diff --git a/compact/definitions.xml b/compact/definitions.xml
index 9c2698447922866fb89b079984890dddc1885591..7f74152af6f01554247c30385d286c661b8c9bd8 100644
--- a/compact/definitions.xml
+++ b/compact/definitions.xml
@@ -218,7 +218,7 @@
</comment>
<constant name="ForwardRomanPot_ID" value="150"/>
- <constant name="ZDC_ID" value="160"/>
+ <constant name="ffi_ZDC_ID" value="160"/>
<comment>
=====================================
@@ -244,7 +244,7 @@
<constant name="cb_Solenoid_rmin" value="0.0 * cm"/> <comment> Central Barrel Solenoid Inner diameter </comment>
<constant name="cb_Solenoid_rmax" value="137.0 * cm"/> <comment> Central Barrel Solenoid Outer diameter </comment>
<constant name="cb_Solenoid_z" value="400.0 * cm"/>
- <constant name="cb_Solenoid_shift" value="0.0 * cm"/><comment> Central Barrel Solenoid Size in Z direction </comment>
+ <constant name="cb_Solenoid_shift" value="0.0 * cm"/> <comment> Central Barrel Solenoid Size in Z direction </comment>
<constant name="Solenoid_thickness" value="400*mm"/>
<constant name="Solenoid_rmin" value="2000.0*mm"/>
@@ -418,6 +418,47 @@
<constant name="HcalEndcapLayers" value="floor(HcalEndcapAvailThickness / HcalOneLayerThickness)"/>
<constant name="HcalEndcapThickness" value="HcalEndcapLayers * HcalOneLayerThickness"/>
+ <comment>
+ ----------------------
+ Zero Degree Parameters
+ ----------------------
+ </comment>
+ <comment> BeamLines: IP6 </comment>
+ <constant name="ffi_ZDC_x_pos" value="90.0 * cm"/>
+ <constant name="ffi_ZDC_y_pos" value="0.0 * cm"/>
+ <constant name="ffi_ZDC_z_pos" value="3800.0 * cm"/>
+ <constant name="ffi_ZDC_rotateX_angle" value="0.0 * rad"/>
+ <constant name="ffi_ZDC_rotateY_angle" value="-0.0125 * rad"/>
+ <constant name="ffi_ZDC_rotateZ_angle" value="0.0 * rad"/>
+
+ <comment> BeamLines: IP8 </comment>
+ <!--
+ <constant name="ffi_ZDC_x_pos" value="127.0 * cm"/>
+ <constant name="ffi_ZDC_y_pos" value="0.0 * cm"/>
+ <constant name="ffi_ZDC_z_pos" value="3600.0 * cm"/>
+ <constant name="ffi_ZDC_rotateX_angle" value="0.0 * rad"/>
+ <constant name="ffi_ZDC_rotateY_angle" value="-0.025 * rad"/>
+ <constant name="ffi_ZDC_rotateZ_angle" value="0.0 * rad"/>
+ -->
+
+ <comment> Global parameters </comment>
+ <constant name="ffi_ZDC_width" value="60.0 * cm"/>
+ <constant name="ffi_ZDC_thickness" value="200.0 * cm"/>
+ <comment> Original Global parameters </comment>
+ <!--
+ <constant name="ffi_ZDC_thickness" value="250.0 * cm"/>
+ -->
+ <constant name="ffi_ZDC_ECAL_thickness" value="30.0 * cm"/>
+ <constant name="ffi_ZDC_ECAL_inner_radius" value="0.0 * cm"/>
+ <constant name="ffi_ZDC_ECAL_outer_radius" value="60.0 * cm"/>
+ <constant name="ffi_ZDC_ECAL_width" value="5.0 * cm"/>
+ <constant name="ffi_ZDC_ECAL_gap" value="5.0 * mm"/>
+ <constant name="ffi_ZDC_ECAL_ntower" value="10"/>
+ <comment> Original number of towers parameter </comment>
+ <!--
+ <constant name="ffi_ZDC_ECAL_ntower" value="20"/>
+ -->
+
<comment>
-----------------------
Gaseous RICH Parameters
diff --git a/compact/display.xml b/compact/display.xml
index ae6af1bf18fd1819d37492fc0e8484eee122e111..7e5846d7c116a9978967203c3a11e04ea57205ac 100644
--- a/compact/display.xml
+++ b/compact/display.xml
@@ -48,7 +48,9 @@
<vis name="RICHVis" alpha="0.5" r="1" g="0" b="1" showDaughters="false"/>
<vis name="BeamPipeVis" alpha="1" r= "0.75" g="0.75" b="0.75" showDaughters="true" visible="true"/>
- <vis name="cb_SolenoidVis" alpha="0.4" r= "0.1" g="0.0" b="0.1" showDaughters="true" visible="true"/>
+ <vis name="cb_SolenoidVis" alpha="0.4" r= "0.1" g="0.0" b="0.1" showDaughters="true" visible="true"/>
+ <vis name="ffi_ZDCVis" alpha="0.1" r= "0.1" g="0.0" b="1.0" showDaughters="true" visible="true"/>
+ <vis name="ffi_ZDCmoduleVis" alpha="1.0" r= "0.1" g="1.0" b="0.9" showDaughters="true" visible="true"/>
<comment>
Deprecated colors.
diff --git a/compact/ffi_ZDC.xml b/compact/ffi_ZDC.xml
new file mode 100644
index 0000000000000000000000000000000000000000..36638f190574fc06417d756cfd44213bde496a88
--- /dev/null
+++ b/compact/ffi_ZDC.xml
@@ -0,0 +1,38 @@
+<lccdd>
+
+ <comment>Far Forward Ion Zero Degree Calorimeter</comment>
+
+ <define>
+ </define>
+
+ <limits>
+ </limits>
+
+ <regions>
+ </regions>
+
+ <display>
+ </display>
+
+ <detectors>
+ <detector id="ffi_ZDC_ID" name="ffi_ZDC" type="ffi_ZDC" readout="ffi_ZDC_Hits" vis="ffi_ZDCVis">
+ <position x="ffi_ZDC_x_pos" y="ffi_ZDC_y_pos" z="ffi_ZDC_z_pos"/>
+ <rotation x="ffi_ZDC_rotateX_angle" y="ffi_ZDC_rotateY_angle" z="ffi_ZDC_rotateZ_angle"/>
+ <dimensions x="ffi_ZDC_width" z="ffi_ZDC_thickness"/>
+ <module name="ffi_ZDC_ECAL_module" vis="ffi_ZDCmoduleVis" material="PbWO4" thickness="ffi_ZDC_ECAL_thickness" rmin="ffi_ZDC_ECAL_inner_radius" rmax="ffi_ZDC_ECAL_outer_radius" width="ffi_ZDC_ECAL_width" gap="ffi_ZDC_ECAL_gap" ntower="ffi_ZDC_ECAL_ntower"/>
+ </detector>
+ </detectors>
+
+ <readouts>
+ <readout name="ffi_ZDC_Hits">
+ <segmentation type="CartesianGridXY" grid_size_x="1.0*mm" grid_size_y="1.0*mm" />
+ <id>system:8,sector:6,module:6,x:32:-16,y:-16</id>
+ </readout>
+ </readouts>
+
+ <plugins>
+ </plugins>
+
+ <fields>
+ </fields>
+</lccdd>
diff --git a/reference_detector.xml b/reference_detector.xml
index eff07459f239503cc6059cf3198e298f6a60091c..db0a52b76c7796d6581f981be0b256404480359f 100644
--- a/reference_detector.xml
+++ b/reference_detector.xml
@@ -115,6 +115,7 @@
<include ref="compact/silicon_tracker.xml"/>
-->
<include ref="ip6/beampipe.xml"/>
+ <include ref="compact/ffi_ZDC.xml"/>
<include ref="compact/solenoid.xml"/>
<include ref="compact/ecal.xml"/>
<include ref="compact/hcal.xml"/>
diff --git a/src/ffi_ZDC.cpp b/src/ffi_ZDC.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..0ea018719bb7f4b31264b71ebae7fb322979daa7
--- /dev/null
+++ b/src/ffi_ZDC.cpp
@@ -0,0 +1,86 @@
+#include <XML/Helper.h>
+///////////////////////////////////////////
+// Far Forward Ion Zero Degree Calorimeter
+///////////////////////////////////////////
+
+using namespace std;
+using namespace dd4hep;
+
+static Ref_t createDetector(Detector& desc, xml_h e, SensitiveDetector sens)
+{
+ xml_det_t x_det = e;
+ string detName = x_det.nameStr();
+ int detID = x_det.id();
+
+ xml_dim_t dim = x_det.dimensions();
+ double Width = dim.x();
+ double Thickness = dim.z();
+
+ xml_dim_t pos = x_det.position();
+ xml_dim_t rot = x_det.rotation();
+
+ Material Vacuum = desc.material("Vacuum");
+
+ xml_comp_t mod = x_det.child(_Unicode(module));
+ string modName = mod.nameStr();
+ Material mPbWO4 = desc.material(mod.materialStr());
+ double mThickness = mod.attr<double>(_Unicode(thickness));
+ double mRmin = mod.attr<double>(_Unicode(rmin));
+ double mRmax = mod.attr<double>(_Unicode(rmax));
+ double mWidth = mod.attr<double>(_Unicode(width));
+ double mGap = mod.attr<double>(_Unicode(gap));
+ int mNTowers = mod.attr<double>(_Unicode(ntower));
+
+ // Create Global Volume
+ Box ffi_ZDC_GVol_Solid(Width * 0.5, Width * 0.5, Thickness * 0.5);
+ Volume detVol("ffi_ZDC_GVol_Logic", ffi_ZDC_GVol_Solid, Vacuum);
+ detVol.setVisAttributes(desc.visAttributes(x_det.visStr()));
+
+ // Construct Tower
+ // Single Module
+ Box ffi_ZDC_ECAL_Solid_Tower(mWidth * 0.5, mWidth * 0.5, mThickness * 0.5);
+ Volume modVol("ffi_ZDC_ECAL_Logic_Tower", ffi_ZDC_ECAL_Solid_Tower, mPbWO4);
+ modVol.setVisAttributes(desc.visAttributes(mod.visStr()));
+ sens.setType("calorimeter");
+ modVol.setSensitiveDetector(sens);
+
+ // Module Position
+ double mod_x = 0.0 * mm;
+ double mod_y = 0.0 * mm;
+ double mod_z = -1.0 * Thickness / 2.0 + mThickness / 2.0 + 2.0 * mm;
+
+ int k = -1;
+ // Place Modules
+ for (int j = 0; j < mNTowers; j++) {
+ if (j == 0)
+ mod_y = Width / 2.0 - mWidth / 2.0 - mGap;
+ else
+ mod_y -= (mWidth + mGap);
+
+ if (abs(mod_y + mWidth / 2.0) > Width / 2.0)
+ continue;
+
+ mod_x = Width / 2.0 - (mWidth + mGap) * 0.5;
+
+ for (int i = 0; i < mNTowers; i++) {
+ if (i > 0)
+ mod_x -= (mWidth + mGap);
+ if (abs(mod_x + mWidth / 2.0) > Width / 2.0)
+ continue;
+ k++;
+ string module_name = detName + _toString(k,"_ECAL_Phys_%d");
+ PlacedVolume pv_mod = detVol.placeVolume(modVol, Position(mod_x,mod_y,mod_z));
+ pv_mod.addPhysVolID("sector", 1).addPhysVolID("module",k);
+ }
+ }
+
+ DetElement det(detName, detID);
+ Volume motherVol = desc.pickMotherVolume(det);
+ Transform3D tr(RotationZYX(rot.z(), -rot.y(), rot.x()), Position(pos.x(), pos.y(), pos.z()));
+ PlacedVolume detPV = motherVol.placeVolume(detVol, tr);
+ detPV.addPhysVolID("system", detID);
+ det.setPlacement(detPV);
+ return det;
+}
+
+DECLARE_DETELEMENT(ffi_ZDC, createDetector)