AddDetDD4hep < LinearCollider

---+ Implementing a detector in DD4hep 

The way detector models are defined is quite different between Mokka and DD4hep. DD4hep provides representations of all TGeo shapes and means to place them in a hierarchy of detector elements with additional information, and this is the core feature of DD4hep. This wiki shows how one would add a detector, e.g. the ECal, in DD4hep.

%TOC%

---++ Prototype implementations in DD4hep 

These can be found in the =examples/= directory:

   * !CLICSiD (CLIC Silicon Detector CDR by C.Grefe) - contains the ECal parameters
   * ILDEx (ILD Detector Toy model by F. Gaede) - does not contain any ECal components

The !CLICSiD example in the Root's OGL viewer:

  <img src="%PUBURLPATH%/%WEB%/%TOPIC%/CLICSiD-TGeo.png" alt="CLICSiD-TGeo.png" width="600" height="360" />

---++ Implementing ECal in the ILD model

The !ILDEx example included with DD4hep will produce this:

<img src="%PUBURLPATH%/%WEB%/%TOPIC%/ILDExDet.png" alt="ILDExDet.png" width="614" height="402" />

As a first step, one can copy the ECal components from the !CLICSiD to the existing ILDEx model. I will call my new test detector !ILDxECal:

<verbatim>
cd ~/myDD4hep
cp -r /afs/phas.gla.ac.uk/data/ilc/software/DD4hep/examples/ILDEx ILDxECal
</verbatim>
Clean up its contents a bit
<verbatim>
cd  ILDxECal
rm -rf build bin/* lib/*
</verbatim>
and rename all ILDEx instances to !ILDxECal.

Use copy and paste to add to =compact/ILDxECal.xml= all relevant !EcalBarrel dimensions, materials, visualisation options and geometry definitions (%ICON{warning}% in the respective sections of the XML). First define:
<verbatim>
        <constant name="CaloSides" value="12"/>
        <constant name="EcalBarrel_rmin" value="126.50*cm"/>
        <constant name="EcalBarrel_zmax" value="176.50*cm"/>
</verbatim>
then in materials add
<verbatim>
        <material name="TungstenDens24">
            <D value="17.8" unit="g/cm3"/>
            <fraction n="0.93" ref="W"/>
            <fraction n="0.061" ref="Ni"/>
            <fraction n="0.009" ref="Fe"/>
        </material>
</verbatim>
then add some visualisation options
<verbatim>
        <vis name="EcalBarrelVis" alpha="1.0" r="0" g="0" b="0.3" showDaughters="true" visible="true"/>
        <vis name="EcalBarrelStaveVis" alpha="1.0" r="1" g="0.9" b="0.5" showDaughters="false" visible="true"/>
</verbatim>
Add now the !EcalBarrel geometry:
<verbatim>
        <detector id="6" name="EcalBarrel" type="EcalBarrel" readout="EcalBarrelHits" vis="EcalBarrelVis" calorimeterType="EM_BARREL">
            <comment>EM Calorimeter Barrel</comment>
            <comment> Copied by protopop@cern.ch from CLICSiD example </comment>
            <dimensions numsides="(int) CaloSides" rmin="EcalBarrel_rmin" z="EcalBarrel_zmax*2" />
            <staves vis="EcalBarrelStaveVis"/>
            <layer repeat="1">
                <slice material = "Silicon" thickness = "0.032*cm" sensitive = "yes" limits="cal_limits" />
                <slice material = "Copper"  thickness = "0.005*cm" />
                <slice material = "Kapton"  thickness = "0.030*cm" />
                <slice material = "Air"     thickness = "0.033*cm" />
            </layer>
            <layer repeat="20">
                <slice material = "TungstenDens24" thickness = "0.25*cm" />
                <slice material = "Air"     thickness = "0.025*cm" />
                <slice material = "Silicon" thickness = "0.032*cm" sensitive = "yes" limits="cal_limits" />
                <slice material = "Copper"  thickness = "0.005*cm" />
                <slice material = "Kapton"  thickness = "0.030*cm" />
                <slice material = "Air"     thickness = "0.033*cm" />
            </layer>
            <layer repeat="10">
                <slice material = "TungstenDens24" thickness = "0.5*cm" />
                <slice material = "Air"     thickness = "0.025*cm" />
		<slice material = "Silicon" thickness = "0.032*cm" sensitive = "yes" limits="cal_limits" />
                <slice material = "Copper"  thickness = "0.005*cm" />
                <slice material = "Kapton"  thickness = "0.030*cm" />
                <slice material = "Air"     thickness = "0.033*cm" />
            </layer>
        </detector>
</verbatim>
and its readout
<verbatim>
        <readout name="EcalBarrelHits">
            <segmentation type="CartesianGridXY" grid_size_x="3.5*cm" grid_size_y="3.5*cm" />
            <id>system:8,barrel:3,module:4,layer:6,slice:5,x:32:-16,y:-16</id>
        </readout>
</verbatim>

One will need the C++ code snippet that interprets the !BarellEcal XML data and expands the geometry:
<verbatim>
cd ~/myDD4hep
cp /afs/phas.gla.ac.uk/data/ilc/software/DD4hep/examples/CLICSiD/src/EcalBarrel_geo.cpp 
</verbatim>

Now one can build the new test detector:
<verbatim>
source /afs/phas.gla.ac.uk/data/ilc/software/ilcsoft/v01-17/init_ilcsoft.sh
source /afs/phas.gla.ac.uk/data/ilc/software/DD4hep/bin/thisdd4hep.sh 
cd ~/myDD4hep/ILDxECal/build
cmake ..
make -j install
cd ../
source bin/thisILDxECal.sh
./geoDisplay compact/ILDxECal.xml
</verbatim>
and one obtains this:

<img src="%PUBURLPATH%/%WEB%/%TOPIC%/ILDxECal.png" alt="ILDxECal.png" width="614" height="439" />

---++ ECal geometries

The ECal <!--Mokka (ILD, C++) and GeomConverter (SiD, Java)--> geometry parameters can be compared with the values from:

   * =ilcsoft/v01-17/gear/v01-03/example/gear_ILD_o1_v05.xml= or =gear_TGeoILD00.xml=
   * =ilcsoft/v01-17/Clupatra/v00-09-01/examples/gear_CLIC_CDR.xml=

---++ Troubleshooting

Make sure units are present when dimensions and parameters are set in the compact XML file: 
<verbatim>
<segmentation type="CartesianGridXY" grid_size_x="3.5*cm" grid_size_y="3.5*cm" />
</verbatim>
Attachments
Topic attachments
I	Attachment	History	Action	Size	Date	Who	Comment
png	CLICSiD-TGeo.png	r2 r1	manage	393.5 K	2014-06-03 - 15:46	DanProtopopescu	CLICSiD example in the Root's GL viewer
png	ILDExDet.png	r1	manage	142.5 K	2014-06-04 - 12:11	DanProtopopescu	Original ILDEx toy model
png	ILDxECal.png	r1	manage	31.4 K	2014-06-04 - 12:12	DanProtopopescu	ILDxECal, i.e. ILDEx with the Barrel ECal added
This topic: LinearCollider > WebHome > AddDetDD4hep
Topic revision: r6 - 2014-06-19 - DanProtopopescu