List All Readout Channels

[vvolkl]

Looking for some advice: Is there a good, generic way to list all the possible readout channels of a detector? That is all sensitive volumes including segmentations. Example: I have defined a detector with readout:

<readout name="ECalBarrelPhiEta">
  <segmentation type="FCCSWGridPhiEta" grid_size_eta="0.01" phi_bins="704" offset_eta="-1.68024" offset_phi="-pi+(pi/704.)"/>
  <id>system:4,cryo:1,type:3,subtype:3,layer:8,eta:9,phi:10</id>
</readout>

and want (to add some noise for example) to create an exhaustive list of all cellIDs that Geant4 might deposit energy in.

I think it should be straightforward enough to iterate over sensitive DetElements, but to find all possible segmentation cells is a bit trickier; is there already some generic code to do that?

[MarkusFrankATcernch]

I am not aware of generic code to perform this. However, I can see the usefulness - in fact I would be interested in such code as soon as I start with the digitization package....

It is also not clear how do do this, unless your sensitive volume is read-out throughout; ie without taking into account possible dead zones around the edges, cut-outs etc. I think to really describe such segmentations taking into account such effects is more complex than our simple bit-field.

[MarkusFrankATcernch]

Hi Valentin,
I just remembered this. This command does not give you all readout channels, but at least all sensitive volumes together with their corresponding id decoding (x/y or eta/phi decoding not present):

$> geoPluginRun -input ../checkout/DDDetectors/compact/SiD.xml -volmgr \
-plugin DD4hep_VolumeDump -detector EcalBarrel -sensitive -volume_ids

(add -help for details about arguments)
Output is then something like this:

VolumeDump       INFO  001    EcalBarrel_42    (TGeoPgon)           VolID: system: 6 barrel: 0
VolumeDump       INFO  002      stave_0          (TGeoTrd2)         VolID: system: 6 barrel: 0 system: 6 barrel: 0 module: 1 
VolumeDump       INFO  003        layer1_0         (TGeoBBox)       VolID: system: 6 barrel: 0 system: 6 barrel: 0 module: 1 layer: 1 
VolumeDump       INFO  004          slice1_0         (TGeoBBox)          S  VolID: system: 6 barrel: 0 system: 6 barrel: 0 module: 1 layer: 1 slice: 1  (0x00208806) 
VolumeDump       INFO  004          slice2_1         (TGeoBBox)             VolID: system: 6 barrel: 0 system: 6 barrel: 0 module: 1 layer: 1 slice: 2 
VolumeDump       INFO  004          slice3_2         (TGeoBBox)             VolID: system: 6 barrel: 0 system: 6 barrel: 0 module: 1 layer: 1 slice: 3 
VolumeDump       INFO  004          slice4_3         (TGeoBBox)             VolID: system: 6 barrel: 0 system: 6 barrel: 0 module: 1 layer: 1 slice: 4 
VolumeDump       INFO  003        layer2_1         (TGeoBBox)       VolID: system: 6 barrel: 0 system: 6 barrel: 0 module: 1 layer: 2 
VolumeDump       INFO  004          slice1_0         (TGeoBBox)             VolID: system: 6 barrel: 0 system: 6 barrel: 0 module: 1 layer: 2 slice: 1 
VolumeDump       INFO  004          slice2_1         (TGeoBBox)             VolID: system: 6 barrel: 0 system: 6 barrel: 0 module: 1 layer: 2 slice: 2 
VolumeDump       INFO  004          slice3_2         (TGeoBBox)          S  VolID: system: 6 barrel: 0 system: 6 barrel: 0 module: 1 layer: 2 slice: 3  (0x00610806) 
VolumeDump       INFO  004          slice4_3         (TGeoBBox)             VolID: system: 6 barrel: 0 system: 6 barrel: 0 module: 1 layer: 2 slice: 4 
VolumeDump       INFO  004          slice5_4         (TGeoBBox)             VolID: system: 6 barrel: 0 system: 6 barrel: 0 module: 1 layer: 2 slice: 5 

Does this partially help you?

[vvolkl]

Sorry for the very late reply, this is actually very nice! I think we can close.