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Magnesium diboride coated bulk niobium: a new approach to higher acceleration gradient.

ABSTRACT: Bulk niobium Superconducting Radio-Frequency cavities are a leading accelerator technology. Their performance is limited by the cavity loss and maximum acceleration gradient, which are negatively affected by vortex penetration into the superconductor when the peak magnetic field at the cavity wall surface exceeds the vortex penetration field (Hvp). It has been proposed that coating the inner wall of an SRF cavity with superconducting thin films increases Hvp. In this work, we utilized Nb ellipsoid to simulate an inverse SRF cavity and investigate the effect of coating it with magnesium diboride layer on the vortex penetration field. A significant enhancement of Hvp was observed. At 2.8?K, Hvp increased from 2100?Oe for an uncoated Nb ellipsoid to 2700?Oe for a Nb ellipsoid coated with ~200?nm thick MgB2 thin film. This finding creates a new route towards achieving higher acceleration gradient in SRF cavity accelerator beyond the theoretical limit of bulk Nb.

SUBMITTER: Tan T

PROVIDER: S-EPMC5075871 | biostudies-other | 2016 Oct

REPOSITORIES: biostudies-other

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Magnesium diboride coated bulk niobium: a new approach to higher acceleration gradient.

Tan Teng T Wolak M A MA Xi X X XX Tajima T T Civale L L

Scientific reports 20161024

Bulk niobium Superconducting Radio-Frequency cavities are a leading accelerator technology. Their performance is limited by the cavity loss and maximum acceleration gradient, which are negatively affected by vortex penetration into the superconductor when the peak magnetic field at the cavity wall surface exceeds the vortex penetration field (H<sub>vp</sub>). It has been proposed that coating the inner wall of an SRF cavity with superconducting thin films increases H<sub>vp</sub>. In this work, ...[more]

PMID: 27775087

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