First steps with Geant4

19 May 2025, 13:00 → 23 May 2025, 18:00 Europe/Zurich

593/R-010 - Salle 11 (CERN)

This course is meant for those interested to begin to use the Geant4 toolkit to create or improve applications for High Energy or Nuclear Physics detectors and other domains including medical imaging, particle therapy and the effects of radiation on electronics. It will be a hands-on tutorial based on Geant4 version 11.3.

Lectures will cover the key aspects of Geant4 from the basic building blocks for all applications through intermediate topics. Practical sessions will guide each participant to build an example Geant4 application that is progressively extended to demonstrate a realistic use case.

The course is intended for novices and those with limited familiarity with Geant4. Participants are expected to have a basic knowledge of C++.

We encourage participation in person for CERN, local and those who are able to travel.  Note that if you do not have a CERN affiliation or access card, we will need further information to enable access to the CERN site.

Participation via videoconference will also be possible, for a limited number to enable good followup for the exercises.

Registration 

Registration is now FULL. Please register in the Waiting List. If a place become available we will notify you.

Priority for seats is given to those involved in CERN experiments and projects.

Preinstallation of Geant4 is Required

Users must setup a desktop or laptop capable of running Geant4, equipped with an internet connection. Minimum required free disk space to install the Geant4 Virtual Machine is about 25 GB; the recommended amount of RAM is 4 GB or over.

The Geant4 Virtual Machine (see instructions) is the only supported installation of Geant4. Users must have this installed on their machine, to undertake the exercises in an environment which supports all necessary functionality. We will organise a dedicated Zoom session for those participants who face difficulties installing or have questions about it.

Users are encouraged to create an additional installation on their system with native compilers, to facilitate long-term use, if they are knowledgeable about their operating system (typically using Linux, macOS or Windows). Supported systems and C++ compilers for these are listed in the Geant4 Installation Guide. If you have questions about whether your machine is appropriate, or problems about installing Geant4, see the Geant4 Installation Guide, and/or the Geant4 Installation and Configuration Discussion Forum.

Pre-requisites: 

• Basic knowledge of the C++ language 
• Basic knowledge of Monte Carlo simulation techniques 
• Availability of a machine with Virtual Machine pre-installed

Objectives: 

• Acquire basic understanding of particle transport Monte Carlo
• Acquire basic knowledge and first experience in using the Geant4 simulation toolkit

Monday 19 May

14:00 → 15:30 Introduction

• scope and goal of this course
• a short introduction to Geant4
• introduction of some important Geant4 concepts such as run, event, track, etc.

Speaker: Mihaly Novak (CERN)

15:30 → 15:50 Break

15:50 → 17:50 Preliminaries

• introduction of our work environment (i.e. the virtual machine installation,
  demystification of Geant4 install and CMake configuration, etc.)
• recapitulation of some object oriented concept of C++ crucial for the course
  (such as interface and their usage)

Speaker: Mihaly Novak (CERN)

17:50 → 17:55 Adjourn

Tuesday 20 May

14:00 → 15:30 Detector Description

• introduction of the G4VUserDetectorConstruction interface
• introduction to the Geant4 geometry description
• introduction to the Geant4 material description

Speaker: Mihaly Novak (CERN)

15:30 → 15:50 Break

15:50 → 17:50 Implementation of the Detector-Construction of our application

We will develop the main of our application.
Then we will start to implement its mandatory components:
- first the DetectorConstruction, i.e. the detector geometry and material description

17:50 → 18:00 Adjourn

Wednesday 21 May

14:00 → 15:30 Completing the Detector-Construction implementation

Speaker: Mihaly Novak (CERN)

15:30 → 15:50 Break

15:50 → 17:50 Primary Particle Generation

Topics:
- a (very basic) look behind multi-threaded Geant4
- introduction of the G4VUserPrimaryGeneratorAction and usage
- introduction of G4VUserActionInitialization interface
- implementation of the primary generator of our application

17:50 → 18:00 Adjourn

Thursday 22 May

14:00 → 15:30 Complete the primary generator implementation

Speaker: Mihaly Novak (CERN)

15:30 → 15:50 Break

15:50 → 17:50 Introduction of some more Geant4 user actions

We will revisit the key Geant4 concepts (run, event, step) related to actions

Introduce of the Actions and the related Geant4 interfaces
- Stepping Action (G4UserSteppingAction),
- Event Action (G4UserEventAction),
- and RunAction G4UserRunAction,

Implement the remaining user actions of our application.

Speaker: Mihaly Novak (CERN)

17:50 → 18:00 Adjourn

Friday 23 May

14:00 → 15:30 Using UI commands to add flexibility to our application

• introduction to Geant4 UI commands
• implementing UI commands to allow us to change of the target material, thickness at run-time

Speaker: Mihaly Novak (CERN)

15:30 → 15:50 Break

15:50 → 17:50 Recap

Use the application we developed
- Compare the results with experimental data

Summary of the course and outlook

Speaker: Mihaly Novak (CERN)

17:50 → 18:00 Adjourn