2021/09/16 by Tiziana Spina, Anna Grassellino, Spina, Tiziana +3 · 1 citation
Engineering · Physics and Astronomy · #Applied Physics (physics.app-ph) #FOS: Physical sciences #Magnetic confinement fusion research #Materials Science (cond-mat.mtrl-sci) #Muon and positron interactions and applications #Particle accelerators and beam dynamics #Superconducting Materials and Applications #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.2109.07961
openalex publication_date 2021/09/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Main focus of this study is the investigation of thermodynamics phenomena responsible for the High Field Q Slope (HFQS) in SRF cavities by Internal Friction (IF) measurement. Mechanical spectroscopy is, indeed, a well-established technique to study precipitate formations in BCC materials and several works on the effects of impurities as N and O on the Snoek peak have been published so far and will be taken as reference to explain the mechanisms behind the observed dissipation effects. Internal Friction measurements were performed in Belgium at IMCE on Nb rectangular shape samples with different RRR values prepared at Fermilab by using Electro Polishing (EP), N-doping and heat treatments in order to reproduce the same conditions during the standard treatments applied on bulk Nb SRF cavities. From IF spectra, the H trapping mechanism by interstitial atoms (N and O and/or vacancies, depending on the purity level, RRR) can be easily recognized leading to results that perfectly corroborate previous findings on Q-disease, HFQS and RRR phenomena.