IPAC2022 - List of Authors (Rossi, C.)

Paper	Title	Page
TUPOTK055	One Year of Operation of the New Wideband RF System of the Proton Synchrotron Booster	1344
	G.G. Gnemmi, S. Energico, M. Haase, M.M. Paoluzzi, C. Rossi CERN, Meyrin, Switzerland
	Within the LHC Injectors Upgrade project, the PS Booster(PSB) has been upgraded. Both the injection (160 MeV) and extraction (2 GeV) energies have been increased, bringing also changes in the injection beam revolution frequency, the maximum revolution frequency, and the beam intensity. To meet the requirements of the High Luminosity LHC a new RF system has been designed, based on the wideband frequency characteristics of Finemet® Magnetic Alloy and solid-state amplifiers. The wideband frequency response (1 MHz to 18 MHz) covers all the required frequency schemes in the PSB, allowing multi-harmonics operation. The system is based on a cellular configuration in which each cell provides a fraction of the total RF voltage. The new RF system has been installed in 3 locations replacing the old systems. The installation has been performed during 2019/2020, while the commissioning started later in 2020 and relevant results for the physics have been already observed. This paper describes the new RF chain, the results achieved and the issues that occurred during this year of operation, together with the changes made to the system to improve performance and reliability.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK055
About •	Received ※ 02 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 28 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOTK046	Improved Longitudinal Performance of the LHC Beam in the CERN PS	2165
	H. Damerau, V.D. Desquiens, A. Huschauer, A. Jibar, A. Lasheen, B. Mikulec, M. Morvillo, C. Rossi, B.J. Woolley CERN, Meyrin, Switzerland
	At the end of the 2018 run the intensity target for the High-Luminosity LHC (HL-LHC) had just been reached at extraction from the Proton Synchrotron (PS). In the framework of the LHC Injectors Upgrade (LIU) project additional RF improvements have been implemented during the 2019/2020 long shutdown (LS2), mainly impacting the impedance of the 10 MHz, 40 MHz, and 80 MHz RF systems. With the upgraded injection energy of 2 GeV (kinetic), also the intermediate plateau energy for RF manipulations has been increased. Following a campaign of beam studies throughout the 2021 run, a bunch intensity of up to 2.9·10¹¹ p/b in trains of 72 bunches is achieved with the required longitudinal beam quality, surpassing the LIU target of 2.6·10¹¹ p/b. The threshold of longitudinal quadrupolar coupled-bunch instabilities is increased during acceleration, but they are again observed at the flat-top. While dipolar coupled-bunch oscillations are well damped by a dedicated feedback system, the quadrupolar modes are suppressed by operating a 40 MHz system as an active higher-harmonic Landau cavity. The main commissioning steps are outlined, together with the key contributions to the improved beam performance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK046
About •	Received ※ 07 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 16 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FROXSP1	20-Year Collaboration on Synchrotron RF Between CERN and J-PARC	3130
	C. Ohmori J-PARC, KEK & JAEA, Ibaraki-ken, Japan M. Brucoli, M. Brugger, H. Damerau, S. Danzeca, M.M. Paoluzzi, C. Rossi CERN, Meyrin, Switzerland K. Hasegawa, Y. Morita, Y. Sugiyama, M. Yoshii KEK, Tokai, Ibaraki, Japan H. Okita, M.J. Shirakata, F. Tamura JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	KEK/J-PARC and CERN started the collaboration on the RF systems of Low Energy Ion Ring to use magnetic alloy loaded cavities in 2002 for heavy ion collision program at LHC. It was an exchange of our expertise on the wideband cavities and high-power solid-state amplifiers. This paper summarizes the 20-year collaboration which includes many synchrotrons of both facilities: J-PARC Rapid Cycling Synchrotron and Main Ring, CERN Proton Synchrotron, PS Booster, Antiproton Decelerator, Extra Low Energy Antiproton ring and MedAustron. By the improvements of cavity core using the magnetic annealing, field gradient of cavity and compactness were improved to fit the requirements for LHC Injector Upgrade (LIU)program. Radiation-hard and compact high-power solid-state amplifiers were also developed for LIU and future accelerator improvements.
	Slides FROXSP1 [8.210 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-FROXSP1
About •	Received ※ 07 June 2022 — Revised ※ 17 June 2022 — Accepted ※ 19 June 2022 — Issue date ※ 25 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

One Year of Operation of the New Wideband RF System of the Proton Synchrotron Booster

1344

G.G. Gnemmi, S. Energico, M. Haase, M.M. Paoluzzi, C. Rossi
CERN, Meyrin, Switzerland

Within the LHC Injectors Upgrade project, the PS Booster(PSB) has been upgraded. Both the injection (160 MeV) and extraction (2 GeV) energies have been increased, bringing also changes in the injection beam revolution frequency, the maximum revolution frequency, and the beam intensity. To meet the requirements of the High Luminosity LHC a new RF system has been designed, based on the wideband frequency characteristics of Finemet® Magnetic Alloy and solid-state amplifiers. The wideband frequency response (1 MHz to 18 MHz) covers all the required frequency schemes in the PSB, allowing multi-harmonics operation. The system is based on a cellular configuration in which each cell provides a fraction of the total RF voltage. The new RF system has been installed in 3 locations replacing the old systems. The installation has been performed during 2019/2020, while the commissioning started later in 2020 and relevant results for the physics have been already observed. This paper describes the new RF chain, the results achieved and the issues that occurred during this year of operation, together with the changes made to the system to improve performance and reliability.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK055

About •

Received ※ 02 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 28 June 2022

Cite •

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

WEPOTK046

Improved Longitudinal Performance of the LHC Beam in the CERN PS

2165

H. Damerau, V.D. Desquiens, A. Huschauer, A. Jibar, A. Lasheen, B. Mikulec, M. Morvillo, C. Rossi, B.J. Woolley
CERN, Meyrin, Switzerland

At the end of the 2018 run the intensity target for the High-Luminosity LHC (HL-LHC) had just been reached at extraction from the Proton Synchrotron (PS). In the framework of the LHC Injectors Upgrade (LIU) project additional RF improvements have been implemented during the 2019/2020 long shutdown (LS2), mainly impacting the impedance of the 10 MHz, 40 MHz, and 80 MHz RF systems. With the upgraded injection energy of 2 GeV (kinetic), also the intermediate plateau energy for RF manipulations has been increased. Following a campaign of beam studies throughout the 2021 run, a bunch intensity of up to 2.9·10¹¹ p/b in trains of 72 bunches is achieved with the required longitudinal beam quality, surpassing the LIU target of 2.6·10¹¹ p/b. The threshold of longitudinal quadrupolar coupled-bunch instabilities is increased during acceleration, but they are again observed at the flat-top. While dipolar coupled-bunch oscillations are well damped by a dedicated feedback system, the quadrupolar modes are suppressed by operating a 40 MHz system as an active higher-harmonic Landau cavity. The main commissioning steps are outlined, together with the key contributions to the improved beam performance.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK046

About •

Received ※ 07 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 16 June 2022

Cite •

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

FROXSP1

20-Year Collaboration on Synchrotron RF Between CERN and J-PARC

3130

C. Ohmori
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
M. Brucoli, M. Brugger, H. Damerau, S. Danzeca, M.M. Paoluzzi, C. Rossi
CERN, Meyrin, Switzerland
K. Hasegawa, Y. Morita, Y. Sugiyama, M. Yoshii
KEK, Tokai, Ibaraki, Japan
H. Okita, M.J. Shirakata, F. Tamura
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

KEK/J-PARC and CERN started the collaboration on the RF systems of Low Energy Ion Ring to use magnetic alloy loaded cavities in 2002 for heavy ion collision program at LHC. It was an exchange of our expertise on the wideband cavities and high-power solid-state amplifiers. This paper summarizes the 20-year collaboration which includes many synchrotrons of both facilities: J-PARC Rapid Cycling Synchrotron and Main Ring, CERN Proton Synchrotron, PS Booster, Antiproton Decelerator, Extra Low Energy Antiproton ring and MedAustron. By the improvements of cavity core using the magnetic annealing, field gradient of cavity and compactness were improved to fit the requirements for LHC Injector Upgrade (LIU)program. Radiation-hard and compact high-power solid-state amplifiers were also developed for LIU and future accelerator improvements.

Slides FROXSP1 [8.210 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-FROXSP1

About •

Received ※ 07 June 2022 — Revised ※ 17 June 2022 — Accepted ※ 19 June 2022 — Issue date ※ 25 June 2022

Cite •

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