RP vis fix

building the romanpot to avoid adjacent surfaces that are shared. Putting the vacuum inside the aluminum instead of making a shell.

src/GenericDetectors/trackers/src/RomanPot_geo.cpp

@@ -104,12 +104,12 @@ static Ref_t build_detector(Detector& dtor, xml_h e, SensitiveDetector sens) {
   UnionSolid rp_chamber_tee_outer(rp_chamber_tee_outer1, rp_detector_vacuum_tube, rot2);
   UnionSolid rp_chamber_tee_inner1(rp_beam_vacuum_tube2, rp_detector_vacuum_tube2, rot1);
   UnionSolid rp_chamber_tee_inner(rp_chamber_tee_inner1, rp_detector_vacuum_tube2, rot2);
-  SubtractionSolid shell(rp_chamber_tee_outer,rp_chamber_tee_inner);
-  Volume           rp_chamber_vol("rp_chamber_walls_vol", shell, aluminum);
+  //SubtractionSolid shell(rp_chamber_tee_outer,rp_chamber_tee_inner);
+  Volume           rp_chamber_vol("rp_chamber_walls_vol", rp_chamber_tee_outer, aluminum);
   Volume           rp_vacuum_vol("rp_chamber_vacuum_vol", rp_chamber_tee_inner, vacuum);
 
   auto chamber_pv = assembly.placeVolume(rp_chamber_vol);
-  auto vacuum_pv  = assembly.placeVolume(rp_vacuum_vol);
+  auto vacuum_pv  = rp_chamber_vol.placeVolume(rp_vacuum_vol);
   vacuum_pv.addPhysVolID("element", 1);
   rp_chamber_vol.setVisAttributes(vis0.c_str());
   rp_vacuum_vol.setVisAttributes(dtor.invisible());