title: Assessment of Geant4 Prompt-Gamma Emission Yields in the Context of Proton Therapy Monitoring.
abstract: Monte Carlo tools have been long used to assist the research and development of solutions for proton therapy monitoring. The present work focuses on the prompt-gamma emission yields by comparing experimental data with the outcomes of the current version of Geant4 using all applicable proton inelastic models. For the case in study and using the binary cascade model, it was found that Geant4 overestimates the prompt-gamma emission yields by 40.2 ± 0.3%, even though it predicts the prompt-gamma profile length of the experimental profile accurately. In addition, the default implementations of all proton inelastic models show an overestimation in the number of prompt gammas emitted. Finally, a set of built-in options and physically sound Geant4 source code changes have been tested in order to try to improve the discrepancy observed. A satisfactory agreement was found when using the QMD model with a wave packet width equal to 1.3 fm(2).
authors: CNRS/IN2P3 UMR 5822, IPNL, Université de Lyon, Université Lyon 1 , Villeurbanne , France.
authors: Marco
authors: M
authors: Pinto
authors: CNRS/IN2P3 UMR 5822, IPNL, Université de Lyon, Université Lyon 1 , Villeurbanne , France.
authors: Denis
authors: D
authors: Dauvergne
authors: CREATIS, CNRS UMR 5220, INSERM U1044, INSA-Lyon, Centre Léon Bérard, Université de Lyon, Université Lyon 1 , Lyon , France.
authors: Nicolas
authors: N
authors: Freud
authors: CNRS/IN2P3 UMR 5822, IPNL, Université de Lyon, Université Lyon 1 , Villeurbanne , France.
authors: Jochen
authors: J
authors: Krimmer
authors: CREATIS, CNRS UMR 5220, INSERM U1044, INSA-Lyon, Centre Léon Bérard, Université de Lyon, Université Lyon 1 , Lyon , France.
authors: Jean M
authors: JM
authors: Létang
authors: CNRS/IN2P3 UMR 5822, IPNL, Université de Lyon, Université Lyon 1 , Villeurbanne , France.
authors: Etienne
authors: E
authors: Testa
keywords: Geant4; collimated camera; hadrontherapy; in-beam monitoring; nuclear fragmentation models; online monitoring; prompt gammas; proton therapy