Mg-based photocathodes are attractive for the production of high brightness electron beams for future FELs, plasma acceleration experiments and high brillance linear colliders due to their respectable quantum efficiency.
The aim of this paper is to investigate the photoelectron performances and the surface morphology of Mg-based thin films prepared by pulsed laser deposition (PLD) using excimer lasers with different pulse duration: ns, ps and fs.
XeCl excimer laser (λ=308 nm) with pulse duration of 30 ns and KrF excimer laser (λ=248 nm) with 5 ps and 450 fs pulse duration were used for growing Mg films onto Si and Cu substrates in ultrahigh vacuum of 10^-5 Pa at room temperature.
The photoelectron performances were tested in a DC photodiode cell. In order to increase the quantum efficiency, in situ laser cleaning treatments were applied to samples surface in order to remove oxidized or polluted layers.
Sacnning Electron Microscope (SEM) was used to characterize the morphology of the films deposited and the oxidation level of Mg was studied by Energy Dispersive X-Ray spectroscopy (EDX).
Comparison among Mg-based photocathodes prepared by ns, ps and fs PLD for the production of high brightness electron beams will be presented and discussed