DESIGN AND REALIZATION OF NEW SOLENOIDS FOR HIGH BRIGHTNESS ELECTRON BEAM INJECTORS

High-brightness, high-current electron beams are the
main requirements for fourth generation light sources such as free-electron lasers (FELs) [1], energy recovery Linacs (ERLs) [2] and high-energy linear colliders [3]. The most successful device for producing such beams is the Radio-Frequency photo-injector where a key element is the gun solenoid. Its main task is to limit the beam emittance growth in the first acceleration stages by imposing a spiraling motion to the beam.
This paper is focused on two magnets: the first one is the solenoid gun for the new photo-injector at INFN-LNF SPARC_LAB test facility [4, 5]. The design, the realization, and all the measurements performed at the factory and at LNF are shown. Moreover, the design of a solenoid for a novel C-band gun for CompactLight project is presented.
Both magnets have been designed with the goal to reach the same integrated field of the gun solenoid currently in-stalled at SPARC_LAB, with an integrated field quality of 5E-4 in a good field radius of 30 mm and 10 mm radius respectively for SPARC_LAB and CompactLight solenoid. This one is equipped with a bucking coil to limit the field on cathode that could led to an undesired emittance growth.