Observation of Q-degradation in superconducting niobium cavities due to cooldown conditions
In the past two years several laboratories around the world have observed degradations of the Q-value of superconducting niobium cavities made from high purity niobium under certain cool-down conditions. Severe degradations have been reported for larger systems, when they were slowly cooled down or warmed up to temperatures < 200K.A systematic study of the influence of surface treatments like chemical polishing, anodic oxidation and heat-treatment as well as the cooling conditions on cavity performance of cavities manufactured from niobium of different purity has been conducted.Possible reductions of the Q-degradations by anodic oxidation have been explored. Results of these investigations are reported and changes in material parameters as caused by the degradation are discussed.
- Research Organization:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-84ER40150
- OSTI ID:
- 954182
- Report Number(s):
- CEBAF-PR-91-043; TRN: US201014%%1004
- Resource Relation:
- Conference: Paper compiled for 5th Workshop On RF Superconductivity
- Country of Publication:
- United States
- Language:
- English
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