The V International Geant4 School was organized by the Instituto Nazionale di Fisica Nucleare (INFN) and took place at the Laboratori Nationali del Sud (LNS, in Catania (Sicily). More than 60 PhD students, young researchers and medical physicists working at universities, research institutes or hospitals coming from 17 nations attended the five days hands-on course.

Geant4 is a well-established simulation platform which is developed and maintained by the international Geant4 collaboration ( The software toolkit is based on the Monte Carlo method and uses object oriented programming in C++ to simulate the passage of particles through matter. Geant4 is applied in different research areas such as high energy physics, astrophysics, nuclear physics and medical physics.

The course was structured in theoretical and practical modules. All participants were asked to bring their own laptop equipped with an installation of the simulation software in order to run simulations during the practical sessions. However, a convenient alternative was to use a pre-configured virtual machine with a Linux operating system (CentOS) and ready-to-use Geant4 installation which was provided prior to the course.

The first and the second day’s lessons mainly focused on the introduction on the Monte Carlo method, the proper installation of the simulation software and all main aspects of the C++ programming language.

During the 3rd and 4th day we were trained how to define simulation geometries and primary particle sources, how to run and control the simulation via the user interface and how to extract information from the simulation (e.g. dose scoring). Many hands-on sessions gave us the opportunity to practice the coding ourselves. Provided with a code skeleton we were able to complete clearly structured simulation tasks that build upon one another. Thus we gradually proceeded towards more and more complex applications.

On the last day a special lesson was given on the Geant4-DNA project, an extension of the Geant4 toolkit dedicated to the simulations of biological damage induced by ionizing radiation at the nanometer scale.
A final exam tested and confirmed our learning achievements.

Snapshot of an example Simulation run

Snapshot of an example simulation run

Dipl.-Phys. S. Höfel

Lt. Medizinphysiker