ICN-UNAM: fix layer 1 half-length to 525 cm (Ian/SD Table 16); revert absorber to Geometry 6 (Rext=290 const, step in Rmin)

Author: joseesquivel-hub

Detectors/Upgrades/ALICE3/MID/simulation/src/Detector.cxx

@@ -145,7 +145,7 @@ void Detector::createGeometry()
   if (standardRadius) {
     mLayers.resize(2);
     mLayers[0] = MIDLayer(0, GeometryTGeo::composeSymNameLayer(0), 301.f, 500.f);
-    mLayers[1] = MIDLayer(1, GeometryTGeo::composeSymNameLayer(1), 311.f, 520.f); // arbitrarily reduced to get multiple of 5.2f
+    mLayers[1] = MIDLayer(1, GeometryTGeo::composeSymNameLayer(1), 311.f, 525.f); // 10 modules x 52.5 cm = 525 cm — matches Ian ref. code and SD Table 16 (10.5 m)
   } else if (midParam.mLayout == o2::mi3::MIDLayout::SteppedLayout) {
     // Ian Perez Garcia design (ICN-UNAM) — tesis §3.4.7 Geometria 8
     // 11 cm gap from absorber outer face to MID layer

Detectors/Upgrades/ALICE3/Passive/src/Absorber.cxx

@@ -175,9 +175,8 @@ void Alice3Absorber::ConstructGeometry()
       absorings->DefineSection(17, -500, 201, 239);
       break;
     case o2::passive::DetLayout::SteppedAbsorber:
-      // Geometria 6 (Antonio/tesis): cara externa plana Rmax=290, escalon hacia adentro.
-      // Externas 45 cm (Rmin=245), central 70 cm (Rmin=220). ~4 lambda_int en ambas.
-      // Ref: Ian Perez Garcia DetectorConstruction.cc abs_thickness = {45., 70., 45.}
+      // Geometria 6 (Ian/tesis): Rext=290 constante, escalon en Rmin.
+      // Externas 45 cm (Rmin=245), central 70 cm (Rmin=220). Ref: Ian DetectorConstruction.cc abs_thickness={45,70,45}
       absorings->DefineSection(0, -500, 245, 290);
       absorings->DefineSection(1, -300, 245, 290);
       absorings->DefineSection(2, -300, 220, 290);