Abstract ID: 5 Monte Carlo simulation studies on a beam monitor based on MPGD detectors for hadron therapy

Remarkable scientific and technological progress during the last years has led to the construction of accelerator based facilities dedicated to hadron therapy. This kind of technology requires precise and continuous control of position, intensity and shape of the ions or protons used to irradiate cancers. Patient safety, accelerator operation and dose delivery should be optimized by a real time monitoring of beam intensity and profile before and during the treatment, by using non-destructive, high spatial resolution detectors. The authors have studied, developed and initially tested a beam monitor based on Micro Pattern Gaseous Detectors (MPGDs) called TPC-GEM (TPG) detector, characterized by high spatial resolution and rate capability. Due to the low amount of material in the active volume, it is “not invasive”, therefore the beam characteristics are preserved, so minimizing the uncertainties on beam position, intensity, energy and stability. Computer simulation could be done as a preliminary step for analyzing the basic characteristics of a detector, and Monte Carlo simulation is one approach that can be established. For a better understanding of the first TPG prototype design, and its further improvements, several Monte Carlo simulations were performed. The aim of this presentation is to give an overview of the full and specific Monte Carlo simulation framework, including different tools (GEANT4, FLUKA/FLAIR, Garfield++, ANSYS and ROOT), developed in order to study in detail the interaction of a therapeutic proton beam with the detector sensitive volume in a typical hadron therapy environment and the performance of the chamber, especially for the calculation of the primary ionization, charge transport through the amplification stages and signal creation. The results obtained will be presented, as well as the future perspectives.