|WEPFDV006||Activities at NCBJ Towards Development of the Future, Fully-Superconducting, XFEL-Type, RF Electron Gun||566|
Our group at NCBJ works on upgrade of 1.6-cell, SRF, XFEL-type injector in collaboration with DESY and other laboratories. The work is focused on preparation of lead-on-niobium photocathode, its positioning in the gun cavity and on the UV laser system for photocurrent excitation. RF focusing effect was used to minimize the predicted emittance and transverse size of accelerated e- beam. Following beam dynamics computation, it has been proposed that the photocathode be recessed 0.45 mm into the rear wall of the gun cavity. It helps focusing e- beam in its low-energy part. Preparation of sc cathodes of Pb layer on Nb plugs (*, **) is reported, aimed at reaching clean, planar and uniform Pb films. The laser system will consist of commercially available Pharos laser and a 4-th harmonic generator. A gaussian, 300 fs long, 257 nm in wavelength UV pulse will be transformed in time by a pulse stretcher/stacker and in space by pi-shaper. The planned optical system will generate cylindrical photoelectron bunch 2 - 30 ps long and 0.2 - 3 mm wide.
* J. Lorkiewicz et al., Vacuum 179 (2020) 109524
** R. Nietubyc et al., NIM A891 (2018) pp. 78-86
|Poster WEPFDV006 [2.014 MB]|
|DOI •||reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2021-WEPFDV006|
|About •||Received ※ 21 June 2021 — Accepted ※ 13 April 2022 — Issue date; ※ 03 May 2022|
|Cite •||reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)|