IPAC2019 - List of Authors (Malyshev, O.B.)

Paper	Title	Page
TUPMP051	MULTIPACTOR SUPPRESSION BY LASER ABLATION SURFACE ENGINEERING FOR SPACE APPLICATIONS	1365
	R. Valizadeh, A.N. Hannah, O.B. Malyshev, B.S. Sian STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom J.S. Colligon University of Huddersfield, Huddersfield, United Kingdom Y. Dan Hitachi High-Technologies Corp., Ibaraki-ken, Japan V.R. Dhanak The University of Liverpool, Liverpool, United Kingdom J. Mutch STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom B.S. Sian UMAN, Manchester, United Kingdom N. Sykes Micronanics Laser Solution Center, Didcot, United Kingdom
	Developing a surface with low Secondary Electron Yield (SEY) is one of the main ways of mitigating electron cloud and beam-induced electron multipacting in high-energy charged particle accelerators and space-borne RF equipment for communication purposes. In this study we report on the secondary electron yield (SEY) measured from silver coated aluminium alloy as-received and after laser ablation surface engineering (LASE). Analysis shows the SEY can be reduced by 43% using LASE. EDX and SEM analysis shows it is possible to reduce the SEY whilst maintaining the original surface composition.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP051
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPTS114	Electron Stimulated Desorption from Cryogenic NEG-Coated Surfaces	2193
SUSPFO135	use link to see paper's listing under its alternate paper code
	R. Sirvinskaite, M.D. Cropper Loughborough University, Loughborough, Leicestershire, United Kingdom A.N. Hannah, O.B. Malyshev, R. Valizadeh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom S. Wang USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Non-Evaporable Getter (NEG) coating has been used for years in many particle accelerators due to its advantages like evenly distributed pumping speed, low thermal outgassing, and low photon, electron and ion stimulated desorption yields. Although NEG coating has been tested at room temperatures intensively, there is little data on its behaviour at cryogenic temperatures. Tests in this environment are important for the Future Circular Collider (FCC) study and other accelerator facilities where the operational conditions of the beam screen are restricted to cryogenic temperatures. This work will provide some preliminary results on NEG properties at low temperatures, e.g. pumping speed and capacity, as well as its behaviour under electron bombardment, where electron stimulated desorption (ESD) yields will be calculated. The ternary Ti-Zr-V coating, deposited with dense and columnar structure, will be the first material to be tested at cryogenic temperatures in ASTeC Daresbury laboratory. The results were compared with the ones obtained at room temperature, offering an insight into the behaviour of NEG-coated cryogenic chambers when beam-induced effects are present.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS114
About •	paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB011	PVD Depostion of Nb₃Sn Thin Film on Copper Substrate from an Alloy Nb₃Sn Target	2818
	R. Valizadeh, S. Aliasghari, A.N. Hannah, O.B. Malyshev STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom K. Dawson, V.R. Dhanak The University of Liverpool, Liverpool, United Kingdom G.B.G. Stenning STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom D. Turner STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom D. Turner Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
	In this study we report on the PVD deposition of Nb₃Sn on Cu substrates with and without a thick Nb interlayer to produce Cu/Nb/Nb₃Sn and Cu/Nb₃Sn multilayer structures. The Nb₃Sn was sputtered directly from an alloy target at room and elevated temperatures. The dependence of the superconducting properties of the total structure on deposition parameters has been determined. The films have been characterized via SEM, XRD, EDX and SQUID magnetometer measurements. Analysis showed that the composition at both room and elevated temperature was within the desired stoichiometry of 24’25 at%. However, superconductivity was only observed for deposition at elevated temperature or post annealing at 650 °C. The critical temperature was determined to be in the range of 16.8 to 17.4 K. In the case of bilayer deposition, copper segregation from the interface all the way to the surface was observed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB011
About •	paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MULTIPACTOR SUPPRESSION BY LASER ABLATION SURFACE ENGINEERING FOR SPACE APPLICATIONS

1365

R. Valizadeh, A.N. Hannah, O.B. Malyshev, B.S. Sian
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
J.S. Colligon
University of Huddersfield, Huddersfield, United Kingdom
Y. Dan
Hitachi High-Technologies Corp., Ibaraki-ken, Japan
V.R. Dhanak
The University of Liverpool, Liverpool, United Kingdom
J. Mutch
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
B.S. Sian
UMAN, Manchester, United Kingdom
N. Sykes
Micronanics Laser Solution Center, Didcot, United Kingdom

Developing a surface with low Secondary Electron Yield (SEY) is one of the main ways of mitigating electron cloud and beam-induced electron multipacting in high-energy charged particle accelerators and space-borne RF equipment for communication purposes. In this study we report on the secondary electron yield (SEY) measured from silver coated aluminium alloy as-received and after laser ablation surface engineering (LASE). Analysis shows the SEY can be reduced by 43% using LASE. EDX and SEM analysis shows it is possible to reduce the SEY whilst maintaining the original surface composition.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP051

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

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

TUPTS114

Electron Stimulated Desorption from Cryogenic NEG-Coated Surfaces

2193

SUSPFO135

use link to see paper's listing under its alternate paper code

R. Sirvinskaite, M.D. Cropper
Loughborough University, Loughborough, Leicestershire, United Kingdom
A.N. Hannah, O.B. Malyshev, R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
S. Wang
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Non-Evaporable Getter (NEG) coating has been used for years in many particle accelerators due to its advantages like evenly distributed pumping speed, low thermal outgassing, and low photon, electron and ion stimulated desorption yields. Although NEG coating has been tested at room temperatures intensively, there is little data on its behaviour at cryogenic temperatures. Tests in this environment are important for the Future Circular Collider (FCC) study and other accelerator facilities where the operational conditions of the beam screen are restricted to cryogenic temperatures. This work will provide some preliminary results on NEG properties at low temperatures, e.g. pumping speed and capacity, as well as its behaviour under electron bombardment, where electron stimulated desorption (ESD) yields will be calculated. The ternary Ti-Zr-V coating, deposited with dense and columnar structure, will be the first material to be tested at cryogenic temperatures in ASTeC Daresbury laboratory. The results were compared with the ones obtained at room temperature, offering an insight into the behaviour of NEG-coated cryogenic chambers when beam-induced effects are present.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS114

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

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

WEPRB011

PVD Depostion of Nb₃Sn Thin Film on Copper Substrate from an Alloy Nb₃Sn Target

2818

R. Valizadeh, S. Aliasghari, A.N. Hannah, O.B. Malyshev
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
K. Dawson, V.R. Dhanak
The University of Liverpool, Liverpool, United Kingdom
G.B.G. Stenning
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
D. Turner
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
D. Turner
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom

In this study we report on the PVD deposition of Nb₃Sn on Cu substrates with and without a thick Nb interlayer to produce Cu/Nb/Nb₃Sn and Cu/Nb₃Sn multilayer structures. The Nb₃Sn was sputtered directly from an alloy target at room and elevated temperatures. The dependence of the superconducting properties of the total structure on deposition parameters has been determined. The films have been characterized via SEM, XRD, EDX and SQUID magnetometer measurements. Analysis showed that the composition at both room and elevated temperature was within the desired stoichiometry of 24’25 at%. However, superconductivity was only observed for deposition at elevated temperature or post annealing at 650 °C. The critical temperature was determined to be in the range of 16.8 to 17.4 K. In the case of bilayer deposition, copper segregation from the interface all the way to the surface was observed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB011

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

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