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SRF2003 Show Abstract


Title Q-SLOPE ANALYSIS OF NIOBIUM SC RF CAVITIES
Type Poster materials / surface effects
Abstract Q-slope, which often appears at medium field or high field in Qo-Eacc excitation curves of superconducting RF cavities, is analysed by two models: global heating model and magnetic gap smearing model. The latter is newly proposed in this paper. Qo-Eacc excitation curves are nicely fitted overall by combination of these models. Only the global heating on the RF surface due to the poor thermal conductivity in superconducting state cannot explain fully the Q-slope in the high gradient. The band gap smearing due to the RF magnetic field brings exponential degradation behaviour when the Hc is degraded seriously. The Q-slope seen in chemical polished cavity seems to be caused by the lower Hc due to the magnetic field enhancement. The rough surface might enhance field and the resultant Hc looks to be lower.

List of authors...

Principle author first.

Last (Family) Name First Name (Initials only) Affiliation or Organization (abbreviations if possible)
Saito K KEK



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