ECRIS2024 - List of Authors (Thuillier, T.)

Paper	Title	Page
TUA3	The electrostatic deceleration of ions injected into an ECRIS CB plasma
	J. Angot, T. Thuillier LPSC, Grenoble Cedex, France A. Galatà INFN-LNL, Legnaro (PD), Italy O.A. Tarvainen STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom P. Chauveau GANIL, Caen, France
	The capture of the 1+ beam is a key parameter in the charge breeding process with an ECRIS-Charge Breeder as it greatly influences the 1+N+ conversion efficiency. The shape of the efficiency vs incident ion energy « Delta V » curve originally led to the theory of slowing down of the injected ions essentially by cumulative small-angle scatterings in collisions with the buffer gas ions. Recent experiments carried out with the PHOENIX charge breeder at LPSC tends to show that the electrostatic deceleration plays a greater role than historically considered. For this study, we varied the CB plasma potential by acting on the microwave power parameter and by measuring the optimum injection energy for sodium, rubidium and cesium ions. Both i) the correlation between the plasma potential and optimum injection energy parameters and ii) the independence of the optimum energy value as a function of the incident ion mass support the new model based on a slowing down essentially electrostatic.
	Slides TUA3 [2.588 MB]
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TUB2	Simulation of surface X-ray emission from the ASTERICS ECR ion source	81
	T. Thuillier, A. Cernuschi, B. Cheymol, M. Kasulja, E. Lagorio, C. Peaucelle, F. Vezzu LPSC, Grenoble Cedex, France M. Dubois, F. Lemagnen GANIL, Caen, France T. Cadoux, H. Felice, D. Simon CEA-IRFU, Gif-sur-Yvette, France
	A new electron cyclotron resonance ion source (ECRIS) named ASTERICS is under development for the NEWGAIN project, aiming at building a new injector for the SPIRAL2 accelerator at GANIL. A Monte Carlo code dedicated to the electron dynamics in ECRIS is used to investigate the local energy, position and velocity distribution of electrons impinging on the plasma chamber wall of ASTERICS. These quantities are presented for both the injection and extraction planes and the radial chamber wall. Results show that the electron energy distribution function is different on each of these three surfaces and that the electron velocity direction to the walls is deeply anisotropic. This data is next used as an input in a Fluka 3-dimensional model including the ASTERICS ECRIS mechanics, a simplified low energy beam line and the experimental cave in which the ion source will be installed. The x-ray flux characteristics around the source are presented. The shielding thickness and its location are studied to grant the safe passage of personnel around the ECRIS location in the accelerator building.
	Slides TUB2 [7.367 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUB2
About •	Received ※ 30 October 2024 — Revised ※ 31 October 2024 — Accepted ※ 29 January 2025 — Issued ※ 25 February 2025
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TUC2	Simulation of Bremsstrahlung emission in ECRIS and its dependence on the magnetic confinement
	A. Cernuschi, T. Thuillier LPSC, Grenoble Cedex, France
	Funding: This work is supported by Agence Nationale de la Recherche with the contract # 21-ESRE-0018 EQUIPEX+ NEWGAIN A Monte Carlo (MC) code dedicated to the electron dynamics in ECRIS was recently completed with a new functionality, allowing to simulate Bremsstrahlung photon emission from the volume interaction of electrons with charged particles inside the plasma. The simulation qualitatively reproduces the experimental anisotropy of the photon spectral temperature previously reported. The effects of variations in the magnetic field minimum Bmin and in the extraction peak on both the electron energy distribution function and the Bremsstrahlung emission are also investigated and reported. The simulation results confirm that only changes in Bmin influences the hot energy tail of the EEDF [1]. The MC high electron statistics allows studying with unprecedent details the location and mechanism responsible for the hot electrons generation in ECRIS, highlighting the crucial role of Bmin in this process. [1] J. Benitez, C. Lyneis, L. Phair, D. Todd, and D. Xie, IEEE Transactions on Plasma Science, vol. 45, p. 1746, 2017.
	Slides TUC2 [3.849 MB]
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MOP09	Status report on 60 GHz ECRIS activity	49
	T. Andre, A. Cernuschi, C. Peaucelle, E. Labussière, M. Migliore, J. Angot, M.A. Baylac, O. Zimmermann, P. Sole, P.-O. Dumont, T. Thuillier LPSC-IN2P3, Grenoble Cedex, France F. Debray Grenoble High Magnetic Field Laboratory, Grenoble, France
	SEISM (Sixty gigahErtz Ion Source using Megawatt magnets) is an electron cyclotron resonance ion source source operating at the frequency of 60 GHz using a gyrotron producing high intensity HF pulse (up to 1 ms/300 kW/2 Hz). The prototype is based on an axial cusp magnetic geometry using polyhelix coils (installed at the LNCMI facility in Grenoble) generating a closed ECR surface at 2.1 T. Since 2019 and the restart of the project, several experimental campaigns were carried out using oxygen support gas. Beam production was studied using the setting of the source aiming to reproduce the ion current densities of 1 A/cm² previously measured. Set up and recent experimental results, will be presented. Furthermore, in the frame of the PACIFICS project (funded by French National Research Agency under the Equipex Program), a new 60 GHz ion source will be built, where polyhelix will be replaced by superconducting coils and the source will be installed at LPSC for easier availability. A new extraction system will be built in order to transform the observed high current density into a target ion beam intensity of ~100 mA. This paper will present a preliminary study of the new extraction system, built upon the principles developed by Vybin [1]. The system’s design and optimization is carried out using COMSOL Multiphysics and IBSIMU simulation tools, ensuring precise modeling of electric field fields and ion trajectories. [1] S.S. Vybin et al., “Plasma Sources Sci. Technol.”, vol. 29, p. 11LT02, 2020
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP09
About •	Received ※ 15 September 2024 — Revised ※ 22 November 2024 — Accepted ※ 02 June 2025 — Issued ※ 22 June 2025
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Paper

Title

Page

TUA3

The electrostatic deceleration of ions injected into an ECRIS CB plasma

J. Angot, T. Thuillier
LPSC, Grenoble Cedex, France
A. Galatà
INFN-LNL, Legnaro (PD), Italy
O.A. Tarvainen
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
P. Chauveau
GANIL, Caen, France

The capture of the 1+ beam is a key parameter in the charge breeding process with an ECRIS-Charge Breeder as it greatly influences the 1+N+ conversion efficiency. The shape of the efficiency vs incident ion energy « Delta V » curve originally led to the theory of slowing down of the injected ions essentially by cumulative small-angle scatterings in collisions with the buffer gas ions. Recent experiments carried out with the PHOENIX charge breeder at LPSC tends to show that the electrostatic deceleration plays a greater role than historically considered. For this study, we varied the CB plasma potential by acting on the microwave power parameter and by measuring the optimum injection energy for sodium, rubidium and cesium ions. Both i) the correlation between the plasma potential and optimum injection energy parameters and ii) the independence of the optimum energy value as a function of the incident ion mass support the new model based on a slowing down essentially electrostatic.

Slides TUA3 [2.588 MB]

Cite •

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

TUB2

Simulation of surface X-ray emission from the ASTERICS ECR ion source

81

T. Thuillier, A. Cernuschi, B. Cheymol, M. Kasulja, E. Lagorio, C. Peaucelle, F. Vezzu
LPSC, Grenoble Cedex, France
M. Dubois, F. Lemagnen
GANIL, Caen, France
T. Cadoux, H. Felice, D. Simon
CEA-IRFU, Gif-sur-Yvette, France

A new electron cyclotron resonance ion source (ECRIS) named ASTERICS is under development for the NEWGAIN project, aiming at building a new injector for the SPIRAL2 accelerator at GANIL. A Monte Carlo code dedicated to the electron dynamics in ECRIS is used to investigate the local energy, position and velocity distribution of electrons impinging on the plasma chamber wall of ASTERICS. These quantities are presented for both the injection and extraction planes and the radial chamber wall. Results show that the electron energy distribution function is different on each of these three surfaces and that the electron velocity direction to the walls is deeply anisotropic. This data is next used as an input in a Fluka 3-dimensional model including the ASTERICS ECRIS mechanics, a simplified low energy beam line and the experimental cave in which the ion source will be installed. The x-ray flux characteristics around the source are presented. The shielding thickness and its location are studied to grant the safe passage of personnel around the ECRIS location in the accelerator building.

Slides TUB2 [7.367 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUB2

About •

Received ※ 30 October 2024 — Revised ※ 31 October 2024 — Accepted ※ 29 January 2025 — Issued ※ 25 February 2025

Cite •

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

TUC2

Simulation of Bremsstrahlung emission in ECRIS and its dependence on the magnetic confinement

A. Cernuschi, T. Thuillier
LPSC, Grenoble Cedex, France

Funding: This work is supported by Agence Nationale de la Recherche with the contract # 21-ESRE-0018 EQUIPEX+ NEWGAIN
A Monte Carlo (MC) code dedicated to the electron dynamics in ECRIS was recently completed with a new functionality, allowing to simulate Bremsstrahlung photon emission from the volume interaction of electrons with charged particles inside the plasma. The simulation qualitatively reproduces the experimental anisotropy of the photon spectral temperature previously reported. The effects of variations in the magnetic field minimum Bmin and in the extraction peak on both the electron energy distribution function and the Bremsstrahlung emission are also investigated and reported. The simulation results confirm that only changes in Bmin influences the hot energy tail of the EEDF [1]. The MC high electron statistics allows studying with unprecedent details the location and mechanism responsible for the hot electrons generation in ECRIS, highlighting the crucial role of Bmin in this process.
[1] J. Benitez, C. Lyneis, L. Phair, D. Todd, and D. Xie, IEEE Transactions on Plasma Science, vol. 45, p. 1746, 2017.

Slides TUC2 [3.849 MB]

Cite •

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

MOP09

Status report on 60 GHz ECRIS activity

49

T. Andre, A. Cernuschi, C. Peaucelle, E. Labussière, M. Migliore, J. Angot, M.A. Baylac, O. Zimmermann, P. Sole, P.-O. Dumont, T. Thuillier
LPSC-IN2P3, Grenoble Cedex, France
F. Debray
Grenoble High Magnetic Field Laboratory, Grenoble, France

SEISM (Sixty gigahErtz Ion Source using Megawatt magnets) is an electron cyclotron resonance ion source source operating at the frequency of 60 GHz using a gyrotron producing high intensity HF pulse (up to 1 ms/300 kW/2 Hz). The prototype is based on an axial cusp magnetic geometry using polyhelix coils (installed at the LNCMI facility in Grenoble) generating a closed ECR surface at 2.1 T. Since 2019 and the restart of the project, several experimental campaigns were carried out using oxygen support gas. Beam production was studied using the setting of the source aiming to reproduce the ion current densities of 1 A/cm² previously measured. Set up and recent experimental results, will be presented. Furthermore, in the frame of the PACIFICS project (funded by French National Research Agency under the Equipex Program), a new 60 GHz ion source will be built, where polyhelix will be replaced by superconducting coils and the source will be installed at LPSC for easier availability. A new extraction system will be built in order to transform the observed high current density into a target ion beam intensity of ~100 mA. This paper will present a preliminary study of the new extraction system, built upon the principles developed by Vybin [1]. The system’s design and optimization is carried out using COMSOL Multiphysics and IBSIMU simulation tools, ensuring precise modeling of electric field fields and ion trajectories.
[1] S.S. Vybin et al., “Plasma Sources Sci. Technol.”, vol. 29, p. 11LT02, 2020

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP09

About •

Received ※ 15 September 2024 — Revised ※ 22 November 2024 — Accepted ※ 02 June 2025 — Issued ※ 22 June 2025

Cite •

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