Radio Frequency Magnetic Field Limits of Nb and ${\mathrm{Nb}}_3\mathrm{Sn}$

Journal Article · Tue Jul 21 00:00:00 EDT 2015 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.115.047001· OSTI ID:1198713

Posen, S.; Valles, N.; Liepe, M.

Superconducting radio frequency (srf) cavities, essential components of many large particle accelerators, rely on the metastable flux-free state of superconducting materials. In this Letter, we present results of experiments measuring the magnetic field limits of two srf materials, Nb and Nb₃Sn. Resonators made using these materials were probed using both high power rf pulses and dc magnetic fields. Nb, which is the current standard material for srf cavities in applications, was found to be limited by the superheating field H_sh when prepared using methods to avoid excessive rf dissipation at high fields. Nb₃Sn, which is a promising alternative material that is still in the early stages of development for srf purposes, was found to be limited between the onset field of metastability H_c1 and H_sh. Furthermore, analysis of the results shows that the limitation is consistent with nucleation of flux penetration at defects in the rf layer.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Grant/Contract Number: ER41628; AC02-07CH11359
• OSTI ID: 1198713
• Alternate ID(s): OSTI ID: 1235052
• Report Number(s): FERMILAB-PUB-15-548-TD; PRLTAO; 047001
• Journal Information: Physical Review Letters, Vol. 115, Issue 4; ISSN 0031-9007
• Publisher: American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
36 MATERIALS SCIENCE