Hadron therapy is an emerging technique for treating cancerous tumors using ion beams. The main therapeutic indications for this technique are treatments for radioresistant tumors and/or tumors located near organs at risk, as well as treatments for tumors in children. To further exploit the advantages of this technique, numerous research projects are being conducted worldwide to develop systems that monitor the path of ions and ensure that treatments are delivered as planned by treatment planning systems. The detection of prompt gamma rays (PG) emitted during nuclear reactions involving a fraction of the incident ions is one of the main techniques being studied. In parallel with the development of PG detection systems, Monte Carlo simulation tools (notably Geant4/GATE) are being developed to compare experimental data with theoretical predictions, as well as to design and optimize monitoring systems. Regarding the detection of prompt gamma rays for hadron therapy monitoring, a fast simulation tool for PG emission in a voxelized geometry has recently been developed by the CREATIS-IP2I collaboration: the vpgTLE module (voxelized prompt-gamma track length estimator). The aim of the proposed internship is to extend this modeling to neutrons, whose contribution is significant in proton therapy, and to other ions in order to address applications in helium and carbon ion therapy. The developments will be carried out in GATE 10 (C++ code and Python-based interfacing).