• M. Petrarca, E. Chevallay, A.E. Dabrowski, M. Divall Csatari, S. Döbert, D. Egger, V. Fedosseev, T. Lefèvre, R. Losito, O. Mete
  CERN, Geneva

The high charge PHIN photo in­jec­tor is stud­ied at CERN as an elec­tron source for the CLIC Test Fa­cil­i­ty (CTF3) drive beam as an al­ter­na­tive to the pre­sent thermion­ic gun. The ob­jec­tive of PHIN is to demon­strate the fea­si­bil­i­ty of a laser-based elec­tron source for CLIC. The photo in­jec­tor op­er­ates with a 2.5 cell, 3 GHz RF gun using a Cs2Te pho­to­cath­ode il­lu­mi­nat­ed by UV laser puls­es gen­er­at­ed by am­pli­fy­ing and fre­quen­cy qua­dru­pling the sig­nal from a Nd:YLF os­cil­la­tor run­ning at 1.5GHz. The chal­lenge is to gen­er­ate a beam struc­ture of 1908μbunch­es with 2.33nC perμbunch at 1.5GHz lead­ing to a high in­te­grat­ed train charge of 4446nC and nom­i­nal beam en­er­gy of 5.5MeV with cur­rent sta­bil­i­ty below 1%. In the pre­sent test stand, a seg­ment­ed beam dump has been im­ple­ment­ed al­low­ing a time re­solved mea­sure­ment of the en­er­gy and en­er­gy spread of the elec­tron beam. In this paper we re­port and dis­cuss the mea­sured trans­verse and lon­gi­tu­di­nal beam pa­ram­e­ters for both the full and time gated train of bunch­es, and the ob­tained pho­to­cath­ode quan­tum ef­fi­cien­cy. Laser point­ing and am­pli­tude sta­bil­i­ty re­sults are dis­cussed tak­ing into ac­count cor­re­la­tion be­tween laser and elec­tron beam.