ECRIS2024 - List of Keywords (experiment)

Paper	Title	Other Keywords	Page
MOB1	GANIL ion sources: optimisation for operation	ion-source, ECR, plasma, cyclotron	5
	M. Dubois, B. Osmond, F. Lemagnen, L. Gouleuf, V. Metayer GANIL, Caen, France
	The GANIL (Grand Accélérateur National d’Ions Lourds) in Caen has been producing and accelerating stable and radioactive ion beams for nuclear physics, atomic physics, radiobiology and materials irradiation since 1982. On cyclotrons facility, two ion sources (ECR4 and ECR4M) are used to produce around 4,000 hours per year of gaseous and metallic beams. Recently, studies have been carried out to find ways of optimizing beam characteristics (stability, intensities). One of these involves improving the long-term stability of the beam, which is an important parameter for tuning the accelerator and for physics experiments. At the same time, this improved stability will also reduce the need of on-call interventions for ion source experts. Other studies and tests have been carried out to increase the intensity and/or stability of the metal beams by adapting the injection of the ion source on ECR4/4M. Depending on the configuration, the gain shall be up to a factor of 2 on the charge state required for acceleration, and stability has also been improved compared to previous one. Some details and results will be presented.
	Slides MOB1 [6.158 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOB1
About •	Received ※ 04 November 2024 — Revised ※ 22 November 2024 — Accepted ※ 20 January 2025 — Issued ※ 23 January 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOB2	ECRIS operation and developments at TRIUMF	ion-source, ECR, plasma, background	10
	F. Ames, J.A. Adegun, C.R.J. Charles, K. Jayamanna, O.K. Kester, B.E. Schultz TRIUMF, Vancouver, Canada
	Rare isotope beams are used at the ISAC facility at TRIUMF for studies mainly in nuclear and astrophysics, but also for applications ranging from material science to medicine. The isotopes are produced via the ISOL technique and ionized via a set of different ion sources depending on the application. In cases where highly charged ions are needed, charge state breeding is done with a 14.5 GHz PHOENIX ECR ion source from PANTECHNIK. The source has been operational for more than a decade providing a wide range of ions from Na to U at A/Q <7 for post-acceleration. A second ECR ion source, a SUPERNANOGAN also from PANTECHNIK is used to provide highly charged ions from stable isotopes either for set-up and calibration for the rare isotope beams or for nuclear reaction studies with stable ions. The presentation will give a summary of results and will describe the challenges and improvements to the original sources. For the charge state breeding this is mainly increasing the efficiency and the purity of the delivered beams. In the case of the SUPERNANOGAN special emphasis is put on operational aspects to cover a wide range of elements and easy switchover. The latest in this series of improvements is the implementation of two frequency plasma heating in both ion sources.
	Slides MOB2 [2.008 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOB2
About •	Received ※ 15 September 2024 — Revised ※ 25 November 2024 — Accepted ※ 29 January 2025 — Issued ※ 29 March 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOD2	Characterization of the ECR ion source LEGIS extraction system and its low energy beam transport line at Legnaro National Laboratories	LEBT, emittance, extraction, simulation	22
	G.R. Mascali INFN/LNL, Legnaro (PD), Italy L. Bellan, C.S. Gallo, D. Martini, P. Francescon, M. Comunian, O. Carletto, A. Galatà INFN-LNL, Legnaro (PD), Italy G.R. Mascali Sapienza University of Rome, Rome, Italy
	At INFN-Legnaro National Laboratories the heavy ions accelerator complex is fed with beams produced by a permanent magnet ECR source called LEGIS (LEGnaro ecrIS). Although suitable intensities and charge states to fulfil the requests of the users are normally guaranteed, the first part of the Low Energy Beam Transport line (LEBT) downstream of the ion source suffers from non-negligible losses and a lack of scalability when switching between ions with different mass-to-charge ratios, thus leading to a machine preparation time longer than would be desirable. These criticalities called for a deep characterization of the beam coming out from the ion source, especially in the case of high charge states heavy ions production, normally showing the lowest intensities. This contribution describes the numerical studies performed on the extraction system of the LEGIS source and its LEBT. The physics case used is a ²⁰⁸Pb³¹⁺ beam produced for a nuclear physics experiment in fall 2022. As will be shown, the results shed light on the reasons for the bad reproducibility and transmission, mostly due to aberrations induced on the extracted beam by the first optical elements.
	Slides MOD2 [7.465 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOD2
About •	Received ※ 04 October 2024 — Revised ※ 16 October 2024 — Accepted ※ 29 January 2025 — Issued ※ 15 June 2025
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MOP09	Status report on 60 GHz ECRIS activity	ion-source, LEBT, ECR, extraction	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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MOP10	Light ions from the GTS-LHC ion source for future physics at CERN	operation, emittance, rfq, extraction	53
	D. Küchler, B.S. Bhaskar, G. Bellodi, M. Slupecki, R. Scrivens CERN, Geneva, Switzerland
	Starting from 2028, physics programmes using ions at CERN have requested lighter ions than the lead usually produced. The Working Group on Future Ions in the CERN Accelerator Complex has been mandated to assess the feasibility of the production and operation of these new ion species. The ion beam production from two of the chosen elements, krypton and magnesium, was studied in the GTS-LHC ion source, and the preliminary results of beam intensity, stability and emittance will be presented, as well as proposed modifications to improve performance.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP10
About •	Received ※ 13 September 2024 — Revised ※ 17 September 2024 — Accepted ※ 29 January 2025 — Issued ※ 05 February 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP15	Study of noble gas memory effect of ECR3 at ATLAS	ECR, ion-source, detector, ECRIS	64
	R.H. Scott, J.T. McLain, R.C. Vondrasek ANL, Lemont, Illinois, USA M. Paul, S. Bhattacharya The Hebrew University of Jerusalem, Jerusalem, Israel
	Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. Over the past three decades a portion of the accelerated beam time at the Argonne Tandem Linac Accelerator System (ATLAS) has been reserved for ultra-sensitive detection of argon radioisotopes. A unique noble-gas accelerator mass spectrometry (NOGAMS) technique [1] at ATLAS combines electron cyclotron resonance ion source (ECRIS) positive ion production, acceleration up to ~6 MeV/u and detection methods for separating isobars and other m/q contaminants. The ECR3 ion source was chosen for such experiments due to the limited scope of material introduced into the plasma chamber, inferring a lower background production compared to ECR2. A recent ³⁹⸴⁴²Ar NOGAMS experiment has highlighted a need to understand the beam production of material that is no longer being actively introduced into the ECRIS, known as memory effect. A quantitative study of source memory was performed to determine the decay characteristics of argon in the ECR3 ion source. Results of this study as well as details of setup and operation of ECR3 for NOGAMS experiments are presented. [1] M. Paul et al., Nucl. Instr. and Methods in Phys. Res., Sect. B, vol. 456, p. 222, 2019. doi:10.1016/j.nimb.2019.04.003
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP15
About •	Received ※ 13 September 2024 — Revised ※ 20 September 2024 — Accepted ※ 29 May 2025 — Issued ※ 07 June 2025
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TUP09	Characterization of an proton ECR ion source for low beam current	ion-source, plasma, luminosity, ECR	112
	P. Usabiaga, I. Arredondo, J. Feuchtwanger University of the Basque Country (UPV/EHU), Leioa, Spain I. Ariz, J.M. Seara Eizaguirre Fundación TEKNIKER, Ebar (Gipuzkoa), Spain J. Feuchtwanger Ikerbasque, Bilbao, Spain J. Portilla, J. Vivas, V. Etxebarria University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
	Funding: Basque Government, Department of Industry, Elkartek KK-2022/00026 + Basque Government, Department of Education, IT1533-22 In this paper we analyze the behavior of a low beam current proton ECR ion source for linac. During the operation of the source, as a function of the operating parameters we have observed a complex behavior. The state of the plasma is highly dependent on the input parameters, and in some cases even bi-stable conditions can be achieved showing abrupt changes in the state. To try to understand this behavior we carried out a series of experiments varying the input parameters both sequentially and randomly to avoid following the same path every time. Thanks to these experiments we have been able to observe the change in the luminosity of the plasma, which is an indirect measure of the degree of ionization in the plasma, along with the changes in reflected and transmitted RF power delivered to the source. We also characterized the relation between the outside temperature of the ion source chamber walls and the plasma. In addition to this we have analyzed the resulting extracted ion beam using a pepperpot and a faraday cup. We have observed that our beam doesn’t have one dominant species and has three species that are found in comparable quantities.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUP09
About •	Received ※ 31 August 2024 — Revised ※ 13 September 2024 — Accepted ※ 19 September 2024 — Issued ※ 29 December 2024
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TUP10	Optical diagnostic studies to analyse electron cyclotron resonance plasma produced in the GTS-LHC ion source	ion-source, ECR, plasma, dipole	116
	B.S. Bhaskar, D. Küchler CERN, Geneva, Switzerland T. Kövener Private Address, ,
	The GTS-LHC electron cyclotron resonance (ECR) ion source is an integral part of the chain of accelerators at CERN. It produces the heavy ion beams which are accelerated using a series of accelerators from LINAC up to the LHC. The ion beams are extracted from an ECR plasma generated at the GTS-LHC ion source, however, there has not yet been a non-invasive diagnostic device to study the plasma. This research focuses on the implementation of an optical diagnostics and studies the optical emission spectra (OES) as a monitor of the performance of the ion source. Furthermore, we explore the correlation between spectral properties and changing source parameters, offering insights into the behaviour of the ion source, which in turn helps in fine-tuning of the source. Specifically, the study concentrates on long-term OES analysis spanning several weeks, focusing on the production of magnesium and lead ions using the GTS-LHC ion source.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUP10
About •	Received ※ 11 September 2024 — Revised ※ 19 September 2024 — Accepted ※ 09 October 2024 — Issued ※ 26 March 2025
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TUP14	3D simulations of the CAPRICE ECRIS extraction system	simulation, ECR, plasma, extraction	131
	M.A. Händler IAP, Frankfurt am Main, Germany A. Andreev, F. Maimone, G. Franchetti, J. Mäder, M. Galonska, R. Lang, R. Hollinger GSI, Darmstadt, Germany
	The simulation of the ion extraction from the Electron Cyclotron Resonance Ion Sources (ECRISs) is necessary for the optimization and development of the performance of ion sources. Due to the magnetic field configuration of the ECRISs the calculations need to be performed in 3D. Therefore simulation programs based i.e. on C⁺⁺ libraries like IBSimu were developed. In this work a physical model was implemented in IBSimu generating detailed 3D simulations of ion extraction from a CAPRICE-type ECRIS. Simulations of multi-species Argon ion beam including Helium contribution as support gas extracted from CAPRICE are carried out. The study includes the effect of different space charge compensation degrees. Furthermore, ion beams extracted with different plasma electrode apertures were analyzed in terms of ion beam current, beam profile, beam size, divergence angle, and beam quality. In addition the simulation results were compared to experimental findings, i.e. ion beam intensities and beam profiles measured with viewing screens.
	Poster TUP14 [5.264 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUP14
About •	Received ※ 20 December 2024 — Revised ※ 27 January 2025 — Accepted ※ 30 January 2025 — Issued ※ 17 April 2025
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WEA3	A plasma based, charge state stripper for heavy ion accelerators	plasma, electron, heavy-ion, target	144
	G.O. Rodrigues IUAC, New Delhi, India
	The ionization of ions to a higher charge state is of central importance for the development of new Accelerator Facilities like FAIR [1], and the resulting cost savings. Currently, mainly gas and foil strippers are used for increasing the charge state even after using a high performance ECR ion source in a typical Accelerator chain. Even when the foil or/and gas stripper efficiency or lifetime has proved to be less than optimal, as these alternatives either require great effort or are practically not suitable for smooth operation in the long term. Free electrons in highly ionized plasmas [2,3] can be effectively used for improving the charge state of heavy ions as the rates of radiative recombination of free electrons are much smaller than those of electron capture on bound electrons, which leads to a substantial increase of the effective charge in a plasma compared to a cold-gas target of the same element. Theta and Z pinch plasmas are possible options which have been explored and experimentally studied at IAP, Frankfurt, Germany [4]. Typical electron line densities required to be achieved are in the range of 10¹⁶ to 10¹⁹ cm⁻³ and electron temperatures of the order of few tens of eV are found to be very favourable as per modelling with the FLYCHK code [5], but also extremely challenging. Such a plasma device, the challenges to be overcome, together with their design details will be presented. [1] https://fair-center.eu/ [2] E. Nardi and Z. Zinamon, Phys. Rev. Lett., vol. 49, p. 1251, 1982. [3] T. Peter and J. Meyer-ter-Vehn, “Energy loss of heavy ions in dense plasma. II. Nonequilibrium charge states and stopping powers”, Phys. Rev. A, vol. 43, pp. 2015–2030, 1991. doi:10.1103/PhysRevA.43.2015 [4] C. Teske, J. Jacoby, F. Senzel, W. Schweizer, Phys. Plasmas, vol. 17, p. 043501, 2010. [5] FLYCHK code: www-amdis.iaea.org
	Slides WEA3 [5.462 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-WEA3
About •	Received ※ 28 March 2025 — Revised ※ 26 May 2025 — Accepted ※ 29 June 2025 — Issued ※ 30 June 2025
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WEB1	Mixed carbon and helium ion beams for simultaneous heavy ion radiotherapy and radiography: an ion source perspective	ion-source, plasma, instrumentation, ECR	148
	M. Galonska, A. Andreev, C. Graeff, F. Maimone, J. Mäder, L. Volz, R. Lang, R. Hollinger GSI, Darmstadt, Germany C. Graeff TU Darmstadt, Darmstadt, Germany
	Within the framework of research on simultaneous heavy ion radiotherapy and radiography, a mixed carbon/helium ion beam with a variable He percentage has been successfully established and investigated at GSI for the first time in order to study this new mode of image guidance for carbon ion beam therapy. The mixed C/He ion beam was provided by the 14.5 GHz CAPRICE ECR ion source for the subsequent linac-synchrotron accelerator systems at GSI. Prior to that experiment, different ion combinations (¹²C³⁺/⁴He⁺ or ¹²C⁴⁺/³He⁺) out of CH₄ or CO₂ have been investigated at the ECR test bench in terms of ion beam currents, stability, and C-to-He-fraction quantified by optical spectral lines and mass spectra. From an ion source perspective, it turned out that each of the different combinations comply with all the requirements of the experiments which successfully took place utilizing a ¹²C³⁺/⁴He⁺- ion beam with an energy of 225 MeV/u. Finally, both ions were simultaneously accelerated and extracted and characterised in the biophysics cave. This paper briefly outlines some of the measurements obtained at the test bench and during the beam time from an ion source perspective.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-WEB1
About •	Received ※ 15 January 2025 — Revised ※ 24 January 2025 — Accepted ※ 26 February 2025 — Issued ※ 22 May 2025
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Paper

Title

Other Keywords

Page

MOB1

GANIL ion sources: optimisation for operation

ion-source, ECR, plasma, cyclotron

5

M. Dubois, B. Osmond, F. Lemagnen, L. Gouleuf, V. Metayer
GANIL, Caen, France

The GANIL (Grand Accélérateur National d’Ions Lourds) in Caen has been producing and accelerating stable and radioactive ion beams for nuclear physics, atomic physics, radiobiology and materials irradiation since 1982. On cyclotrons facility, two ion sources (ECR4 and ECR4M) are used to produce around 4,000 hours per year of gaseous and metallic beams. Recently, studies have been carried out to find ways of optimizing beam characteristics (stability, intensities). One of these involves improving the long-term stability of the beam, which is an important parameter for tuning the accelerator and for physics experiments. At the same time, this improved stability will also reduce the need of on-call interventions for ion source experts. Other studies and tests have been carried out to increase the intensity and/or stability of the metal beams by adapting the injection of the ion source on ECR4/4M. Depending on the configuration, the gain shall be up to a factor of 2 on the charge state required for acceleration, and stability has also been improved compared to previous one. Some details and results will be presented.

Slides MOB1 [6.158 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOB1

About •

Received ※ 04 November 2024 — Revised ※ 22 November 2024 — Accepted ※ 20 January 2025 — Issued ※ 23 January 2025

Cite •

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

MOB2

ECRIS operation and developments at TRIUMF

ion-source, ECR, plasma, background

10

F. Ames, J.A. Adegun, C.R.J. Charles, K. Jayamanna, O.K. Kester, B.E. Schultz
TRIUMF, Vancouver, Canada

Rare isotope beams are used at the ISAC facility at TRIUMF for studies mainly in nuclear and astrophysics, but also for applications ranging from material science to medicine. The isotopes are produced via the ISOL technique and ionized via a set of different ion sources depending on the application. In cases where highly charged ions are needed, charge state breeding is done with a 14.5 GHz PHOENIX ECR ion source from PANTECHNIK. The source has been operational for more than a decade providing a wide range of ions from Na to U at A/Q <7 for post-acceleration. A second ECR ion source, a SUPERNANOGAN also from PANTECHNIK is used to provide highly charged ions from stable isotopes either for set-up and calibration for the rare isotope beams or for nuclear reaction studies with stable ions. The presentation will give a summary of results and will describe the challenges and improvements to the original sources. For the charge state breeding this is mainly increasing the efficiency and the purity of the delivered beams. In the case of the SUPERNANOGAN special emphasis is put on operational aspects to cover a wide range of elements and easy switchover. The latest in this series of improvements is the implementation of two frequency plasma heating in both ion sources.

Slides MOB2 [2.008 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOB2

About •

Received ※ 15 September 2024 — Revised ※ 25 November 2024 — Accepted ※ 29 January 2025 — Issued ※ 29 March 2025

Cite •

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

MOD2

Characterization of the ECR ion source LEGIS extraction system and its low energy beam transport line at Legnaro National Laboratories

LEBT, emittance, extraction, simulation

22

G.R. Mascali
INFN/LNL, Legnaro (PD), Italy
L. Bellan, C.S. Gallo, D. Martini, P. Francescon, M. Comunian, O. Carletto, A. Galatà
INFN-LNL, Legnaro (PD), Italy
G.R. Mascali
Sapienza University of Rome, Rome, Italy

At INFN-Legnaro National Laboratories the heavy ions accelerator complex is fed with beams produced by a permanent magnet ECR source called LEGIS (LEGnaro ecrIS). Although suitable intensities and charge states to fulfil the requests of the users are normally guaranteed, the first part of the Low Energy Beam Transport line (LEBT) downstream of the ion source suffers from non-negligible losses and a lack of scalability when switching between ions with different mass-to-charge ratios, thus leading to a machine preparation time longer than would be desirable. These criticalities called for a deep characterization of the beam coming out from the ion source, especially in the case of high charge states heavy ions production, normally showing the lowest intensities. This contribution describes the numerical studies performed on the extraction system of the LEGIS source and its LEBT. The physics case used is a ²⁰⁸Pb³¹⁺ beam produced for a nuclear physics experiment in fall 2022. As will be shown, the results shed light on the reasons for the bad reproducibility and transmission, mostly due to aberrations induced on the extracted beam by the first optical elements.

Slides MOD2 [7.465 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOD2

About •

Received ※ 04 October 2024 — Revised ※ 16 October 2024 — Accepted ※ 29 January 2025 — Issued ※ 15 June 2025

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MOP09

Status report on 60 GHz ECRIS activity

ion-source, LEBT, ECR, extraction

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

MOP10

Light ions from the GTS-LHC ion source for future physics at CERN

operation, emittance, rfq, extraction

53

D. Küchler, B.S. Bhaskar, G. Bellodi, M. Slupecki, R. Scrivens
CERN, Geneva, Switzerland

Starting from 2028, physics programmes using ions at CERN have requested lighter ions than the lead usually produced. The Working Group on Future Ions in the CERN Accelerator Complex has been mandated to assess the feasibility of the production and operation of these new ion species. The ion beam production from two of the chosen elements, krypton and magnesium, was studied in the GTS-LHC ion source, and the preliminary results of beam intensity, stability and emittance will be presented, as well as proposed modifications to improve performance.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP10

About •

Received ※ 13 September 2024 — Revised ※ 17 September 2024 — Accepted ※ 29 January 2025 — Issued ※ 05 February 2025

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

MOP15

Study of noble gas memory effect of ECR3 at ATLAS

ECR, ion-source, detector, ECRIS

64

R.H. Scott, J.T. McLain, R.C. Vondrasek
ANL, Lemont, Illinois, USA
M. Paul, S. Bhattacharya
The Hebrew University of Jerusalem, Jerusalem, Israel

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
Over the past three decades a portion of the accelerated beam time at the Argonne Tandem Linac Accelerator System (ATLAS) has been reserved for ultra-sensitive detection of argon radioisotopes. A unique noble-gas accelerator mass spectrometry (NOGAMS) technique [1] at ATLAS combines electron cyclotron resonance ion source (ECRIS) positive ion production, acceleration up to ~6 MeV/u and detection methods for separating isobars and other m/q contaminants. The ECR3 ion source was chosen for such experiments due to the limited scope of material introduced into the plasma chamber, inferring a lower background production compared to ECR2. A recent ³⁹⸴⁴²Ar NOGAMS experiment has highlighted a need to understand the beam production of material that is no longer being actively introduced into the ECRIS, known as memory effect. A quantitative study of source memory was performed to determine the decay characteristics of argon in the ECR3 ion source. Results of this study as well as details of setup and operation of ECR3 for NOGAMS experiments are presented.
[1] M. Paul et al., Nucl. Instr. and Methods in Phys. Res., Sect. B, vol. 456, p. 222, 2019. doi:10.1016/j.nimb.2019.04.003

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP15

About •

Received ※ 13 September 2024 — Revised ※ 20 September 2024 — Accepted ※ 29 May 2025 — Issued ※ 07 June 2025

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TUP09

Characterization of an proton ECR ion source for low beam current

ion-source, plasma, luminosity, ECR

112

P. Usabiaga, I. Arredondo, J. Feuchtwanger
University of the Basque Country (UPV/EHU), Leioa, Spain
I. Ariz, J.M. Seara Eizaguirre
Fundación TEKNIKER, Ebar (Gipuzkoa), Spain
J. Feuchtwanger
Ikerbasque, Bilbao, Spain
J. Portilla, J. Vivas, V. Etxebarria
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain

Funding: Basque Government, Department of Industry, Elkartek KK-2022/00026 + Basque Government, Department of Education, IT1533-22
In this paper we analyze the behavior of a low beam current proton ECR ion source for linac. During the operation of the source, as a function of the operating parameters we have observed a complex behavior. The state of the plasma is highly dependent on the input parameters, and in some cases even bi-stable conditions can be achieved showing abrupt changes in the state. To try to understand this behavior we carried out a series of experiments varying the input parameters both sequentially and randomly to avoid following the same path every time. Thanks to these experiments we have been able to observe the change in the luminosity of the plasma, which is an indirect measure of the degree of ionization in the plasma, along with the changes in reflected and transmitted RF power delivered to the source. We also characterized the relation between the outside temperature of the ion source chamber walls and the plasma. In addition to this we have analyzed the resulting extracted ion beam using a pepperpot and a faraday cup. We have observed that our beam doesn’t have one dominant species and has three species that are found in comparable quantities.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUP09

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Received ※ 31 August 2024 — Revised ※ 13 September 2024 — Accepted ※ 19 September 2024 — Issued ※ 29 December 2024

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TUP10

Optical diagnostic studies to analyse electron cyclotron resonance plasma produced in the GTS-LHC ion source

ion-source, ECR, plasma, dipole

116

B.S. Bhaskar, D. Küchler
CERN, Geneva, Switzerland
T. Kövener
Private Address, ,

The GTS-LHC electron cyclotron resonance (ECR) ion source is an integral part of the chain of accelerators at CERN. It produces the heavy ion beams which are accelerated using a series of accelerators from LINAC up to the LHC. The ion beams are extracted from an ECR plasma generated at the GTS-LHC ion source, however, there has not yet been a non-invasive diagnostic device to study the plasma. This research focuses on the implementation of an optical diagnostics and studies the optical emission spectra (OES) as a monitor of the performance of the ion source. Furthermore, we explore the correlation between spectral properties and changing source parameters, offering insights into the behaviour of the ion source, which in turn helps in fine-tuning of the source. Specifically, the study concentrates on long-term OES analysis spanning several weeks, focusing on the production of magnesium and lead ions using the GTS-LHC ion source.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUP10

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Received ※ 11 September 2024 — Revised ※ 19 September 2024 — Accepted ※ 09 October 2024 — Issued ※ 26 March 2025

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TUP14

3D simulations of the CAPRICE ECRIS extraction system

simulation, ECR, plasma, extraction

131

M.A. Händler
IAP, Frankfurt am Main, Germany
A. Andreev, F. Maimone, G. Franchetti, J. Mäder, M. Galonska, R. Lang, R. Hollinger
GSI, Darmstadt, Germany

The simulation of the ion extraction from the Electron Cyclotron Resonance Ion Sources (ECRISs) is necessary for the optimization and development of the performance of ion sources. Due to the magnetic field configuration of the ECRISs the calculations need to be performed in 3D. Therefore simulation programs based i.e. on C⁺⁺ libraries like IBSimu were developed. In this work a physical model was implemented in IBSimu generating detailed 3D simulations of ion extraction from a CAPRICE-type ECRIS. Simulations of multi-species Argon ion beam including Helium contribution as support gas extracted from CAPRICE are carried out. The study includes the effect of different space charge compensation degrees. Furthermore, ion beams extracted with different plasma electrode apertures were analyzed in terms of ion beam current, beam profile, beam size, divergence angle, and beam quality. In addition the simulation results were compared to experimental findings, i.e. ion beam intensities and beam profiles measured with viewing screens.

Poster TUP14 [5.264 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUP14

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Received ※ 20 December 2024 — Revised ※ 27 January 2025 — Accepted ※ 30 January 2025 — Issued ※ 17 April 2025

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WEA3

A plasma based, charge state stripper for heavy ion accelerators

plasma, electron, heavy-ion, target

144

G.O. Rodrigues
IUAC, New Delhi, India

The ionization of ions to a higher charge state is of central importance for the development of new Accelerator Facilities like FAIR [1], and the resulting cost savings. Currently, mainly gas and foil strippers are used for increasing the charge state even after using a high performance ECR ion source in a typical Accelerator chain. Even when the foil or/and gas stripper efficiency or lifetime has proved to be less than optimal, as these alternatives either require great effort or are practically not suitable for smooth operation in the long term. Free electrons in highly ionized plasmas [2,3] can be effectively used for improving the charge state of heavy ions as the rates of radiative recombination of free electrons are much smaller than those of electron capture on bound electrons, which leads to a substantial increase of the effective charge in a plasma compared to a cold-gas target of the same element. Theta and Z pinch plasmas are possible options which have been explored and experimentally studied at IAP, Frankfurt, Germany [4]. Typical electron line densities required to be achieved are in the range of 10¹⁶ to 10¹⁹ cm⁻³ and electron temperatures of the order of few tens of eV are found to be very favourable as per modelling with the FLYCHK code [5], but also extremely challenging. Such a plasma device, the challenges to be overcome, together with their design details will be presented.
[1] https://fair-center.eu/
[2] E. Nardi and Z. Zinamon, Phys. Rev. Lett., vol. 49, p. 1251, 1982.
[3] T. Peter and J. Meyer-ter-Vehn, “Energy loss of heavy ions in dense plasma. II. Nonequilibrium charge states and stopping powers”, Phys. Rev. A, vol. 43, pp. 2015–2030, 1991. doi:10.1103/PhysRevA.43.2015
[4] C. Teske, J. Jacoby, F. Senzel, W. Schweizer, Phys. Plasmas, vol. 17, p. 043501, 2010.
[5] FLYCHK code: www-amdis.iaea.org

Slides WEA3 [5.462 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-WEA3

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Received ※ 28 March 2025 — Revised ※ 26 May 2025 — Accepted ※ 29 June 2025 — Issued ※ 30 June 2025

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WEB1

Mixed carbon and helium ion beams for simultaneous heavy ion radiotherapy and radiography: an ion source perspective

ion-source, plasma, instrumentation, ECR

148

M. Galonska, A. Andreev, C. Graeff, F. Maimone, J. Mäder, L. Volz, R. Lang, R. Hollinger
GSI, Darmstadt, Germany
C. Graeff
TU Darmstadt, Darmstadt, Germany

Within the framework of research on simultaneous heavy ion radiotherapy and radiography, a mixed carbon/helium ion beam with a variable He percentage has been successfully established and investigated at GSI for the first time in order to study this new mode of image guidance for carbon ion beam therapy. The mixed C/He ion beam was provided by the 14.5 GHz CAPRICE ECR ion source for the subsequent linac-synchrotron accelerator systems at GSI. Prior to that experiment, different ion combinations (¹²C³⁺/⁴He⁺ or ¹²C⁴⁺/³He⁺) out of CH₄ or CO₂ have been investigated at the ECR test bench in terms of ion beam currents, stability, and C-to-He-fraction quantified by optical spectral lines and mass spectra. From an ion source perspective, it turned out that each of the different combinations comply with all the requirements of the experiments which successfully took place utilizing a ¹²C³⁺/⁴He⁺- ion beam with an energy of 225 MeV/u. Finally, both ions were simultaneously accelerated and extracted and characterised in the biophysics cave. This paper briefly outlines some of the measurements obtained at the test bench and during the beam time from an ion source perspective.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-WEB1

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Received ※ 15 January 2025 — Revised ※ 24 January 2025 — Accepted ※ 26 February 2025 — Issued ※ 22 May 2025

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