SRF2019 - List of Keywords (laser)

Paper	Title	Other Keywords	Page
MOP004	Preparation of Pb-Photocathodes at National Centre for Nuclear Research in Poland – State of the Art	cathode, electron, plasma, gun	25
	J. Lorkiewicz, I. Cieślik, P.J. Czuma, A.M. Kosińska, R. Nietubyć NCBJ, Świerk/Otwock, Poland J.K. Sekutowicz DESY, Hamburg, Germany
	Funding: We are currently using a financial support within "PolFEL - Polish Free Electron Laser" cofounded by the European Regional Development Fund. R&D activities related to preparation of the superconducting Pb photocathode layer on niobium substrate are ongoing at the National Centre for Nuclear Research (NCBJ) in cooperation with DESY, HZDR, HZB, BNL and other research institutes. The activities are part of the R&D program at DESY for the cw-upgrade of E-XFEL and for the newly approved free electron laser facility PolFEL to be built and operated at NCBJ. The optimization results obtained for the lead deposition on niobium and smoothing of the coated layers are reported. The photocathodes samples were tested for their surface morphology, microstructure and quantum efficiency in terms of the impact on the operation of all-superconducting RF electron injector, proposed for both facilities.
	Poster MOP004 [1.446 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP004
About •	paper received ※ 23 June 2019 paper accepted ※ 29 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP014	Electroplating of Sn Film on Nb Substrate for Generating Nb₃Sn Thin Films and Post Laser Annealing	cavity, radio-frequency, electron, HOM	51
	Z. Sun, M. Liepe, T.E. Oseroff, R.D. Porter Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA T. Arias, A.B. Connolly, J.M. Scholtz, N. Sitaraman, M.O. Thompson Cornell University, Ithaca, New York, USA X. Deng University of Virginia, Charlottesville, Virginia, USA K.D. Dobson University of Delaware, Newark, Delaware, USA
	Controlling film quality of Nb₃Sn is critical to its SRF cavity performance. The state-of-the-art vapor diffusion approach for Nb₃Sn deposition observed surface roughness, thin grain regions, and misfit dislocations which negatively affect the RF performance. The Sn deficiency and non-uniformity at the nucleation stage of vapor deposition is believed to be the fundamental reason to cause these roughness and defects issues. Thus, we propose to pre-deposit a uniform Sn film on the Nb substrate, which is able to provide sufficient Sn source during the following heat treatment for Nb₃Sn nucleation and growth. Here, we demonstrated successful electrodeposition of a low-roughness, dendrite-free, excellent-adhesion Sn film on the Nb substrate. More importantly, we further achieved a uniform, low-roughness (Ra = 66 nm), pure-stoichiometric Nb₃Sn film through thermal treatment of this electroplated Sn film in the furnace. Additionally, we provide preliminary results of laser annealing as a post treatment for epitaxial grain growth and roughness reduction.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP014
About •	paper received ※ 22 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP009	Pulse Laser Annealing of Niobium Film on Copper for SRF Cavities	niobium, cavity, experiment, interface	848
	Y. Yang, X.Y. Lu, W.W. Tan, L. Xiao, D. Xie, L. Zhu PKU, Beijing, People’s Republic of China
	Thin film cavities were proposed as the most promis-ing next generation superconducting cavities. The chal-lenges are improving the surface superconducting per-formance and reducing defects of the coating film, which can be greatly solved by laser annealing. Laser annealing system has been set up in Peking University, and experi-ments with niobium thin film sample have been carried out. Superconducting performance and other properties of Nb/Cu samples before and after annealing were com-pared. Recrystallization happened and surface structure improved a lot according to the results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP009
About •	paper received ※ 22 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP029	Towards Real-time Data Processing using FPGA Technology for High-speed Data Acquisition System at MHz Repetition Rates	FPGA, detector, experiment, electron	905
	M. Bawatna, A. Arnold, J.-C. Deinert, B.W. Green, S. Kovalev HZDR, Dresden, Germany
	Accelerator-based light sources, in particular, those based on linear accelerators, are intrinsically less stable than lasers or other more conventional light sources because of their large scale. In order to achieve optimal data quality, the properties of each light pulse need to be detected and implemented into the analysis of each experiment. Such schemes are of particular advantage in 4th generation light sources based on superconducting radiofrequency (SRF) technology, since here the combination of pulse-resolved detection schemes with high-repetition-rate is particularly fruitful. Implementation of several different purpose-built CMOS linear array detector will enable to perform arrival-time measurements at MHz repetition rates. An architecture based on FPGA technology will allow an online analysis of the measured data at MHz repetition rate and will decrease the amount of data throughput and disk capacity for storing the data by orders of magnitude. In this contribution, we will outline how the pulse-resolved data acquisition scheme of the TELBE user facility shall be upgraded to allow operation at MHz repetition rates and sub-femtosecond timing precision.
	Poster THP029 [1.616 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP029
About •	paper received ※ 23 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP041	Impact of the Cu Substrate Surface Preparation on the Morphological, Superconductive and RF Properties of the Nb Superconductive Coatings	cavity, SRF, radiation, niobium	935
	C. Pira, E. Chyhyrynets INFN/LNL, Legnaro (PD), Italy C.Z. Antoine CEA-IRFU, Gif-sur-Yvette, France X. Jiang, S.B. Leith, M. Vogel University Siegen, Siegen, Germany A. Katasevs, J. Kaupužs, A. Medvids, P. Onufrijevs Riga Technical University, Riga, Latvia O. Kugeler HZB, Berlin, Germany O.B. Malyshev, R. Valizadeh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom R. Ries, E. Seiler Slovak Academy of Sciences, Institute of Electrical Engineering, Bratislava, Slovak Republic A. Sublet CERN, Meyrin, Switzerland
	Funding: This project has received funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No 730871. Nowadays, one of the main issues of the superconducting thin film resonant cavities is the Cu surface preparation. A better understanding of the impact of copper surface preparation on the morphological, superconductive (SC) and RF properties of the coating, is mandatory in order to improve the performances of superconducting cavities by coating techniques. ARIES H₂020 collaboration includes a specific work package (WP15) to study the influence of Cu surface polishing on the SRF performances of Nb coatings that involves a team of 8 research groups from 7 different countries. In the present work, a comparison of 4 different polishing processes for Cu (Tumbling, EP, SUBU, EP+SUBU) is presented through the evaluation of the SC and morphological properties of Nb thin film coated on Cu planar samples and QPR samples, polished with different procedures. Effects of laser annealing on Nb thin films have also been studied. Different surface characterizations have been applied: roughness measurements, SEM, EDS, XRD, AFM, and thermal and photo-stimulated exoelectrons measurements. SC properties were evaluated with PPMS, and QPR measurements will be carry out at HZB in the beginning of 2019.
	Poster THP041 [3.196 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP041
About •	paper received ※ 23 June 2019 paper accepted ※ 05 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOP004

Preparation of Pb-Photocathodes at National Centre for Nuclear Research in Poland – State of the Art

cathode, electron, plasma, gun

25

J. Lorkiewicz, I. Cieślik, P.J. Czuma, A.M. Kosińska, R. Nietubyć
NCBJ, Świerk/Otwock, Poland
J.K. Sekutowicz
DESY, Hamburg, Germany

Funding: We are currently using a financial support within "PolFEL - Polish Free Electron Laser" cofounded by the European Regional Development Fund.
R&D activities related to preparation of the superconducting Pb photocathode layer on niobium substrate are ongoing at the National Centre for Nuclear Research (NCBJ) in cooperation with DESY, HZDR, HZB, BNL and other research institutes. The activities are part of the R&D program at DESY for the cw-upgrade of E-XFEL and for the newly approved free electron laser facility PolFEL to be built and operated at NCBJ. The optimization results obtained for the lead deposition on niobium and smoothing of the coated layers are reported. The photocathodes samples were tested for their surface morphology, microstructure and quantum efficiency in terms of the impact on the operation of all-superconducting RF electron injector, proposed for both facilities.

Poster MOP004 [1.446 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP004

About •

paper received ※ 23 June 2019 paper accepted ※ 29 June 2019 issue date ※ 14 August 2019

Export •

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

MOP014

Electroplating of Sn Film on Nb Substrate for Generating Nb₃Sn Thin Films and Post Laser Annealing

cavity, radio-frequency, electron, HOM

51

Z. Sun, M. Liepe, T.E. Oseroff, R.D. Porter
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
T. Arias, A.B. Connolly, J.M. Scholtz, N. Sitaraman, M.O. Thompson
Cornell University, Ithaca, New York, USA
X. Deng
University of Virginia, Charlottesville, Virginia, USA
K.D. Dobson
University of Delaware, Newark, Delaware, USA

Controlling film quality of Nb₃Sn is critical to its SRF cavity performance. The state-of-the-art vapor diffusion approach for Nb₃Sn deposition observed surface roughness, thin grain regions, and misfit dislocations which negatively affect the RF performance. The Sn deficiency and non-uniformity at the nucleation stage of vapor deposition is believed to be the fundamental reason to cause these roughness and defects issues. Thus, we propose to pre-deposit a uniform Sn film on the Nb substrate, which is able to provide sufficient Sn source during the following heat treatment for Nb₃Sn nucleation and growth. Here, we demonstrated successful electrodeposition of a low-roughness, dendrite-free, excellent-adhesion Sn film on the Nb substrate. More importantly, we further achieved a uniform, low-roughness (Ra = 66 nm), pure-stoichiometric Nb₃Sn film through thermal treatment of this electroplated Sn film in the furnace. Additionally, we provide preliminary results of laser annealing as a post treatment for epitaxial grain growth and roughness reduction.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP014

About •

paper received ※ 22 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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

THP009

Pulse Laser Annealing of Niobium Film on Copper for SRF Cavities

niobium, cavity, experiment, interface

848

Y. Yang, X.Y. Lu, W.W. Tan, L. Xiao, D. Xie, L. Zhu
PKU, Beijing, People’s Republic of China

Thin film cavities were proposed as the most promis-ing next generation superconducting cavities. The chal-lenges are improving the surface superconducting per-formance and reducing defects of the coating film, which can be greatly solved by laser annealing. Laser annealing system has been set up in Peking University, and experi-ments with niobium thin film sample have been carried out. Superconducting performance and other properties of Nb/Cu samples before and after annealing were com-pared. Recrystallization happened and surface structure improved a lot according to the results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP009

About •

paper received ※ 22 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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

THP029

Towards Real-time Data Processing using FPGA Technology for High-speed Data Acquisition System at MHz Repetition Rates

FPGA, detector, experiment, electron

905

M. Bawatna, A. Arnold, J.-C. Deinert, B.W. Green, S. Kovalev
HZDR, Dresden, Germany

Accelerator-based light sources, in particular, those based on linear accelerators, are intrinsically less stable than lasers or other more conventional light sources because of their large scale. In order to achieve optimal data quality, the properties of each light pulse need to be detected and implemented into the analysis of each experiment. Such schemes are of particular advantage in 4th generation light sources based on superconducting radiofrequency (SRF) technology, since here the combination of pulse-resolved detection schemes with high-repetition-rate is particularly fruitful. Implementation of several different purpose-built CMOS linear array detector will enable to perform arrival-time measurements at MHz repetition rates. An architecture based on FPGA technology will allow an online analysis of the measured data at MHz repetition rate and will decrease the amount of data throughput and disk capacity for storing the data by orders of magnitude. In this contribution, we will outline how the pulse-resolved data acquisition scheme of the TELBE user facility shall be upgraded to allow operation at MHz repetition rates and sub-femtosecond timing precision.

Poster THP029 [1.616 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP029

About •

paper received ※ 23 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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

THP041

Impact of the Cu Substrate Surface Preparation on the Morphological, Superconductive and RF Properties of the Nb Superconductive Coatings

cavity, SRF, radiation, niobium

935

C. Pira, E. Chyhyrynets
INFN/LNL, Legnaro (PD), Italy
C.Z. Antoine
CEA-IRFU, Gif-sur-Yvette, France
X. Jiang, S.B. Leith, M. Vogel
University Siegen, Siegen, Germany
A. Katasevs, J. Kaupužs, A. Medvids, P. Onufrijevs
Riga Technical University, Riga, Latvia
O. Kugeler
HZB, Berlin, Germany
O.B. Malyshev, R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
R. Ries, E. Seiler
Slovak Academy of Sciences, Institute of Electrical Engineering, Bratislava, Slovak Republic
A. Sublet
CERN, Meyrin, Switzerland

Funding: This project has received funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No 730871.
Nowadays, one of the main issues of the superconducting thin film resonant cavities is the Cu surface preparation. A better understanding of the impact of copper surface preparation on the morphological, superconductive (SC) and RF properties of the coating, is mandatory in order to improve the performances of superconducting cavities by coating techniques. ARIES H₂020 collaboration includes a specific work package (WP15) to study the influence of Cu surface polishing on the SRF performances of Nb coatings that involves a team of 8 research groups from 7 different countries. In the present work, a comparison of 4 different polishing processes for Cu (Tumbling, EP, SUBU, EP+SUBU) is presented through the evaluation of the SC and morphological properties of Nb thin film coated on Cu planar samples and QPR samples, polished with different procedures. Effects of laser annealing on Nb thin films have also been studied. Different surface characterizations have been applied: roughness measurements, SEM, EDS, XRD, AFM, and thermal and photo-stimulated exoelectrons measurements. SC properties were evaluated with PPMS, and QPR measurements will be carry out at HZB in the beginning of 2019.

Poster THP041 [3.196 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP041

About •

paper received ※ 23 June 2019 paper accepted ※ 05 July 2019 issue date ※ 14 August 2019

Export •

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