Thesis defense : Edgar Barlerin
The thesis work presented concerns the development of a mass spectrometer with a large acceptance, FRACAS, in the framework of the study of the fragmentation of 12C ions on targets of interest for hadrontherapy. The development of this device is motivated by the need to measure the double differential effective fragmentation cross sections for each isotope produced. It will consist of a beam monitor, a target, trajectographs placed on either side of a magnet and a time-of-flight wall.
A systematic study of FRACAS, based on Monte-Carlo Geant4 simulations, has been performed and the data analyzed with fragment identification algorithms developed in the framework of this thesis. These simulations showed the influence of the position and spatial resolution of the detectors on the fragment identification efficiencies. An optimal configuration of the device could be determined.
In parallel, two detectors, the beam monitor and the downstream trajectographs were developed. Simulations have allowed to determine an optimal gap thickness and track width for the beam monitor allowing a theoretical spatial resolution of about 200 μm. Experimental measurements at the LPC allowed to characterize the performances of the manufactured prototypes however they did not allow to determine their spatial resolution. A data collection campaign is thus planned in March 2021 at GANIL to carry out these measurements.