Design of spectrometer energy measurement setups for the future EuPRAXIA@SPARC_LAB and SSRIP linacs

EuPRAXIA@SPARC_LAB is a FEL user-facility currently under construction at INFN-LNF in the framework of the EuPRAXIA collaboration. The electron beam will be accelerated to 1 GeV by an X-band RF linac followed by a plasma wakefield acceleration stage. This high-brightness linac requires diagnostic tools able to measure the beam parameters with high accuracy and resolution. To monitor the beam energy and its spread, magnetic dipoles and quadrupoles will be installed along the linac, together with viewing screens and CCD cameras. Macroparticle beam dynamics simulations were performed to determine the optimal energy measurement setup in terms of accuracy and resolution. Similar diagnostics evaluations were carried out for the spectrometer installed at the 100 MeV RF linac of the beam facility SSRIP (IFIN-HH, Romania), whose commissioning planned for 2026 will be performed by INFN-LNF in collaboration with IFIN-HH. Optics measurements were performed to characterize the resolution and magnification of the optical system foreseen to be used at EuPRAXIA@SPARC_LAB and SSRIP for beam energy monitoring.