Implications of degenerate mode mixing in UK XFEL SC cavities

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Persistent URL	http://purl.org/net/epubs/work/66295807
Record Status	Checked
Record Id	66295807
Title	Implications of degenerate mode mixing in UK XFEL SC cavities
Contributors	Mr AJ Gilfellon (Cockcroft Inst., and Manchester Univ.) (Pr.Au.), Prof RM Jones (Cockcroft Inst., and Manchester Univ.) (Ed.), Mr AE Wheelhouse (STFC Daresbury Lab., and Cockcroft Inst.) (Ed.), Dr B Muratori (STFC Daresbury Lab., and Cockcroft Inst.) (Ed.), Prof PH Williams (STFC Daresbury Lab., and Cockcroft Inst.) (Ed.)
Abstract	The UK XFEL (United Kingdom X-ray Free Electron Laser) is a proposed accelerator facility that will use predominantly superconducting RF structures to accelerate and manipulate the transiting electron bunches. Deviations from design longitudinal length of these Niobium RF cavities, or cells within, caused by errors in manufacturing, fabrication tolerances, assembly and installation can lead to modes becoming frequency degenerate. This gives rise to mode mixing, whereby the component modes combine to form additive and subtractive field distributions. Here we look at the mixing of transverse magnetic (TM) modes and locate problematic combinations where field strength enhancements can lead to increased on-axis loss factors and dipole kick factors, both of which can have adverse effects on the beam emittance and energy.
Organisation	ASTeC , STFC
Keywords	Higher order modes , RF cavity design , HOMs
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Language	English (EN)

Type	Details	URI(s)	Local file(s)	Year
Paper In Conference Proceedings	In 17th International Particle Accelerator Conference (IPAC 26), Deauville, France, 15-22 May 2026, (2026).		WEP5088.pdf	2026