SuperNEMO TrackingTK

description:	Falaise tracking plugin for SuperNEMO data reconstruction
Date:	2024-03-18
Authors:	Tomáš Križák Maros Petro Miroslav Macko François Mauger

Introduction

The TrackingTK package is a Falaise plugin which provides a tracking module able to run a specific tracking algorithm (called tracking driver) to identify clusters of Geiger cell hits in the SuperNEMO detector and fit associated charged particles' trajectories.

This package only works with Falaise version >= 5.1.1. It makes use of the new snemo::processing::base_tracking_driver class from which any tracking driver class should inherit.

A sntk::notracking::no_tracking_driver dummy class is provided to illustrate the integration of a tracking driver class in the sntk::tracking_module. It does not operate any tracking reconstruction and lets the TCD and TTD banks empty. However, it implements three mandatory following virtual methods in order to be usable as an embeded driver in the sntk::tracking_module :

• void _at_initialize(const datatools::properties & config_,
                      datatools::service_manage & services_) override;

  This method configures and initializes the internal working space of the tracking driver.

• void _at_reset() override;

  This method terminates and resets the internal working space of the tracking driver.

• int process_tracking(const snemo::processing::tracking_precluster_collection_type & preclusters_,
                       const base_tracking_driver::calo_hit_collection_type & calo_hits_,
                       snemo::datamodel::tracker_clustering_data & clustering_,
                       snemo::datamodel::tracker_trajectory_data & track_fitting_) override;

  This methods operates the tracking algorithm. It takes a vector of preclusters of Geiger hits as input data and possibly a list of calorimeter hits. Tracker preclusters as well as calorimeter hits are automatically extracted from the input CD bank. The method aims to fill the TCD and TTD banks with identified and measured tracks of charged particles (clusters and fitted trajectories).

The snemo::processing::tracking_precluster data structure is described in the Falaise snemo/processing/tracking_utils.h header. It corresponds to the tracker's input data used by any tracking driver to build TCD and TTD banks. These clusters are build from the CD bank using a pre-clustering algorithm which is able to identify sets of Geiger hits on each side of the tracking chamber and also to separate candidate prompt and delayed clusters.

This design allows people to enrich the TrackingTK package with additional tracking algorithms/drivers that implement specific reconstruction approaches (Legendre transform based, maximum likelihood based...).

Class layout

  Falaise                       Falaise
  +------------------+          +------------------------+
  | dpp::base_module |          | snemo::processing::    |
  +------------------+          |   base_tracking_driver |
            ^ [inherit]         +------------------------+
            |                                ^      ^
            |                       [inherit]|      |
            |                                |      |
TrackingTK  |                                |      |
+-----------+-----------+                    |      |
| sntk::tracking_module |                    |      |
+-----------------------+       TrackingTK   |      `--------.
| - driver              |--+-<> +------------+------------+  |
+-----------------------+  |    |  some_tracking_driver   |  |
                           |    +-------------------------+  |
                           |    | - _at_initialize(...)   |  |
                      [own]|    | - _at_reset()           |  |
                           |    | - process_tracking(...) |  |
                           |    +-------------------------+  |
                           |                   _____________.'
                           |                 .'
                           |    TrackingTK   |
                           +-<> +------------+------------+
                                |  other_tracking_driver  |
                                +-------------------------+
                                | - _at_initialize(...)   |
                                | - _at_reset()           |
                                | - process_tracking(...) |
                                +-------------------------+