diff --git a/compact/definitions.xml b/compact/definitions.xml
index d52994d6e32cc2daa293963423dcb78ac4215263..80e58e2824fb5882f63a4aa1cd70c22f313eb1de 100644
--- a/compact/definitions.xml
+++ b/compact/definitions.xml
@@ -205,6 +205,7 @@
<constant name="ForwardRICH_ID" value="121"/>
<constant name="ci_GEM_id" value="122"/>
<constant name="ForwardTRD_ID" value="123"/>
+ <constant name="GEMTrackerEndcap_ID" value="124"/>
<comment>
=====================================
diff --git a/compact/gem_tracker_endcap.xml b/compact/gem_tracker_endcap.xml
new file mode 100644
index 0000000000000000000000000000000000000000..516405f371769bc34e7a28abcfcc12d36b66d68a
--- /dev/null
+++ b/compact/gem_tracker_endcap.xml
@@ -0,0 +1,69 @@
+<lccdd>
+
+ <comment> Central Barrel Tracker Silicon </comment>
+
+ <define>
+ <comment> Si layer opiton </comment>
+ <constant name="GEMTrackerEndcapFoilX1" value="43.0 * mm"/>
+ <constant name="GEMTrackerEndcapFoilY" value="1020.0 * mm"/>
+ <constant name="GEMTrackerEndcapFoilOpeningAngle" value="30.1*degree"/>
+ <constant name="GEMTrackerEndcapFoilX2" value="2*GEMTrackerEndcapFoilY*tan(GEMTrackerEndcapFoilOpeningAngle/2.0) + GEMTrackerEndcapFoilX1"/>
+ <constant name="GEMTrackerEndcapFoil_rmin" value="GEMTrackerEndcapFoilX1/(tan(GEMTrackerEndcapFoilOpeningAngle/2.0)*2.0)"/>
+ <constant name="GEMTrackerEndcapFoil_rmax" value="(GEMTrackerEndcapFoilY+GEMTrackerEndcapFoil_rmin)/(cos(GEMTrackerEndcapFoilOpeningAngle/2.0))"/>
+ </define>
+
+ <limits>
+ </limits>
+
+ <regions>
+ </regions>
+
+ <display>
+ </display>
+
+ <detectors>
+ <detector
+ id="GEMTrackerEndcap_ID"
+ name="GEMTrackerEndcap"
+ type="refdet_GEMTrackerEndcap"
+ readout="GEMTrackerEndcapHits"
+ vis="Argonne_Red"
+ reflect="false">
+ <module name="GEMModule1" vis="Argonne_Process_Blue">
+ <trd x1="GEMTrackerEndcapFoilX1/2.0" x2="GEMTrackerEndcapFoilX2/2.0" z="GEMTrackerEndcapFoilY/2"/>
+ <comment> Going from HV side to readout side</comment>
+ <module_component thickness="1.127 * mm" material="Mylar"/>
+ <module_component thickness="3*mm" material="Ar10CO2"/>
+ <module_component thickness="0.127 * mm" material="Mylar"/>
+ <module_component thickness="2*mm" material="Ar10CO2"/>
+ <module_component thickness="0.127 * mm" material="Mylar"/>
+ <module_component thickness="2*mm" material="Ar10CO2"/>
+ <module_component thickness="0.127 * mm" material="Mylar"/>
+ <module_component thickness="2*mm" material="Ar10CO2"/>
+ <module_component thickness="0.175 * mm" material="Epoxy" sensitive="true" vis="Argonne_Process_Blue"/>
+ </module>
+ <layer id="1" >
+ <envelope vis="Argonne_Red"
+ rmin="GEMTrackerEndcapFoil_rmin" rmax="GEMTrackerEndcapFoil_rmax"
+ zstart="SiliconTrackerOuterBarrelLength/2+15*mm" length="30.0*mm" />
+ <ring r="GEMTrackerEndcapFoil_rmin+GEMTrackerEndcapFoilY/2.0"
+ zstart="SiliconTrackerOuterBarrelLength/2+20*mm"
+ nmodules="12" dz="10 * mm" module="GEMModule1" />
+ </layer>
+ </detector>
+
+ </detectors>
+
+ <readouts>
+ <readout name="GEMTrackerEndcapHits">
+ <segmentation type="CartesianGridXY" grid_size_x="1.0*mm" grid_size_y="1.0*mm" />
+ <id>system:8,barrel:2,layer:4,module:12,sensor:2,x:32:-16,y:-16</id>
+ </readout>
+ </readouts>
+
+ <plugins>
+ </plugins>
+
+ <fields>
+ </fields>
+</lccdd>
diff --git a/compact/materials.xml b/compact/materials.xml
index d8955f0bc9a4010381ca72f136c8eb2ee5950794..26ee6989605c1de6cc831d77186db58486cb01cb 100644
--- a/compact/materials.xml
+++ b/compact/materials.xml
@@ -192,5 +192,11 @@
<composite n="0.036" ref="C"/>
<composite n="0.073" ref="O"/>
</material>
+ <material name="Mylar">
+ <D type="density" value="1.39" unit="g/cm3" />
+ <fraction n="0.62502108" ref="C"/>
+ <fraction n="0.041960452" ref="H"/>
+ <fraction n="0.33301847" ref="O"/>
+ </material>
</materials>
diff --git a/reference_detector.xml b/reference_detector.xml
index 6a31c0a191c1ed05a85efb2dfec820d74a1e3201..99b3e96684b1297108ef828e0ed951c96060fae1 100644
--- a/reference_detector.xml
+++ b/reference_detector.xml
@@ -121,14 +121,15 @@
<include ref="compact/cb_CTD_Si.xml"/>
<include ref="compact/ce_mrich.xml"/>
<include ref="compact/ce_GEM.xml"/>
- <include ref="compact/ci_GEM.xml"/>
<include ref="compact/hcal.xml"/>
<include ref="compact/forward_trd.xml"/>
<include ref="compact/B0_tracker.xml"/>
<include ref="compact/forward_romanpot.xml"/>
<include ref="compact/forward_offM_tracker.xml"/>
<include ref="compact/vertex_tracker.xml"/>
+ <include ref="compact/gem_tracker_endcap.xml"/>
<!--
+ <include ref="compact/ci_GEM.xml"/>
<include ref="compact/cb_VTX_Barrel.xml"/>
<include ref="compact/ci_HCAL.xml"/>
<include ref="compact/forward_rich.xml"/>
diff --git a/src/TrapEndcapTracker_geo.cpp b/src/TrapEndcapTracker_geo.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..ea0c961ceffb7afc2bc913199c922306c724841d
--- /dev/null
+++ b/src/TrapEndcapTracker_geo.cpp
@@ -0,0 +1,140 @@
+//==========================================================================
+// AIDA Detector description implementation
+//--------------------------------------------------------------------------
+// Copyright (C) Organisation europeenne pour la Recherche nucleaire (CERN)
+// All rights reserved.
+//
+// For the licensing terms see $DD4hepINSTALL/LICENSE.
+// For the list of contributors see $DD4hepINSTALL/doc/CREDITS.
+//
+// Author : M.Frank
+//
+//==========================================================================
+//
+// Specialized generic detector constructor
+//
+//==========================================================================
+#include <map>
+#include "DD4hep/DetFactoryHelper.h"
+
+using namespace std;
+using namespace dd4hep;
+using namespace dd4hep::detail;
+
+static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector sens) {
+ typedef vector<PlacedVolume> Placements;
+ xml_det_t x_det = e;
+ Material vacuum = description.vacuum();
+ int det_id = x_det.id();
+ string det_name = x_det.nameStr();
+ bool reflect = x_det.reflect(false);
+ DetElement sdet(det_name, det_id);
+ Assembly assembly(det_name);
+ // Volume assembly (det_name,Box(10000,10000,10000),vacuum);
+ Volume motherVol = description.pickMotherVolume(sdet);
+ int m_id = 0, c_id = 0, n_sensor = 0;
+ map<string, Volume> modules;
+ map<string, Placements> sensitives;
+ PlacedVolume pv;
+
+ assembly.setVisAttributes(description.invisible());
+ sens.setType("tracker");
+
+ for (xml_coll_t mi(x_det, _U(module)); mi; ++mi, ++m_id) {
+ xml_comp_t x_mod = mi;
+ string m_nam = x_mod.nameStr();
+ xml_comp_t trd = x_mod.trd();
+ double posY;
+ double x1 = trd.x1();
+ double x2 = trd.x2();
+ double z = trd.z();
+ double y1, y2, total_thickness = 0.;
+ xml_coll_t ci(x_mod, _U(module_component));
+ for (ci.reset(), total_thickness = 0.0; ci; ++ci) total_thickness += xml_comp_t(ci).thickness();
+
+ y1 = y2 = total_thickness / 2;
+ Volume m_volume(m_nam, Trapezoid(x1, x2, y1, y2, z), vacuum);
+ m_volume.setVisAttributes(description.visAttributes(x_mod.visStr()));
+
+ for (ci.reset(), n_sensor = 1, c_id = 0, posY = -y1; ci; ++ci, ++c_id) {
+ xml_comp_t c = ci;
+ double c_thick = c.thickness();
+ Material c_mat = description.material(c.materialStr());
+ string c_name = _toString(c_id, "component%d");
+ Volume c_vol(c_name, Trapezoid(x1, x2, c_thick / 2e0, c_thick / 2e0, z), c_mat);
+
+ c_vol.setVisAttributes(description.visAttributes(c.visStr()));
+ pv = m_volume.placeVolume(c_vol, Position(0, posY + c_thick / 2, 0));
+ if (c.isSensitive()) {
+ sdet.check(n_sensor > 2,
+ "SiTrackerEndcap2::fromCompact: " + c_name + " Max of 2 modules allowed!");
+ pv.addPhysVolID("sensor", n_sensor);
+ c_vol.setSensitiveDetector(sens);
+ sensitives[m_nam].push_back(pv);
+ ++n_sensor;
+ }
+ posY += c_thick;
+ }
+ modules[m_nam] = m_volume;
+ }
+
+ for (xml_coll_t li(x_det, _U(layer)); li; ++li) {
+ xml_comp_t x_layer(li);
+ int l_id = x_layer.id();
+ int mod_num = 1;
+ for (xml_coll_t ri(x_layer, _U(ring)); ri; ++ri) {
+ xml_comp_t x_ring = ri;
+ double r = x_ring.r();
+ double phi0 = x_ring.phi0(0);
+ double zstart = x_ring.zstart();
+ double dz = x_ring.dz(0);
+ int nmodules = x_ring.nmodules();
+ string m_nam = x_ring.moduleStr();
+ Volume m_vol = modules[m_nam];
+ double iphi = 2 * M_PI / nmodules;
+ double phi = phi0;
+ Placements& sensVols = sensitives[m_nam];
+
+ for (int k = 0; k < nmodules; ++k) {
+ string m_base = _toString(l_id, "layer%d") + _toString(mod_num, "_module%d");
+ double x = -r * std::cos(phi);
+ double y = -r * std::sin(phi);
+ DetElement module(sdet, m_base + "_pos", det_id);
+ pv = assembly.placeVolume(m_vol, Transform3D(RotationZYX(0, -M_PI / 2 - phi, -M_PI / 2),
+ Position(x, y, zstart + dz)));
+ pv.addPhysVolID("barrel", 1).addPhysVolID("layer", l_id).addPhysVolID("module", mod_num);
+ module.setPlacement(pv);
+ for (size_t ic = 0; ic < sensVols.size(); ++ic) {
+ PlacedVolume sens_pv = sensVols[ic];
+ DetElement comp_elt(module, sens_pv.volume().name(), mod_num);
+ comp_elt.setPlacement(sens_pv);
+ }
+
+ if (reflect) {
+ pv =
+ assembly.placeVolume(m_vol, Transform3D(RotationZYX(M_PI, -M_PI / 2 - phi, -M_PI / 2),
+ Position(x, y, -zstart - dz)));
+ pv.addPhysVolID("barrel", 2).addPhysVolID("layer", l_id).addPhysVolID("module", mod_num);
+ DetElement r_module(sdet, m_base + "_neg", det_id);
+ r_module.setPlacement(pv);
+ for (size_t ic = 0; ic < sensVols.size(); ++ic) {
+ PlacedVolume sens_pv = sensVols[ic];
+ DetElement comp_elt(r_module, sens_pv.volume().name(), mod_num);
+ comp_elt.setPlacement(sens_pv);
+ }
+ }
+ dz = -dz;
+ phi += iphi;
+ ++mod_num;
+ }
+ }
+ }
+ pv = motherVol.placeVolume(assembly);
+ pv.addPhysVolID("system", det_id);
+ sdet.setPlacement(pv);
+ return sdet;
+}
+
+// clang-format off
+DECLARE_DETELEMENT(refdet_TrapEndcapTracker, create_detector)
+DECLARE_DETELEMENT(refdet_GEMTrackerEndcap, create_detector)