Form("mirror_v_dummy%d", imod));
+        mirVol.setMaterial(mirMat);
         mirVol.setVisAttributes(desc.visAttributes(mir.visStr()));
-        // action is in a reverse order
-        Transform3D tr = Translation3D(0., 0., mirZ - halfLength)
-                       * RotationZ(rotZ)
-                       * RotationY(rotY)
-                       * Translation3D(0., 0., -radius)
-                       * RotationZ(-wphi/2.);
-        DetElement mirDE(det, Form("Mirror_DE%d", imod), imod);
-        auto mirPV = envVol.placeVolume(mirVol, tr);
+        // spherical mirror
+        if (curve > 0.) {
+            // somehow geant4 does not support -wphi/2. to wphi/2., so additonal rotation in Z
+            double mTheta1 = std::asin(mRmin/curve);
+            double mTheta2 = std::asin(mRmax/curve);
+            double rotY = -std::asin(focus/curve);
+            mirVol.setSolid(Sphere(curve, curve + mThick, mTheta1, mTheta2, 0., wphi));
+            // action is in a reverse order
+            Transform3D tr = Translation3D(0., 0., mirZ - halfLength)   // move for z position
+                           * RotationZ(rotZ)                            // rotate phi angle
+                           * RotationY(rotY)                            // rotate for focus point
+                           * Translation3D(0., 0., -curve)              // move spherical shell to origin
+                           * RotationZ(-wphi/2.);                       // center phi angle to 0. (-wphi/2., wphi/2.)
+            mirPV = envVol.placeVolume(mirVol, tr);
+        // plane mirror
+        } else {
+            mirVol.setSolid(Tube(mRmin, mRmax, mThick/2.0, 0., wphi));
+            Transform3D tr = Translation3D(0., 0., mirZ - halfLength)   // move for z position
+                           * RotationZ(rotZ)                            // rotate phi angle
+                           * RotationZ(-wphi/2.);                       // center phi angle to 0. (-wphi/2., wphi/2.)
+            mirPV =envVol.placeVolume(mirVol, tr);
+        }
         mirPV.addPhysVolID("layer", ilayer).addPhysVolID("module", imod);
+        DetElement mirDE(det, Form("Mirror_DE%d", imod), imod);
         mirDE.setPlacement(mirPV);
         SkinSurface mirSurfBorder(desc, mirDE, Form("RICHmirror%d", imod), mirSurf, mirVol);
         mirSurfBorder.isValid();