Design of an active Thomson parabola for the detection of ions accelerated by laser: numerical simulations and characterization of different solutions

Abstract This paper presents the development of a modulable and active Thomson parabola ion spectrometer designed to measure the energy spectra of multi-MeV ion species generated in laser–plasma interactions. The spectrometer features a flexible and reconfigurable design, with modular components tailored for easy adaptation to various experimental setups and rapid deployment. GEANT4-based optical simulations were employed to investigate several active detection schemes using scintillators, allowing us to evaluate their feasibility and to identify limitations, such as with direct scintillation readouts or scintillating fiber bundles. These simulations informed the design choices and highlighted the need for continued optimization. Although experimental validation under real conditions remains to be performed, this work lays the foundation for high-repetition-rate, active ion detection compatible with current and upcoming high-intensity laser facilities.