Neumann, A.; Tamashevich, Y.; Ushakov, A.: Experimental and simulated dark current and beam loss studies for a SRF photo-injector of an ERL injector. In: Ralph Assmann [Ed.] : IPAC'23 : Proceedings of the 14th International Particle Accelerator Conference ; Venice, Italy from 7 to 12 May 2023Geneve: JACoW, 2023. - ISBN 978-3-95450-231-8, p. THPL044/1-4
Open Access Version
Abstract:
The Superconducting RF (SRF )photo-injector with the prototype 1.4 𝜆/2-cell Niobium cavity of the bERLinPro Energy Recovery Linac (ERL), recently renamed to SEALab, was tested and characterized in a dedicated beam test facility called Gunlab to analyze its performance for the ERL. After dismantling and refurbishing of the cavity, a small surface defect was found close to the cathode opening and by simulated reconstruction of the set-up it was demonstrated to be the main source of the dark current measured at Gunlab. Later, a method was found to remove that defect, but still the question remains, what amount of dark current is acceptable for an ERL injector, especially for the SRF systems? In this contribution, we show a fully 3D simulation based emulation of the dark current measurements in Gunlab and extrapolate the impact on the complete injector at bERLinPro (SEALab). Here, it can be shown, that besides a small meshed beam loss diagnostics, methods need to be found to determine the amount of field emitted current dumped into the SRF systems.