LINAC2022 - List of Authors (Bouly, F.)

Paper	Title	Page
MOPOPA15	Three Years of Operation of the SPIRAL2 SC LINAC- RF Feedback	98
	M. Di Giacomo, M. Aburas, P.-E. Bernaudin, O. Delahaye, A. Dubosq, A. Ghribi, J.-M. Lagniel, J.F. Leyge, G. Normand, A.K. Orduz, F. Pillon, L. Valentin GANIL, Caen, France F. Bouly LPSC, Grenoble Cedex, France S. Sube CEA-DRF-IRFU, France
	The superconducting LINAC of SPIRAL2 at the GANIL facility has been in operation since October 2019. The accelerator uses 12 low beta and 14 high beta supercon-ducting quarter wave cavities, cooled at 4°K, working at 88 MHz. The cavities are operated at a nominal gradient of 6.5 MV/m and are independently powered by a LLRF and a solid-state amplifier, protected by a circulator. Pro-ton and deuteron beam currents can reach 5 mA and beam loading perturbation is particularly strong on the first cavities, as they are operated at field levels much lower than the nominal one. This paper presents a feedback after three years of oper-ation, focuses on the RF issues, describing problems and required improvement on the low level, control and pow-er systems
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOPA15
About •	Received ※ 14 August 2022 — Revised ※ 17 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 02 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOJO03	Optimized Beam Optics Design of the MINERVA/MYRRHA Superconducting Proton Linac	337
	U. Dorda, L. De Keukeleere SCK•CEN, Mol, Belgium F. Bouly, E. Froidefond LPSC, Grenoble Cedex, France E. Bouquerel, E.K. Traykov IPHC, Strasbourg Cedex 2, France L. Perrot Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
	The MYRRHA design for an accelerator driven system (ADS) is based on a 600 MeV superconducting proton linac. The first stage towards its realization is called MINERVA and was approved in 2018 to be constructed by SCK•CEN in Belgium. This 100 MeV linac, will serve as technology demonstrator for the high MYRRHA reliability requirements as well as driver for two independent target stations, one for radio-isotope research and production of radio-isotopes for medical purposes, the other one for fusion materials research. This contribution gives an overview of the latest accelerator machine physics design with a focus on the optimized medium (17 MeV) and high energy (100 MeV) beam transfer lines.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOJO03
About •	Received ※ 16 August 2022 — Revised ※ 28 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 02 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPORI04	Cavity Failure Compensation Strategies in Superconducting Linacs	552
	A. Plaçais, F. Bouly LPSC, Grenoble Cedex, France
	RF cavities in linear accelerators are subject to failure, preventing the beam from reaching it’s nominal energy. This is particularly problematic for Accelerator Driven Systems (ADS), where the thermal fluctuations of the spallation target must be avoided and every fault shall be rapidly compensated for. In this study we present LightWin. This tool under development aims to create a database of the possible cavity failures and their associated compensation settings for a given accelerator. We apply it on the MYRRHA ADS, with a scenario including various faults distributed along the accelerator, and compare the settings found by LightWin to those found by the code TraceWin. We show that both tools find different compensation settings. We also outline the limitations of LightWin and explain the upcoming improvements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI04
About •	Received ※ 23 August 2022 — Revised ※ 20 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 11 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOPA13	Superconducting Cavity and RF Control Loop Model for the SPIRAL2 Linac	767
	F. Bouly LPSC, Grenoble Cedex, France M. Di Giacomo, J.F. Leyge, M. Tontayeva GANIL, Caen, France
	The SPIRAL2 superconducting linac has been successfully commissioned with protons in 2020. During the commissioning, a model of the cavity and its LLRF control loop has been developed. The model enables to have better understanding of the system and was used to guide the tuning of the PI(D) correctors for beam loading compensation. Here we review the development of such a tool, computed with MATLAB Simulink and using the frequency domain (Laplace transfer function) to model the cavity RF and mechanical behaviours (Lorentz detuning), as well as all elements that compose the RF control loop (digital LLRF, amplifier, transmission lines, etc.). The benchmarking of the model with measurement carried out with the proton beam is also discussed in this contribution.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOPA13
About •	Received ※ 24 August 2022 — Revised ※ 01 September 2022 — Accepted ※ 03 September 2022 — Issue date ※ 15 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Three Years of Operation of the SPIRAL2 SC LINAC- RF Feedback

98

M. Di Giacomo, M. Aburas, P.-E. Bernaudin, O. Delahaye, A. Dubosq, A. Ghribi, J.-M. Lagniel, J.F. Leyge, G. Normand, A.K. Orduz, F. Pillon, L. Valentin
GANIL, Caen, France
F. Bouly
LPSC, Grenoble Cedex, France
S. Sube
CEA-DRF-IRFU, France

The superconducting LINAC of SPIRAL2 at the GANIL facility has been in operation since October 2019. The accelerator uses 12 low beta and 14 high beta supercon-ducting quarter wave cavities, cooled at 4°K, working at 88 MHz. The cavities are operated at a nominal gradient of 6.5 MV/m and are independently powered by a LLRF and a solid-state amplifier, protected by a circulator. Pro-ton and deuteron beam currents can reach 5 mA and beam loading perturbation is particularly strong on the first cavities, as they are operated at field levels much lower than the nominal one. This paper presents a feedback after three years of oper-ation, focuses on the RF issues, describing problems and required improvement on the low level, control and pow-er systems

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-MOPOPA15

About •

Received ※ 14 August 2022 — Revised ※ 17 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 02 September 2022

Cite •

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

TUPOJO03

Optimized Beam Optics Design of the MINERVA/MYRRHA Superconducting Proton Linac

337

U. Dorda, L. De Keukeleere
SCK•CEN, Mol, Belgium
F. Bouly, E. Froidefond
LPSC, Grenoble Cedex, France
E. Bouquerel, E.K. Traykov
IPHC, Strasbourg Cedex 2, France
L. Perrot
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France

The MYRRHA design for an accelerator driven system (ADS) is based on a 600 MeV superconducting proton linac. The first stage towards its realization is called MINERVA and was approved in 2018 to be constructed by SCK•CEN in Belgium. This 100 MeV linac, will serve as technology demonstrator for the high MYRRHA reliability requirements as well as driver for two independent target stations, one for radio-isotope research and production of radio-isotopes for medical purposes, the other one for fusion materials research. This contribution gives an overview of the latest accelerator machine physics design with a focus on the optimized medium (17 MeV) and high energy (100 MeV) beam transfer lines.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPOJO03

About •

Received ※ 16 August 2022 — Revised ※ 28 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 02 September 2022

Cite •

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

TUPORI04

Cavity Failure Compensation Strategies in Superconducting Linacs

552

A. Plaçais, F. Bouly
LPSC, Grenoble Cedex, France

RF cavities in linear accelerators are subject to failure, preventing the beam from reaching it’s nominal energy. This is particularly problematic for Accelerator Driven Systems (ADS), where the thermal fluctuations of the spallation target must be avoided and every fault shall be rapidly compensated for. In this study we present LightWin. This tool under development aims to create a database of the possible cavity failures and their associated compensation settings for a given accelerator. We apply it on the MYRRHA ADS, with a scenario including various faults distributed along the accelerator, and compare the settings found by LightWin to those found by the code TraceWin. We show that both tools find different compensation settings. We also outline the limitations of LightWin and explain the upcoming improvements.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-TUPORI04

About •

Received ※ 23 August 2022 — Revised ※ 20 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 11 September 2022

Cite •

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

THPOPA13

Superconducting Cavity and RF Control Loop Model for the SPIRAL2 Linac

767

F. Bouly
LPSC, Grenoble Cedex, France
M. Di Giacomo, J.F. Leyge, M. Tontayeva
GANIL, Caen, France

The SPIRAL2 superconducting linac has been successfully commissioned with protons in 2020. During the commissioning, a model of the cavity and its LLRF control loop has been developed. The model enables to have better understanding of the system and was used to guide the tuning of the PI(D) correctors for beam loading compensation. Here we review the development of such a tool, computed with MATLAB Simulink and using the frequency domain (Laplace transfer function) to model the cavity RF and mechanical behaviours (Lorentz detuning), as well as all elements that compose the RF control loop (digital LLRF, amplifier, transmission lines, etc.). The benchmarking of the model with measurement carried out with the proton beam is also discussed in this contribution.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOPA13

About •

Received ※ 24 August 2022 — Revised ※ 01 September 2022 — Accepted ※ 03 September 2022 — Issue date ※ 15 September 2022

Cite •

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