Moved beamline tracker to own files and inject into pipe

compact/far_backward/beamline_tracking.xml

@@ -0,0 +1,56 @@
+
+<lccdd>
+
+
+
+  <detectors>
+
+    <detector
+    id="BackwardsBeamline_ID"
+    type="BeamPipeTracking"
+    name="Pipe_tracker"
+    readout="BackwardsBeamlineHits">
+
+        <slice 
+        pipe_id="0"
+        grandmother="Pipe_Q1eR_to_B2BeR"
+        mother="Pipe_to_Q1eR_vacuum"
+        name="Pipe_to_Q1eR_tracker"/>
+
+        <slice
+        pipe_id="1"
+        grandmother="Pipe_Q1eR_to_B2BeR"
+        mother="Pipe_in_Q1eR_vacuum"
+        name="Pipe_in_Q1eR_tracker"/>
+
+        <slice
+        pipe_id="2"
+        grandmother="Pipe_Q1eR_to_B2BeR"
+        mother="Pipe_in_Q2eR_vacuum"
+        name="Pipe_in_Q2eR_tracker"/>
+
+        <slice
+        pipe_id="3"
+        grandmother="Pipe_Q1eR_to_B2BeR"
+        mother="Pipe_in_B2BeR_vacuum"
+        name="Pipe_in_B2BeR_tracker"/>
+
+        <slice
+        pipe_id="4"
+        grandmother="Pipe_Q3eR_to_B7eR"
+        mother="Pipe_in_Q3eR_vacuum"
+        name="Pipe_in_Q3eR_tracker"/>
+
+    </detector> 
+  </detectors>
+
+  <readouts>
+
+    <readout name="BackwardsBeamlineHits">
+      <segmentation type="NoSegmentation"/>
+      <id>system:8,pipe:8,end:2</id>
+    </readout>
+
+  </readouts>
+
+</lccdd>

compact/far_backward/extended.xml

@@ -2,7 +2,7 @@
 <!-- Copyright (C) 2023 Wouter Deconinck, Simon Gardner -->
 
 <lccdd>
-
+  
   <include ref="magnets.xml"/>
   <include ref="beamline_extension_hadron.xml"/>
   <include ref="beamline_extension_electron.xml"/>
@@ -13,4 +13,6 @@
   <!-- Luminosity detector -->
   <include ref="lumi.xml"/>
 
+  <include ref="beamline_tracking.xml"/>
+
 </lccdd>

compact/far_backward/magnets.xml

@@ -9,13 +9,10 @@
 
     <!-- Beam pipe going from Q1eR to B2BeR -->
     <detector
-    id="BackwardsBeamline_ID"
     name="Pipe_Q1eR_to_B2BeR"
     type="BeamPipeChain"
     wall_thickness="2*mm"
-    vis="BeamPipeVis"
-    readout="BackwardsBeamlineHits"
-    sensitive="false">
+    vis="BeamPipeVis">
       <pipe id="0" name="Pipe_to_Q1eR"
         xcenter="0" zcenter="(Center_Beampipe_End + Q1eR_CenterPosition+Q1eR_Length/2)/2"
         length="Center_Beampipe_End - (Q1eR_CenterPosition+Q1eR_Length/2)" theta="0"
@@ -127,13 +124,5 @@
 
   </fields>
 
-  <readouts>
-
-    <readout name="BackwardsBeamlineHits">
-      <segmentation type="NoSegmentation"/>
-      <id>system:8,pipe:8,end:2</id>
-    </readout>
-
-  </readouts>
 
 </lccdd>

src/BeamPipeTracking_geo.cpp

@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: LGPL-3.0-or-later
+// Copyright (C) 2024 Simon Gardner
+
+//==========================================================================
+//
+// Places a small sensitive disk of vacuum at the end of beam pipes
+//
+//==========================================================================
+
+#include "DD4hep/DetFactoryHelper.h"
+#include "DD4hep/Printout.h"
+#include "TMath.h"
+#include <XML/Helper.h>
+
+using namespace std;
+using namespace dd4hep;
+
+static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector sens) {
+
+
+  using namespace ROOT::Math;
+  xml_det_t x_det   = e;
+  string   det_name = x_det.nameStr();
+  int      det_id   = x_det.id();
+  Material m_Vacuum = description.material("Vacuum");
+  string   vis_name = dd4hep::getAttrOrDefault<std::string>(x_det, _Unicode(vis), "BeamPipeVis");
+
+  sens.setType("tracker");
+
+  DetElement sdet(det_name, det_id);
+  Assembly   assembly(det_name + "_assembly");
+
+  // Grab info for beamline magnets
+  for (xml_coll_t slice_coll(x_det, _Unicode(slice)); slice_coll; slice_coll++) { // pipes
+
+    string grandmotherName  = slice_coll.attr<string>(_Unicode(grandmother));
+    string motherName       = slice_coll.attr<string>(_Unicode(mother));
+    bool   detStart         = getAttrOrDefault<bool>(slice_coll, _Unicode(end), true);
+    int    pipe_id          = getAttrOrDefault<int> (slice_coll, _Unicode(pipe_id), 0);
+    string slice_name       = slice_coll.attr<string>(_Unicode(name));
+    DetElement mother       = description.detector(grandmotherName).child(motherName);
+
+    // Get the mother volume
+    Volume mother_vol = mother.volume();
+
+    // Get mother volume shape as cone segment
+    ConeSegment mother_shape = mother_vol.solid();
+
+    // Get the parameters of the mother volume
+    double rOuter1 = mother_shape.rMax1();
+    double rOuter2 = mother_shape.rMax2();
+    double length  = 2*mother_shape.dZ();
+
+    double sensitive_thickness = 0.1 * mm;
+
+    //Calculate R or cone after sensitive layer
+
+    double rEnd = rOuter2 - (rOuter2 - rOuter1) * sensitive_thickness / length;
+    double zPos = length / 2.0 - sensitive_thickness / 2.0;
+    if (detStart){
+      rEnd = rOuter1 - (rOuter1 - rOuter2) * sensitive_thickness / length;
+      zPos = -length / 2.0 + sensitive_thickness / 2.0;
+    }
+
+    ConeSegment s_start_disk(sensitive_thickness / 2, 0.0, rOuter2, 0.0, rEnd);
+    Volume v_start_disk("v_start_disk_" + motherName, s_start_disk, m_Vacuum);
+    v_start_disk.setSensitiveDetector(sens);
+
+    auto disk_placement = mother_vol.placeVolume(v_start_disk, Position(0.0, 0.0, zPos));
+    disk_placement.addPhysVolID("end",    detStart  );
+    disk_placement.addPhysVolID("pipe",   pipe_id   );
+    disk_placement.addPhysVolID("system", det_id    );
+
+    DetElement slice_element(sdet, slice_name, pipe_id);
+
+    slice_element.setPlacement(disk_placement);
+    description.declareParent(slice_name, mother);
+
+  }
+
+  auto pv_assembly = description.worldVolume().placeVolume(assembly, Position(0.0, 0.0, 0.0));
+  sdet.setPlacement(pv_assembly);
+
+  return sdet;
+}
+
+DECLARE_DETELEMENT(BeamPipeTracking, create_detector)