Speaker
Description
The 19 MeV electron linear accelerator ELSA at CEA DAM operated as an IR‑FEL in the 1990s and is now a user facility that provides pulsed bremsstrahlung and Inverse Compton Scattering (ICS) X‑rays. Renovation of the facility is currently under way to improve system reliability. The 144 MHz photo‑injector gun is the key element for producing a low‑emittance beam for the ICS X‑ray source. While the refurbishment of the 144 MHz RF source has increased the photo‑injector’s reliability, the short lifetime of the photocathodes has become the facility’s weak point. A first step toward higher beam availability for users is to replace the Cs₃Sb photocathodes with Cs₂Te, which is known to have a longer lifetime. The drawback of this material is that it requires illumination with UV light, resulting in less laser energy available for photon‑to‑electron conversion compared with visible‑light operation. This paper will present the fabrication process, compare the two materials in terms of quantum efficiency and lifetime, and describe the laser‑system upgrades needed to maintain the same electron‑beam current.
| In which format do you inted to submit your paper? | Word |
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