Nb/sub 3/Sn coating of high purity Nb cavities
Superconducting Nb cavities fabricated from high purity sheet material or postpurified by solid state gettering with Y or Ti provide high field and Q/sub 0/ levels due to the thermal stabilization of defects. For accelerator applications especially at frequencies above 1 GHz the coating of such cavities with Nb/sub 3/Sn layers is challenging because of significantly reduced rf losses at operating temperatures of about 4.2 K. The authors have developed a modified vapor diffusion technique using specially constructed UHV furnaces to produce uniform Nb/sub 3/Sn layers on 1 and 3 GHz accelerator cavities without losing the high thermal conductivity of the Nb wall. In a first experiment with a single-cell 3 GHz cavity of medium Nb purity (RRR=156) the authors have achieved E/sub acc/=10 MV/m with an 0.6 ..mu..m thick Nb/sub 3/Sn layer. This is so far the highest accelerating field for our Nb/sub 3/Sn cavities but it is low compared to the 25 MV/m achieved in the same cavity before coating. Possible reasons for the reduced breakdown field for Nb/sub 3/Sn will be discussed on the basis of the local thermal breakdown model.
- Research Organization:
- 6996600
- OSTI ID:
- 6091088
- Report Number(s):
- CONF-880812-
- Journal Information:
- IEEE Trans. Magn.; (United States), Vol. 25:2; Conference: Applied superconductivity conference, San Francisco, CA, USA, 21 Aug 1988
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
36 MATERIALS SCIENCE
NIOBIUM BASE ALLOYS
THERMAL CONDUCTIVITY
SUPERCONDUCTING CAVITY RESONATORS
FABRICATION
TIN ALLOYS
ACCELERATORS
GETTERING
PROTECTIVE COATINGS
SOLID-STATE PLASMA
STABILIZATION
THERMAL CYCLING
THERMODYNAMIC MODEL
TITANIUM
YTTRIUM
ALLOYS
CAVITY RESONATORS
COATINGS
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
MATHEMATICAL MODELS
METALS
NIOBIUM ALLOYS
PARTICLE MODELS
PHYSICAL PROPERTIES
PLASMA
RESONATORS
STATISTICAL MODELS
SUPERCONDUCTING DEVICES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
420201* - Engineering- Cryogenic Equipment & Devices
360104 - Metals & Alloys- Physical Properties