Data-Model.md

@@ -34,6 +34,7 @@ The digit represents (or at least should) the real response of the straw tube. I
 | Type | Name | Description |
 | ------ | ------ | ------ |
 | std::string | det | Name of the volume where the energy deposit occurs. The reference geoemtry is *EDepSimGeometry* in the input edep-sim file |
+| int | did | detector id, i.e. unique id of straw tube |
 | double | x | X position of the digit evaluated as explained above |
 | double | y | Y position of the digit evaluated as explained above |
 | double | z | Z position of the digit evaluated as explained above |