ghit : Hit information utilities

Table of Contents

• Introduction
• Visual model
• Components
• Examples
• Ownership and contacts

Geant4 step accumulation into a GEMC hit

Introduction

The ghit module provides a compact hit container (GHit) for storing step-by-step and aggregated information from detector simulations.

A GHit records per-step information unconditionally:

• global and local positions
• energy deposited (optionally scaled by detector-specific multipliers)
• global time
• track identity (PDG, track ID, parent track ID, parent PDG)
• track 3-momentum and total energy
• creator process name

Visual model

Steps with the same detector-cell identity and discriminator accumulate into one GHit. Step positions, times, energy deposits, and track metadata remain aligned by vector index, while steps in neighboring cells or with a different discriminator form separate hits.

Tracks and steps crossing a segmented sensitive detector

Derived values, such as total deposited energy and time extent, are calculated from the retained step vectors. Digitizers can therefore inspect either the raw step sequence or the summarized hit view.

Per-step vectors and derived GHit quantities

Components

• GHit : hit container that accumulates per-step vectors and provides lazy derived quantities.

Examples

The module ships with an example program:

• ghit_example.cc : constructs a GTouchable, creates a GHit, generates randomized test hits, and compares them using GHit::is_same_hit().

Ownership and contacts

Author: © Maurizio Ungaro
e-mail: ungar.nosp@m.o@jl.nosp@m.ab.or.nosp@m.g

Note

This module does not define verbosity levels because it does not introduce any classes derived from glogger. Logging in the provided example is performed using GLogger.