SRF2021 - List of Keywords (synchrotron)

Paper	Title	Other Keywords	Page
SUPCAV011	Third Harmonic Superconductive Cavity for Bunch Lengthening and Beam Lifetime Increase of Sirius Synchrotron Light Source	cavity, impedance, electron, beam-loading	37
	I. Carvalho de Almeida, M. Hoffmann Wallner, A. Pontes Barbosa Lima CNPEM, Campinas, SP, Brazil
	A passive third harmonic superconducting cavity is to be installed at Sirius’ 4th generation synchrotron light source in order to lengthen the bunches and improve beam lifetime, which is dominated by Touschek scattering. A study of optimal bunch lengthening is carried on by enforcing a flat potential well around the synchronous electron and the results are compared to the passive operation case for several shunt impedances and unloaded quality factors based on known operating cavities. To determine the new bunch shape due to beam loading and its length, a full consistent approach is followed by setting the harmonic voltage amplitude equal to the optimum value and calculating the required detune, harmonic phase and synchronous phase for an initial complex form factor, allowing the new distribution to be obtained by an iterative process. For each case analyzed, energy acceptance is obtained through the separatrix in the phase plane and the corresponding lifetime increase ratio is calculated. Input power required after the addition of the harmonic cavity is then estimated.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV011
About •	Received ※ 20 June 2021 — Accepted ※ 15 November 2021 — Issue date ※ 21 March 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTEV006	Synchrotron XPS Study of Niobium Treated with Nitrogen Infusion	niobium, vacuum, cavity, experiment	211
	A.L. Prudnikava, J. Knobloch, O. Kugeler, Y. Tamashevich HZB, Berlin, Germany V. Aristov, O. Molodtsova DESY, Hamburg, Germany S. Babenkov LIDYL, Gif sur Yvette, France A. Makarova FUB, Berlin, Germany D. Smirnov Technische Universität Dresden, Dresden, Germany
	Processing of niobium cavities with the so-called ni-trogen infusion treatment demonstrates the improve-ment of efficiency and no degradation of maximal accelerating gradients. However, the chemical compo-sition of the niobium surface and especially the role of nitrogen gas in this treatment has been the topic of many debates. While our study of the infused niobium using synchrotron X-ray Photoelectron Spectroscopy (XPS) showed modification of the surface sub-oxides surprisingly there was no evidence of nitrogen con-centration build up during the 120°C baking step, irre-spectively of N₂ supply. Noteworthy, that the niobium contamination with carbon and nitrogen took place during a prolonged high-temperature anneal even in a high vacuum condition (10-8-10^-9 mbar). Evidently, the amount of such contamination appears to play a key role in the final cavity performance
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPTEV006
About •	Received ※ 21 June 2021 — Revised ※ 13 July 2021 — Accepted ※ 19 August 2021 — Issue date ※ 05 September 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPFAV006	The Superconducting Radio Frequency System of Shenzhen Industrial Synchrotron Radiation Source FacilityRIAL SYNCHROTRON RADIATION SOURCE FACILITY	cavity, radiation, storage-ring, radio-frequency	392
	W. Ma, Y.B. Sun, N. Yuan Sun Yat-sen University, Zhuhai, Guangdong, People’s Republic of China G.M. Liu SSRF, Shanghai, People’s Republic of China L. Lu, L. Yang, Z.L. Zhang IMP/CAS, Lanzhou, People’s Republic of China
	Shenzhen industrial synchrotron radiation source is a 3 GeV synchrotron radiation diffraction-limited source. It consists of three parts, linear accelerator, booster, and storage ring. As a basic part of the storage ring, the superconducting radio frequency system provides energy for the beam to supplement the beam power loss caused by synchrotron radiation and higher-order modes, and provide the longitudinal bunch for the electron beam. The superconducting radio frequency cavity of the storage ring consists of two 500 MHz single-cell cavities and a third harmonic 1500 MHz double-cell cavity. This paper will introduce the superconducting cavity, radio frequency amplifier, and low-level radio frequency system in the Shenzhen industrial synchrotron radiation source facility.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPFAV006
About •	Received ※ 20 June 2021 — Revised ※ 16 August 2021 — Accepted ※ 21 August 2021 — Issue date ※ 26 November 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

Third Harmonic Superconductive Cavity for Bunch Lengthening and Beam Lifetime Increase of Sirius Synchrotron Light Source

cavity, impedance, electron, beam-loading

37

I. Carvalho de Almeida, M. Hoffmann Wallner, A. Pontes Barbosa Lima
CNPEM, Campinas, SP, Brazil

A passive third harmonic superconducting cavity is to be installed at Sirius’ 4th generation synchrotron light source in order to lengthen the bunches and improve beam lifetime, which is dominated by Touschek scattering. A study of optimal bunch lengthening is carried on by enforcing a flat potential well around the synchronous electron and the results are compared to the passive operation case for several shunt impedances and unloaded quality factors based on known operating cavities. To determine the new bunch shape due to beam loading and its length, a full consistent approach is followed by setting the harmonic voltage amplitude equal to the optimum value and calculating the required detune, harmonic phase and synchronous phase for an initial complex form factor, allowing the new distribution to be obtained by an iterative process. For each case analyzed, energy acceptance is obtained through the separatrix in the phase plane and the corresponding lifetime increase ratio is calculated. Input power required after the addition of the harmonic cavity is then estimated.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPCAV011

About •

Received ※ 20 June 2021 — Accepted ※ 15 November 2021 — Issue date ※ 21 March 2022

Cite •

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

MOPTEV006

Synchrotron XPS Study of Niobium Treated with Nitrogen Infusion

niobium, vacuum, cavity, experiment

211

A.L. Prudnikava, J. Knobloch, O. Kugeler, Y. Tamashevich
HZB, Berlin, Germany
V. Aristov, O. Molodtsova
DESY, Hamburg, Germany
S. Babenkov
LIDYL, Gif sur Yvette, France
A. Makarova
FUB, Berlin, Germany
D. Smirnov
Technische Universität Dresden, Dresden, Germany

Processing of niobium cavities with the so-called ni-trogen infusion treatment demonstrates the improve-ment of efficiency and no degradation of maximal accelerating gradients. However, the chemical compo-sition of the niobium surface and especially the role of nitrogen gas in this treatment has been the topic of many debates. While our study of the infused niobium using synchrotron X-ray Photoelectron Spectroscopy (XPS) showed modification of the surface sub-oxides surprisingly there was no evidence of nitrogen con-centration build up during the 120°C baking step, irre-spectively of N₂ supply. Noteworthy, that the niobium contamination with carbon and nitrogen took place during a prolonged high-temperature anneal even in a high vacuum condition (10-8-10^-9 mbar). Evidently, the amount of such contamination appears to play a key role in the final cavity performance

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPTEV006

About •

Received ※ 21 June 2021 — Revised ※ 13 July 2021 — Accepted ※ 19 August 2021 — Issue date ※ 05 September 2021

Cite •

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

TUPFAV006

The Superconducting Radio Frequency System of Shenzhen Industrial Synchrotron Radiation Source FacilityRIAL SYNCHROTRON RADIATION SOURCE FACILITY

cavity, radiation, storage-ring, radio-frequency

392

W. Ma, Y.B. Sun, N. Yuan
Sun Yat-sen University, Zhuhai, Guangdong, People’s Republic of China
G.M. Liu
SSRF, Shanghai, People’s Republic of China
L. Lu, L. Yang, Z.L. Zhang
IMP/CAS, Lanzhou, People’s Republic of China

Shenzhen industrial synchrotron radiation source is a 3 GeV synchrotron radiation diffraction-limited source. It consists of three parts, linear accelerator, booster, and storage ring. As a basic part of the storage ring, the superconducting radio frequency system provides energy for the beam to supplement the beam power loss caused by synchrotron radiation and higher-order modes, and provide the longitudinal bunch for the electron beam. The superconducting radio frequency cavity of the storage ring consists of two 500 MHz single-cell cavities and a third harmonic 1500 MHz double-cell cavity. This paper will introduce the superconducting cavity, radio frequency amplifier, and low-level radio frequency system in the Shenzhen industrial synchrotron radiation source facility.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPFAV006

About •

Received ※ 20 June 2021 — Revised ※ 16 August 2021 — Accepted ※ 21 August 2021 — Issue date ※ 26 November 2021

Cite •

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