TY - CONF AU - Ayvazyan, Valeri AU - Branlard, Julien AU - Christou, Chris AU - Honkavaara, Katja AU - Katalev, Valery AU - Kostin, Denis AU - Rönsch-Schulenburg, Juliane AU - Schaper, Lucas AU - Schmidt, Christian AU - Wiencek, Mateusz AU - Varol, Burcu TI - Reaching design electron energy at FLASH after linac upgrade CY - CERN Geneva PB - JACoW Publishing M1 - PUBDB-2025-00418 SN - 978-3-95450-219-6 SP - 328 - 330 PY - 2024 N1 - Literaturangaben; AB - The FLASH 2020+ project at DESY includes, among other modernizations, an increase of the electron beam energy. Two accelerator modules were replaced and the RF distribution of other modules was optimized. The limiting factors such as cavity breakdown and field emission were identified and measured through dedicated studies. At a later stage, based on these measurements, adjustments to the high-power distribution were proposed and the optimal operating point was demonstrated to achieve the design electron energy of 1.35 GeV with the nominal RF pulse length at FEL lasing conditions. After proper optimization and tuning of the low-level RF parameters, the linac successfully operated at maximum energy and delivered FEL radiation in the wavelength range below 3.2 nm. The measurement results as well as the achieved cavity gradients with energy gains are presented. T2 - 32nd Linear Accelerator Conference CY - 25 Aug 2024 - 30 Aug 2024, Chicago (USA) Y2 - 25 Aug 2024 - 30 Aug 2024 M2 - Chicago, USA KW - Accelerator Physics (Other) KW - mc4-technology - MC4: Technology (Other) KW - MC4.4 - MC4.4 Low level RF (Other) LB - PUB:(DE-HGF)8 ; PUB:(DE-HGF)7 DO - DOI:10.18429/JACOW-LINAC2024-TUPB003 UR - https://bib-pubdb1.desy.de/record/622607 ER -