A mini scanning device for profiling charged beams.

In this article, we present the development of a mini scanner device to characterize the full transverse spatial density of a charged particle beam using computed tomography. The profiler consists of a wire mounted on a linear translator that can rotate around the beam. Tests were performed on a millimeter electron beam with 200 eV energy and 100 nA intensity, which allowed us to control and monitor both beam focusing and deflection.

Electron-induced ionization and cationic fragmentations of the isolated molecule of 2,4-imidazolidinedione (hydantoin): a study of the relaxing path thresholds.

In this work, our new experimental setup has been used to study the ionization and fragmentation of a prebiotic molecule, hydantoin, by electron impact. Scanning of the incident electron energy allows the determination of the appearance thresholds of the cations. The vertical ionization potential was found to be in good agreement with previous data. Dissociation thresholds for the main fragmentation patterns were also measured. In parallel, thanks to quantum chemical calculations, reaction schemes compatible with the experimental results are given.