IPAC2016 - List of Authors (Pattalwar, S.M.)

Paper	Title	Page
WEPMB057	First Results of Magnetic Field Penetration Measurements on Multilayer S-I-S Structures	2245
	O.B. Malyshev, K.D. Dumbell, L. Gurran, N. Pattalwar, S.M. Pattalwar, R. Valizadeh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom A.V. Gurevich ODU, Norfolk, Virginia, USA L. Gurran Lancaster University, Lancaster, United Kingdom L. Gurran Cockcroft Institute, Lancaster University, Lancaster, United Kingdom O.B. Malyshev, S.M. Pattalwar, R. Valizadeh Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The performance of superconducting RF cavities made of bulk Nb is limited by a breakdown field of Bp=~200 mT, close to the superheating field for Nb. A potentially promising solution to enhance the breakdown field of the SRF cavities beyond the intrinsic limits of Nb is a multilayer coating suggested in [1]. In the simplest case, such a multilayer may be a superconductor-insulator-superconductor (S-I-S) coating, for example, bulk niobium (S) coated with a thin film of insulator (I) followed by a thin layer of another superconductor (S) which could be e.g. dirty niobium [2]. Here we report the first results of our measurements of field penetration in Nb thin films and Nb-AlN-Nb multilayer samples at 4.2 K using the magnetic field penetration facility designed, built and tested in ASTeC.
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WEPMB056	CVD Deposition of Nb Based Materials for SRF Cavities	2241
	P. Pizzol, P. Chalker, T. Heil The University of Liverpool, Liverpool, United Kingdom O.B. Malyshev, S.M. Pattalwar, R. Valizadeh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom G.B.G. Stenning STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Bulk niobium cavities are widely employed in particle accelerators to create high accelerating gradient despite their high material and operation cost. Advancements in technology have taken bulk niobium close to its theoretical operational limits, pushing the research to explore novel materials, such as niobium based alloys. Nitrides of niobium offer such an alternative, exhibiting a higher Tc compared to bulk niobium. Replacing then the niobium with a material with better thermal conductivity, such as copper, coated with thin films of nitrides in a multilayer S-I-S would lead to improved performance at reduced cost. Physical vapour deposition (PVD) is currently used to produce these coatings, but it suffers from lack of conformity. This issue can be resolved by using chemical vapour deposition (CVD), which is able to produce high quality coatings over surfaces with a high aspect ratio. This project explores the use of CVD techniques to deposit NbN thin films starting from their chlorinated precursors. The samples obtained are characterized via SEM, FIB, XRD, and EDX.
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Paper

Title

Page

First Results of Magnetic Field Penetration Measurements on Multilayer S-I-S Structures

2245

O.B. Malyshev, K.D. Dumbell, L. Gurran, N. Pattalwar, S.M. Pattalwar, R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
A.V. Gurevich
ODU, Norfolk, Virginia, USA
L. Gurran
Lancaster University, Lancaster, United Kingdom
L. Gurran
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
O.B. Malyshev, S.M. Pattalwar, R. Valizadeh
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The performance of superconducting RF cavities made of bulk Nb is limited by a breakdown field of Bp=~200 mT, close to the superheating field for Nb. A potentially promising solution to enhance the breakdown field of the SRF cavities beyond the intrinsic limits of Nb is a multilayer coating suggested in [1]. In the simplest case, such a multilayer may be a superconductor-insulator-superconductor (S-I-S) coating, for example, bulk niobium (S) coated with a thin film of insulator (I) followed by a thin layer of another superconductor (S) which could be e.g. dirty niobium [2]. Here we report the first results of our measurements of field penetration in Nb thin films and Nb-AlN-Nb multilayer samples at 4.2 K using the magnetic field penetration facility designed, built and tested in ASTeC.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMB056

CVD Deposition of Nb Based Materials for SRF Cavities

2241

P. Pizzol, P. Chalker, T. Heil
The University of Liverpool, Liverpool, United Kingdom
O.B. Malyshev, S.M. Pattalwar, R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
G.B.G. Stenning
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Bulk niobium cavities are widely employed in particle accelerators to create high accelerating gradient despite their high material and operation cost. Advancements in technology have taken bulk niobium close to its theoretical operational limits, pushing the research to explore novel materials, such as niobium based alloys. Nitrides of niobium offer such an alternative, exhibiting a higher Tc compared to bulk niobium. Replacing then the niobium with a material with better thermal conductivity, such as copper, coated with thin films of nitrides in a multilayer S-I-S would lead to improved performance at reduced cost. Physical vapour deposition (PVD) is currently used to produce these coatings, but it suffers from lack of conformity. This issue can be resolved by using chemical vapour deposition (CVD), which is able to produce high quality coatings over surfaces with a high aspect ratio. This project explores the use of CVD techniques to deposit NbN thin films starting from their chlorinated precursors. The samples obtained are characterized via SEM, FIB, XRD, and EDX.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)