First Design Studies of a Nc Cw Rf Gun for European Xfel

RF regulation with superconducting cavities and beam operation using a frequency shifted cavity

“…This calls for a different mode of RF operation, namely continuous wave (CW). The feasibility of a CW upgrade of EuXFEL is currently considered and several R&D projects are being carried out at DESY, [6][7][8]. Since its early days as a demonstrator of SRF acceleratorbased FEL, FLASH continues to offer the opportunity to develop new techniques for SRF accelerators, which can be applied at FLASH and at XFEL.…”

Design studies of a continuous-wave normal conducting buncher for European X-ray Free Electron Laser

“…For possible future upgrade to operate the Eu-XFEL in a continuous wave (CW) or in a Long Pulse (LP) mode it requires a CW injector system. There are two types of CW electron guns under development for Eu-XFEL, the main option is the superconducting (SC) gun [3], and the backup option is a NC, Very High Frequency (VHF) gun similar to the APEX gun at LBNL [4,5].…”

“…The normal conducting VHF gun-based injector system is being studied at Photo Injector Test Facility at DESY Zeuthen site (PITZ) [5]. The proposed injector system comprises a 217 MHz VHF gun, a 1.3 GHz buncher, two solenoids and a SC linac module [4,5,6]. A schematic diagram of the proposed injector system is shown in Fig.…”

“…The buncher increases both the beam peak current and the beam energy before the SC linac. To match the higher VHF gun voltage compared to the APEX gun [5], simulations predict a higher buncher voltage of ~400 kV [6], which is 66% higher than APEX buncher.…”