Dottorato in FISICA DEGLI ACCELERATORI

Titolo della tesi: Study of the transfer and matching line for a PWFA-driven FEL

Compact accelerator facilities development, providing high brightness beams, is one of the most challenging tasks in the field of next generation compact and cost affordable particle accelerators. Particular attention is given to plasma driven particle facilities due to their possibility to integrate high gradient accelerating plasma modules with a short wavelength Free Electron Laser. The EuPRAXIA (European Plasma Research Accelerator with eXcellence In Applications) preparatory phase aims at designing the world’s first accelerator facility based on advanced plasma wakefield techniques to deliver 1- 5 GeV high brightness beams as required for users applications. This project foresees the realization of a user facility based on both laser driven and beam driven plasma acceleration. For the beam-driven scenario the LNF-INFN laboratories in Frascati (Italy), with its EuPRAXIA@SPARC LAB projects, represents one of the pillars for the experimental activities. The thesis work, presented here, is in the framework of the EuPRAXIA@SPARC_LAB project and aims to demonstrate the feasibility of realizing a transport line for beams outgoing from the accelerating plasma module. At the end of the acceleration process one of the most prominent drawbacks consists of removing the depleted high-charge driver while preserving the main features of the accelerated witness bunch. This thesis responds to these requests by proposing, at the exit from the accelerating module, an alternative solution to conventional one. Indeed, an innovative array of active plasma lenses (APLs) at the exit of the plasma module aims to guarantee the transport of the witness without affecting its quality by removing, at same time, the high charge energy depleted driver bunch by means of a collimator. Thanks to the extraordinary tunability of the APLs, the proposed system is able to adapt to different energy beams demonstrating a high efficiency in the dumping of the driver bunch. These features and, in addition, the compactness of the entire solution, guarantee the implementation of APL based lines in a future structure based on plasma acceleration where compactness represents the main goal.