Propagation through calorimeter

[asalzburger]

This discussion item tracks the progress of the implementation of propagation in/through the calorimeter. Several items have to be followed up, they will be described in more detail below:

• VolumeMaterialMapping validation
• STEP extension for energy loss and covariance transport
• Navigation through cell-like geometry with intersection of cell center

VolumeMaterialMapping

Contributors:

@andiwand @Corentin-Allaire @asalzburger

As a first step, the volume material mapping should be validated, this can be done using the new calorimeter description in the OpenDataDetector (ODD).

1. The ODD DD4hep volumes have to be described as Acts::TrackingVolume objects and glued together into a wrapping tracking geometry
2. Comparison of material seen in DD4hep/Geant4 with Acts::TrackingVolume to be done using the MaterialValidation setup, if this is not yet fully suited, it will have to be updated

STEP extension validation

Contributors:

@andiwand @asalzburger

The STEP_Propagator technology of ATLAS has been in Acts re-implemented as an Extension to the Eigen stepper, driven by an Auctioneer

1. Review the design for eventual over-engineering
2. Check energy loss through dense material and compare to Geant4 using the ODD
3. Validate/Implement the covariance transport

Navigation through Calorimeter with cells

Contributors:

@andiwand @asalzburger @paulgessinger

The navigation setup for the Inner Tracker with its layer based navigation approach is not suitable for a Cell-based description. This needs to be adapted, potentially using the OOBB navigation prototype already available.