ECRIS2024 - List of Keywords (plasma)

Paper	Title	Other Keywords	Page
MOB1	GANIL ion sources: optimisation for operation	ion-source, ECR, experiment, 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, experiment, ECR, 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)

MOC1	Recent achievements in the production of metallic ion beams with the CAPRICE ECRIS at GSI	operation, ECR, ECRIS, extraction	14
	A. Andreev, F. Maimone, J. Mäder, M. Galonska, R. Lang, R. Hollinger GSI, Darmstadt, Germany
	The GSI CAPRICE Electron Cyclotron Resonance Ion Source (ECRIS) provides highly-charged ion beams for various experiments at GSI, enabling the delivery of continuous wave (CW) metallic ion beams with low material consumption, which is crucial for producing high charge state ion beams from rare or extremely rare isotopes such as ⁴⁸Ca. These metallic beams are produced utilizing the thermal evaporation technique by resistively heated ovens. Due to the research groups’ demand for higher beam intensities, increased ion currents of higher charge states are now necessary from the CAPRICE ECRIS. A test campaign was conducted to establish and improve the production of high charge states of enriched ⁵⁴Cr and ⁵⁵Mn ion beams. During the tests, plasma images were captured using a CCD camera to support the operation and enable real-time monitoring of the material consumption. Additionally, a hot screen was used to protect the ceramic insulators in the extraction system from metal deposition, thereby improving the operational stability of the ECRIS. The application of an optical emission spectroscopy to monitor the stability of metallic ion beams during the operation with the resistively heated ovens was also investigated. This contribution presents the operational experience, the intensities and stability achieved for the aforementioned elements. In addition, an update on a recent improvement involving a specialized oven preparation stand for better conditioning of the ovens is given.
	Slides MOC1 [3.835 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOC1
About •	Received ※ 13 December 2024 — Revised ※ 21 January 2025 — Accepted ※ 29 January 2025 — Issued ※ 14 May 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOC2	A novel inductive oven design for the production of high current, metal ion beams	cyclotron, ion-source, target, electron	19
	D.S. Todd, J.Y. Benitez LBNL, Berkeley, CA, USA
	Essential to the proposed search for element 120 at LBNL’s 88-Inch Cyclotron is the continual delivery of over a particle microamp of ⁵⁰Ti¹²⁺ for weeks-long campaigns spanning many months. The fully-superconducting ECR ion source VENUS will be the injector source for these runs, and we have developed a new inductive oven design that can survive VENUS’ high magnetic fields while injecting metallic gas into the plasma with high efficiency. The new oven employs a vertical susceptor to permit use with metals that melt before outgassing sufficiently, while also allowing a rotation of the oven’s material exit toward the plasma center for better conversion efficiency to the produced beam. The performance of VENUS with this oven has been outstanding: as reported here, 282 MeV ⁵⁰Ti¹²⁺ beams with stable currents between 1.0 and 1.5 pμA have been delivered for superheavy element searches over multiple ten-day runs.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOC2
About •	Received ※ 04 October 2024 — Revised ※ 10 October 2024 — Accepted ※ 29 January 2025 — Issued ※ 22 June 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOD1	Development of deuterium-deuterium compact neutron source	target, neutron, vacuum, electron	23
	A. Pérez, I. Arredondo, J. Portilla, V. Etxebarria University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain A. Roldán, J. Praena UGR, Granada, Spain J. Feuchtwanger Ikerbasque, Bilbao, Spain
	In the present work, we will present the status of the deuterium-deuterium (D-D) neutron source that is being developed in collaboration between the University of Granada and the University of the Basque Country (Spain). Our neutron source consists of an ECR ion source which accelerates a deuteron beam towards a deuterated target. The ionization to achieve the deuterium plasma is achieved by radiating the cylindrical ERC plasma chamber with a magnetron 2.45 GHz signal and an 875 G magnetic field generated by 6 NdFeB magnets located around the plasma chamber. Moreover, a cylindrical alumina RF window is used to keep the vacuum status from the ambient pressure condition inside the WR340 and helping the plasma to ignite. Once the plasma is generated, the deuterons are extracted from the plasma chamber using a Pierce electrode geometry and three other electrostatic lenses, fixed to different negative potentials. The beam is accelerated towards copper target disk with a deuterated titanium mesh fixed to -100 kV which generates the desired neutron radiation. There are several applications of D-D neutron sources across scientific and industrial domains. In case of University of Granada and its deep relation with IFMIF-DONES neutron source, it is worthy to mention that we plan to carry out experiments for determining the cross-sections of relevant isotopes in the studies of IFMIF-DONES to a better simulation of the behaviour of such material under high neutron flux irradiation.
	Slides MOD1 [9.890 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOD1
About •	Received ※ 14 September 2024 — Revised ※ 17 September 2024 — Accepted ※ 29 January 2025 — Issued ※ 21 June 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP01	Characterization of the 2.45 GHz DREEBIT ECRIS via optical spectroscopy	electron, ECR, ECRIS, ion-source	31
	M. Molodtsova, A. Philipp, E. Ritter DREEBIT, Großröhrsdorf, Germany
	ECR ion sources are widely used to provide ions for various experimental setups. DREEBIT GmbH aims to industrialize this type of ion source technology for efficient and reliable use in, e. g., hadron cancer therapy as well as ion implantation of semiconductors. Our goal is to build table-top sized ion sources which can easily be handled as part of a larger machine such as a particle accelerator or target irradiation facility, thereby fulfilling high requirements on beam current, quality, stability as well as reproducibility in serial production. To achieve this, we have already optimized the microwave injection system and magnetic plasma confinement by introducing a simple method to allow for injection of circularly polarized waves and adjusted the magnetic field distribution which led to an 80 % increase of beam current. In the present work, we show how optical emission spectroscopy was used to gain deeper information about the plasma of this specific type of ion source, independent from its ion extraction system. The plasma characterization includes studies of the electron energy distribution and the density of atomic and molecular hydrogen showing that the previous design changes of introducing circularly polarized microwaves and optimizing the magnetic field distribution have led to a well-optimized ECR ion source concerning plasma heating and proton production inside the plasma, indicating how the source performance can be enhanced in further steps.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP01
About •	Received ※ 02 October 2024 — Revised ※ 09 October 2024 — Accepted ※ 29 January 2025 — Issued ※ 07 April 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP03	ALISES II source is still alive at CEA Saclay	ion-source, proton, rfq, emittance	35
	O. Delferrière, A. Dubois, D. Uriot, J. Schwindling, O. Tuske, Y. Gauthier, Y. Sauce CEA-IRFU, Gif-sur-Yvette, France F. Mezei Mirrotron Ltd., Budapest, Hungary
	Developments of ECR intense light ion sources is an important research axis of the Laboratory of Study and Development of Accelerator at CEA-Saclay. Starting from the SILHI proton source in the 90’s to inject the IPHI accelerator, several SILHI-type sources have been realized and installed for high intensity proton or deuteron accelerators for international projects like IFMIF, FAIR or SPIRAL2. From 2011, we started new R&D program on high intensity ECR compact ion sources with the ALISES source family. The results obtained with the first ALISES source prototype gave us the main goals for the design of ALISES II source that runs several months on our 50 kV test bench BETSI and was dismounted at the end of 2016 to upgrade the test bench to 100 kV. But this source was never reinstalled and has been replaced by the ALISES III sources that runs on BETSI up to now. Recently, ALISES II ion source and its equipment is reassembled to be restarted on BETSI for beam characterization before sending it to MIRROTRON factory in Hungary as injector of proton for neutron beam facility. This paper describes the setup on BETSI and proton beam characteristics obtained by emittance measurements, spatial species proportion analysis with Wien filter and current optimization. Installation at MIRROTRON factory is also reported.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP03
About •	Received ※ 13 September 2024 — Revised ※ 16 September 2024 — Accepted ※ 29 January 2025 — Issued ※ 17 February 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP04	ALISES v3 ion source in various configuration along the year	ion-source, extraction, proton, electron	39
	O. Tuske, A. Dubois, O. Delferrière, Y. Gauthier, Y. Sauce CEA-IRFU, Gif-sur-Yvette, France
	ALISESv3 is a very compact light ion source that has been developed at CEA Saclay in 2018. The easy maintenance procedure of this source allowed us to test many different configurations. On the BETSI test bench equipped with an single Alisson Scanner and a pair a solenoid/deviator, we studied the extraction energy influence, we changed the number of electrodes in order to extract different kind of ions other than protons. This paper will describe briefly the ALISES 3 ion source and will present some results that we gathered in a year.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP04
About •	Received ※ 13 September 2024 — Revised ※ 04 February 2025 — Accepted ※ 06 February 2025 — Issued ※ 07 May 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP07	Use of a 2.45 GHz ECR ion source for the neutron target demonstrator project	ion-source, solenoid, extraction, neutron	42
	S.V. Melanson, A.M. George, M.P. Dehnel, S. Sumar D-Pace, Nelson, British Columbia, Canada
	D-Pace has licensed a 2.45 GHz ECR ion source from Neutron Therapeutics. The ion source will be used for the Neutron Target Demonstrator project at Los Alamos National Laboratory where 10 mA of singly charge krypton ions at 50 keV are required with a normalized 4-RMS emittance of less than 1 mm·mrad. The goal of the project is to create a reverse kinematics neutron capture reaction with ⁸⁴Kr ions. Due to the high radiation environment that the ion source will be subjected to, a solid state microwave power supply will be used instead of the traditional magnetron for the experiment. The main advantage of the solid state power supply is that the output is transmitted by a coax cable instead of a waveguide, so the power supply can be located a long distance away from the ion source without the need for a complicated and expensive waveguide. The other advantage of the solid state device is that the frequency can be varied from 2.4 GHz to 2.5 GHz. This gives the operator an extra degree of freedom for tuning the ion source and also allows for the use of permanent magnets instead of solenoids while still having the ability to tune the ECR condition. We present how the frequency variation affects the beam parameters with both the solenoid and the permanent magnet versions of the ion source.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP07
About •	Received ※ 14 September 2024 — Revised ※ 17 June 2025 — Accepted ※ 29 June 2025 — Issued ※ 30 June 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP08	Automatic classification of plasma states in an ECR-type ion source	luminosity, network, ECR, ion-source	45
	A. Fernández-Rua, I. Arredondo, R. Justo, P. Usabiaga, J. Feuchtwanger University of the Basque Country (UPV/EHU), Leioa, Spain J. Feuchtwanger Ikerbasque, Bilbao, Spain
	In this paper we present the methodology used to acquire the data needed to obtain and train a neural network that will be used in an ECR source to infer the state of the plasma. All the data is the combination of the control signals and a set of non-intrusive measurements that can be accessed during normal operation. For this purpose, machine learning techniques are explored. First, a set of characterisation experiments are carried out in which the state of the plasma is detected for different operating conditions that are fed to a clustering algorithm. Second, a supervised learning paradigm is adopted to train a neural network that is capable of determining the state of the plasma at different working states. The variables that are controlled are: the input RF power and gas flow, the non-intrusive measurements that are acquired are: transmitted and reflected RF power and a ccd camera is used to measure the relative luminosity of the plasma. Based on these variables the state of the plasma is determined. This methodology has been applied to the low-power ECR source in which low-density hydrogen plasmas are generated at the IZPILab laboratory of the University of the Basque Country.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP08
About •	Received ※ 13 September 2024 — Revised ※ 07 February 2025 — Accepted ※ 28 February 2025 — Issued ※ 25 March 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP11	Continuous data-driven control of the GTS-LHC ion source at CERN	injection, controls, solenoid, linac	56
	V. Kain, B. Rodriguez Mateos, N. Bruchon, D. Küchler CERN, Geneva, Switzerland S. Hirlaender University of Salzburg, Salzburg, Austria
	Recent advances with the CERN infrastructure for machine learning allows to deploy state-of-the-art data-driven control algorithms for stabilising and optimising particle accelerator systems. This contribution summarises the results of the first tests with different continuous control algorithms to optimise the intensity out of the CERN LINAC3 source. The task is particularly challenging due to the different latencies for control parameters that range from instantaneous response, to full response after only ~30 minutes. The next steps and a vision towards full deployment and autonomous source control will also be discussed.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP11
About •	Received ※ 14 September 2024 — Revised ※ 17 September 2024 — Accepted ※ 29 January 2025 — Issued ※ 18 May 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUA1	Design of a new iron plug for the TRIUMF ECRIS charge state booster	injection, booster, GUI, ECR	68
	J.A. Adegun, F. Ames, O.K. Kester TRIUMF, Vancouver, Canada
	Funding: Natural Sciences and Engineering Research Council of Canada (NSERC) and TRIUMF This paper presents an innovative solution to address the issue of asymmetric dipole fields in the injection region of the TRIUMF electron cyclotron resonance ion source charge state booster. The asymmetric fields arise from a wide gap in the booster’s injection soft iron plug, which allows the connection of the RF waveguide to the plasma chamber. Simulations have revealed that singly charged ions, injected for charge breeding, experience deflection and get lost due to the asymmetric magnetic fields instead of being effectively captured by the plasma, thereby diminishing the efficiency of the charge state booster. To rectify this problem, a novel iron plug with an enlarged inner diameter, which allows the RF waveguide to connect to the plasma chamber with no gap was designed. Furthermore, this new design necessitates alterations to the injection electrodes and plasma chamber of the booster. Additionally, the waveguide and gas-inlet windows were repositioned to ensure better RF coupling into the plasma cavity. By eliminating the gap and implementing these design changes, it is anticipated that the TRIUMF charge state booster will operate at the same overall efficiency as other PHOENIX boosters.
	Slides TUA1 [5.636 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUA1
About •	Received ※ 17 September 2024 — Revised ※ 07 October 2024 — Accepted ※ 29 May 2025 — Issued ※ 23 June 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUA2	ECR2 performance upgrades at ATLAS	ECR, ion-source, solenoid, extraction	72
	J.T. McLain, R.C. Vondrasek, R.H. Scott ANL, Lemont, Illinois, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. The user requests for higher beam energies and intensities have driven the decision to upgrade the ECR2 ion source at the Argonne Tandem Linac Accelerator System. Multiple upgrades are in progress with the expected outcome of dramatically increased ECR2 beam intensities and charge state capabilities. The magnetic upgrades include integrating an improved hexapole permanent magnet array [1] that provides the ion source radial fields, reworking the magnetic materials surrounding the plasma chamber, and installing a new cooling system for the electromagnetic solenoids that govern the ion source axial fields. The new hexapole and higher solenoid magnet operating currents will increase the ion source magnetic fields and support the use of 18 GHz RF heating, further increasing the ECR2 beam capabilities. Following these improvements and subsequent source performance, simulations of beam transport devices on the ion source platform will need to be revisited for transmission of high intensity beams. Details of these upgrade projects and simulations of the ion optics are presented. [1] R. Vondrasek, J. McLain, and R. Scott, J. Phys.: Conf. Ser., vol. 2743, p. 012044. 2024.
	Slides TUA2 [2.658 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUA2
About •	Received ※ 13 September 2024 — Revised ※ 25 November 2024 — Accepted ※ 29 January 2025 — Issued ※ 05 June 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUB1	Progress in 3D self-consistent full wave-PIC modelling of space resolved ECR plasma properties	electron, ECR, simulation, ECRIS	76
	A. Pidatella, G.S. Mauro, B. Mishra, E. Naselli, G. Torrisi, D. Mascali INFN-LNS, Catania, Italy A. Galatà, C.S. Gallo INFN-LNL, Legnaro (PD), Italy
	We present updates of a simulation suite to model in-plasma ion-electron dynamics, including self-consistent electromagnetic (EM) wave propagation and ion population kinetics to study atomic processes in ECR plasmas. The EM absorption is modelled by a heuristic collisional term in the cold dielectric tensor. However, we are stepping beyond the cold approximation, modelling the hot tensor with non-collisional RF wave damping. The tool calculates steady-state particle distributions via a full wave-PIC code and solves for collisional-radiative process giving atomic population and charge state distribution. The scheme is general and applicable to many physics’ cases of interest for the ECRIS community, including the build-up of the charge-state-distribution and the plasma emitted X-ray and optical radiation. We present its last updates and future perspectives, using as a case-study the PANDORA scenario. We report about studying in-plasma dynamics of injected metallic species and radioisotopes ionisation efficiency for different injection conditions and plasma parameters. The code is capable of reconstructing space-resolved plasma emissivity, to be directly compared to plasma emission measurements, and modelling plasma-induced modification of radioactivity.
	Slides TUB1 [21.575 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUB1
About •	Received ※ 03 October 2024 — Revised ※ 14 October 2024 — Accepted ※ 29 January 2025 — Issued ※ 01 May 2025
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	electron, extraction, ion-source, injection	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)

TUD1	Time-resolved measurement of ion beam energy spread variation due to kinetic plasma instabilities in CW and pulsed operation of an ECRIS	ECR, ECRIS, operation, electron	86
	V. Toivanen, H.A. Koivisto University of Jyväskylä, Jyväskylä, Finland J.O. Huovila University of Eastern Finland, Joensuu, Finland O.A. Tarvainen STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The energy spread of ion beams extracted from Electron Cyclotron Resonance (ECR) ion sources is influenced by plasma conditions such as the plasma potential, and effects taking place in the beam formation region. Kinetic plasma instabilities have a significant impact on the plasma properties, and consequently on the ion beam energy spread. We present experimental results of time-resolved energy spread behaviour when kinetic plasma instabilities are present in CW and pulsed operation of the JYFL 14 GHz ECR ion source. It is shown that the instability-induced energy spread variation corresponds to a momentary plasma potential increase up to several kV from the steady-state value of 10–30 V. The method for measuring the time-resolved energy spread variation is presented, and the consequences of the energy spread and the underlying plasma potential variation for ECRIS operation are discussed.
	Slides TUD1 [3.281 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUD1
About •	Received ※ 13 September 2024 — Revised ※ 18 September 2024 — Accepted ※ 29 March 2025 — Issued ※ 09 May 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP07	Modification of the flexible plasma trap for high-intensity metal ion beams production	extraction, proton, injection, ion-source	105
	C.S. Gallo, A. Galatà INFN-LNL, Legnaro (PD), Italy A. Pidatella, S. Marletta, D. Mascali, G.S. Mauro, S. Passarello, A.D. Russo, G. Torrisi INFN-LNS, Catania, Italy G.R. Mascali Sapienza University of Rome, Rome, Italy
	NQSTI (National Quantum Science and Technology Institute) is the enlarged partnership on QST established under the National Recovery and Resilience Plan (NRRP) funded by the European Union – NextGenerationEU. In this framework, there is a growing interest in the availability of mA beams of singly charged (1+) metallic ions to realise quantum devices. To satisfy this request, the joint INFN Laboratories LNS and LNL proposed to modify the Flexible Plasma Trap (FPT), installed at LNS, thus transforming it into a simple mirror Electron Cyclotron Resonance Ion Source (ECRIS). This contribution describes the various technical solutions that will be adopted, foreseeing novel radial RF and gas/metal injection systems, focusing particularly on the design and simulations of a flexible extraction system capable of handling different beam intensities and ion species. Specifically, the project targets the production of high-intensity beams of singly charged ions such as Fe⁺, and Ba⁺, highlighting the versatility and innovation of the proposed modifications.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUP07
About •	Received ※ 09 October 2024 — Revised ※ 15 October 2024 — Accepted ※ 20 January 2025 — Issued ※ 07 March 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP08	Planned optimization of the ion sources on the HIT test bench	ion-source, resonance, ECR, rfq	109
	T. Winkelmann, A. Peters, B. Naas, R. Cee, Th. Haberer HIT, Heidelberg, Germany
	The Heidelberg Ion Beam Therapy Center (HIT) is a hospital-based treatment facility in Germany. Since the first treatments in 2009, more than 8.500 patients have been irradiated with protons or carbon ions and since July 2021 with helium ions. At HIT, three Supernanogan ion sources supplied by Pantechnik are in operation around the clock for therapy up to 335 days a year. A 4th Supernanogan ECR ion source is installed at the HIT test bench. The test bench is currently being prepared for a measurement campaign that will begin in October. The aim of the investigations is to obtain more beam current for the carbon ions used in therapy by feeding two microwave frequencies in parallel. We expect that this experiment will provide a better understanding of the ionization process in the ion source. In the first step we will feed 14.5 GHz and an extra frequency near the resonance frequency of 14.5 GHz. ±0.5 GHz. In the second step we will feed in 14.5 GHz and 18 GHz. To characterize and evaluate the beam quality in this setup, we will use the pepperpot a 4D emittance measuring device. In addition, it is possible to measure the beam current and the beam profile at the test bench. This article provides an overview of the planned developments on the test bench.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUP08
About •	Received ※ 12 September 2024 — Revised ※ 19 September 2024 — Accepted ※ 30 January 2025 — Issued ※ 14 March 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP09	Characterization of an proton ECR ion source for low beam current	ion-source, experiment, 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
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP10	Optical diagnostic studies to analyse electron cyclotron resonance plasma produced in the GTS-LHC ion source	ion-source, experiment, ECR, 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
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP14	3D simulations of the CAPRICE ECRIS extraction system	simulation, ECR, experiment, 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
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEA1	Characterization of D⁺ species in the 2.45 GHz ECRIS for 14-MeV neutron production	neutron, extraction, ECR, ion-source	136
	S.J. Vala, H.L. Swami, M. Abhangi, R. Kumar, R. Kumar Institute for Plasma Research, Bhat, Gandhinagar, India
	The Institute for Plasma Research has set up a 14-MeV neutron generator facility. The stability, quality, and repeatability of the D⁺ ion beam are critical parameters for ensuring the reliable operation of the neutron generator. Hence, a 2.45 GHz ECR ion source has been installed to produce the deuterium beam. The primary D beam characteristics are assessed by varying extraction voltage, microwave power, gas flow, and solenoid current of the ECRIS. By optimizing these parameters, the maximum design beam current is achieved. The D ion beam contains various species, including D⁺, D₂⁺, D₃⁺, and impurities. Accurate measurement of the D⁺ content within the D ion beam is the key parameter for a neutron generator. Multiple experiments were conducted to determine the D⁺ species and optimise the ECRIS parameters for maximum production of D⁺ species. Two beam current measurement devices, the DCCT and the Faraday Cup, were installed in the beamline to measure the total deuterium beam current and D⁺ beam current, respectively. Notably, the variation in the D⁺ fraction primarily depends on the operating parameters of the ECRIS, such as extraction voltage, microwave power and gas flow. This paper presents the results of the D⁺ ion current as a function of extraction voltage, microwave power, and gas flow rate. Understanding and characterizing the D⁺ species are essential steps toward achieving stable and efficient neutron production in fusion applications.
	Slides WEA1 [3.259 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-WEA1
About •	Received ※ 15 September 2024 — Revised ※ 16 September 2024 — Accepted ※ 29 January 2025 — Issued ※ 26 April 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEA3	A plasma based, charge state stripper for heavy ion accelerators	electron, heavy-ion, target, experiment	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
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEB1	Mixed carbon and helium ion beams for simultaneous heavy ion radiotherapy and radiography: an ion source perspective	experiment, ion-source, 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
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEB2	Applying machine learning techniques to the operation of the superconducting ECR ion source VENUS	operation, ion-source, controls, ECR	152
	D.S. Todd, A. Kireeff, H. Crawford, J.Y. Benitez, M. Salathe, V. Watson, Y.S. Lai LBNL, Berkeley, CA, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Nuclear Physics program under Award Numbers DE-FOA-0002490 and DE-FOA-0002875 An operator of the superconducting ECR ion source VENUS tasked with optimizing the current of a specific ion species or finding a stable operating mode is faced with an operation space composed of ten-to-twenty knobs in which to determine the next move. Machine learning techniques are well-suited to multidimensional optimization spaces. Over the last three years we have been working to employ such techniques with the VENUS ion source. We will present how the introduction of computer control has allowed us to automate tasks such as source baking or to utilize optimization tools to maximize beam currents with no human intervention. Our more recent applications of Bayesian optimization and reinforcement learning to beam current maximization and the maintenance of long term source stability will also be presented. Finally, we will discuss control and diagnostic changes that we have employed to exploit the faster data collection and decision making abilities when VENUS is under computer control.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-WEB2
About •	Received ※ 04 October 2024 — Revised ※ 18 October 2024 — Accepted ※ 26 February 2025 — Issued ※ 24 May 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEB3	Beam intensity prediction using ECR plasma images and machine learning	ECR, ion-source, extraction, operation	156
	Y. Morita, T. Nishi RIKEN, Saitama, Japan A. Kasagi Rikkyo University, Tokyo, Japan K. Kamakura University of Tokyo, Tokyo, Japan N. Oka National Institute of Information and Communications Technology, Tokyo, Japan
	Long-term beam stability is one of the important issues in supplying multivalent heavy ion beams using an Electron Cyclotron Resonance Ion Source (ECRIS). When the beam intensity drops for long-term operation, the ECRIS parameters need to be tuned to restore the original beam intensity. Continuous measurement of the beam intensity using a Faraday cup (FC) is impractical while the beam is in use. We have had to rely on an unreliable method of monitoring the total drain current to estimate the beam intensity during beamtime. To resolve this issue, we propose a new method for predicting the beam intensity at FC using machine learning. Our approach incorporates plasma images, captured through a hole in the beam extraction electrode, and operating parameters as input data for the machine learning model. In short-term test datasets, our model has successfully produced rough predictions of the beam intensity. This presentation will detail the prediction model and its prediction results on the test data.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-WEB3
About •	Received ※ 14 September 2024 — Revised ※ 18 October 2024 — Accepted ※ 02 February 2025 — Issued ※ 04 March 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THA2	Numerical design of an innovative superconducting magnetic trap for probing β-decay in ECR plasmas	injection, electron, ECR, detector	159
	G.S. Mauro, L. Celona, G. Torrisi, A. Pidatella, E. Naselli, F. Russo, B. Mishra, G. Finocchiaro, D. Santonocito, D. Mascali INFN-LNS, Catania, Italy A. Galatà INFN-LNL, Legnaro (PD), Italy
	The main aim of Plasmas for Astrophysics Nuclear Decays Observation and Radiation for Archaeometry (PANDORA) project is to build a flexible magnetic plasma trap where plasma reaches a density nₑ ∼ 10¹¹ – 10¹³ cm⁻³, and a temperature, in units of kT, kTₑ ∼ 0.1 – 30 keV in order to measure, for the first time, nuclear β-decay rates in stellar-like conditions. Here we present the numerical design of the PANDORA magnetic system, carried out by using the commercial simulators OPERA and CST Studio Suite. In particular, we discuss the design choices taken to: 1) obtain the required magnetic field levels at relevant axial and radial positions; 2) avoid the magnetic branches along the plasma chamber wall; 3) find the optimal position for the set of plasma diagnostics that will be employed. The magnetic trap has been conceived to be as large as possible, both in radial and axial directions, in order to exploit the plasma confinement mechanism on a bigger plasmoid volume. The plasma chamber will have a length of 700 mm and a diameter of 280 mm. The magnetic trap tender procedure has been completed in June 2024 and the structure realization is expected to start in late 2024.
	Slides THA2 [6.420 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-THA2
About •	Received ※ 25 January 2025 — Revised ※ 28 January 2025 — Accepted ※ 30 January 2025 — Issued ※ 15 June 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOB1

GANIL ion sources: optimisation for operation

ion-source, ECR, experiment, 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, experiment, ECR, 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)

MOC1

Recent achievements in the production of metallic ion beams with the CAPRICE ECRIS at GSI

operation, ECR, ECRIS, extraction

14

A. Andreev, F. Maimone, J. Mäder, M. Galonska, R. Lang, R. Hollinger
GSI, Darmstadt, Germany

The GSI CAPRICE Electron Cyclotron Resonance Ion Source (ECRIS) provides highly-charged ion beams for various experiments at GSI, enabling the delivery of continuous wave (CW) metallic ion beams with low material consumption, which is crucial for producing high charge state ion beams from rare or extremely rare isotopes such as ⁴⁸Ca. These metallic beams are produced utilizing the thermal evaporation technique by resistively heated ovens. Due to the research groups’ demand for higher beam intensities, increased ion currents of higher charge states are now necessary from the CAPRICE ECRIS. A test campaign was conducted to establish and improve the production of high charge states of enriched ⁵⁴Cr and ⁵⁵Mn ion beams. During the tests, plasma images were captured using a CCD camera to support the operation and enable real-time monitoring of the material consumption. Additionally, a hot screen was used to protect the ceramic insulators in the extraction system from metal deposition, thereby improving the operational stability of the ECRIS. The application of an optical emission spectroscopy to monitor the stability of metallic ion beams during the operation with the resistively heated ovens was also investigated. This contribution presents the operational experience, the intensities and stability achieved for the aforementioned elements. In addition, an update on a recent improvement involving a specialized oven preparation stand for better conditioning of the ovens is given.

Slides MOC1 [3.835 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOC1

About •

Received ※ 13 December 2024 — Revised ※ 21 January 2025 — Accepted ※ 29 January 2025 — Issued ※ 14 May 2025

Cite •

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

MOC2

A novel inductive oven design for the production of high current, metal ion beams

cyclotron, ion-source, target, electron

19

D.S. Todd, J.Y. Benitez
LBNL, Berkeley, CA, USA

Essential to the proposed search for element 120 at LBNL’s 88-Inch Cyclotron is the continual delivery of over a particle microamp of ⁵⁰Ti¹²⁺ for weeks-long campaigns spanning many months. The fully-superconducting ECR ion source VENUS will be the injector source for these runs, and we have developed a new inductive oven design that can survive VENUS’ high magnetic fields while injecting metallic gas into the plasma with high efficiency. The new oven employs a vertical susceptor to permit use with metals that melt before outgassing sufficiently, while also allowing a rotation of the oven’s material exit toward the plasma center for better conversion efficiency to the produced beam. The performance of VENUS with this oven has been outstanding: as reported here, 282 MeV ⁵⁰Ti¹²⁺ beams with stable currents between 1.0 and 1.5 pμA have been delivered for superheavy element searches over multiple ten-day runs.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOC2

About •

Received ※ 04 October 2024 — Revised ※ 10 October 2024 — Accepted ※ 29 January 2025 — Issued ※ 22 June 2025

Cite •

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

MOD1

Development of deuterium-deuterium compact neutron source

target, neutron, vacuum, electron

23

A. Pérez, I. Arredondo, J. Portilla, V. Etxebarria
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
A. Roldán, J. Praena
UGR, Granada, Spain
J. Feuchtwanger
Ikerbasque, Bilbao, Spain

In the present work, we will present the status of the deuterium-deuterium (D-D) neutron source that is being developed in collaboration between the University of Granada and the University of the Basque Country (Spain). Our neutron source consists of an ECR ion source which accelerates a deuteron beam towards a deuterated target. The ionization to achieve the deuterium plasma is achieved by radiating the cylindrical ERC plasma chamber with a magnetron 2.45 GHz signal and an 875 G magnetic field generated by 6 NdFeB magnets located around the plasma chamber. Moreover, a cylindrical alumina RF window is used to keep the vacuum status from the ambient pressure condition inside the WR340 and helping the plasma to ignite. Once the plasma is generated, the deuterons are extracted from the plasma chamber using a Pierce electrode geometry and three other electrostatic lenses, fixed to different negative potentials. The beam is accelerated towards copper target disk with a deuterated titanium mesh fixed to -100 kV which generates the desired neutron radiation. There are several applications of D-D neutron sources across scientific and industrial domains. In case of University of Granada and its deep relation with IFMIF-DONES neutron source, it is worthy to mention that we plan to carry out experiments for determining the cross-sections of relevant isotopes in the studies of IFMIF-DONES to a better simulation of the behaviour of such material under high neutron flux irradiation.

Slides MOD1 [9.890 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOD1

About •

Received ※ 14 September 2024 — Revised ※ 17 September 2024 — Accepted ※ 29 January 2025 — Issued ※ 21 June 2025

Cite •

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

MOP01

Characterization of the 2.45 GHz DREEBIT ECRIS via optical spectroscopy

electron, ECR, ECRIS, ion-source

31

M. Molodtsova, A. Philipp, E. Ritter
DREEBIT, Großröhrsdorf, Germany

ECR ion sources are widely used to provide ions for various experimental setups. DREEBIT GmbH aims to industrialize this type of ion source technology for efficient and reliable use in, e. g., hadron cancer therapy as well as ion implantation of semiconductors. Our goal is to build table-top sized ion sources which can easily be handled as part of a larger machine such as a particle accelerator or target irradiation facility, thereby fulfilling high requirements on beam current, quality, stability as well as reproducibility in serial production. To achieve this, we have already optimized the microwave injection system and magnetic plasma confinement by introducing a simple method to allow for injection of circularly polarized waves and adjusted the magnetic field distribution which led to an 80 % increase of beam current. In the present work, we show how optical emission spectroscopy was used to gain deeper information about the plasma of this specific type of ion source, independent from its ion extraction system. The plasma characterization includes studies of the electron energy distribution and the density of atomic and molecular hydrogen showing that the previous design changes of introducing circularly polarized microwaves and optimizing the magnetic field distribution have led to a well-optimized ECR ion source concerning plasma heating and proton production inside the plasma, indicating how the source performance can be enhanced in further steps.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP01

About •

Received ※ 02 October 2024 — Revised ※ 09 October 2024 — Accepted ※ 29 January 2025 — Issued ※ 07 April 2025

Cite •

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

MOP03

ALISES II source is still alive at CEA Saclay

ion-source, proton, rfq, emittance

35

O. Delferrière, A. Dubois, D. Uriot, J. Schwindling, O. Tuske, Y. Gauthier, Y. Sauce
CEA-IRFU, Gif-sur-Yvette, France
F. Mezei
Mirrotron Ltd., Budapest, Hungary

Developments of ECR intense light ion sources is an important research axis of the Laboratory of Study and Development of Accelerator at CEA-Saclay. Starting from the SILHI proton source in the 90’s to inject the IPHI accelerator, several SILHI-type sources have been realized and installed for high intensity proton or deuteron accelerators for international projects like IFMIF, FAIR or SPIRAL2. From 2011, we started new R&D program on high intensity ECR compact ion sources with the ALISES source family. The results obtained with the first ALISES source prototype gave us the main goals for the design of ALISES II source that runs several months on our 50 kV test bench BETSI and was dismounted at the end of 2016 to upgrade the test bench to 100 kV. But this source was never reinstalled and has been replaced by the ALISES III sources that runs on BETSI up to now. Recently, ALISES II ion source and its equipment is reassembled to be restarted on BETSI for beam characterization before sending it to MIRROTRON factory in Hungary as injector of proton for neutron beam facility. This paper describes the setup on BETSI and proton beam characteristics obtained by emittance measurements, spatial species proportion analysis with Wien filter and current optimization. Installation at MIRROTRON factory is also reported.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP03

About •

Received ※ 13 September 2024 — Revised ※ 16 September 2024 — Accepted ※ 29 January 2025 — Issued ※ 17 February 2025

Cite •

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

MOP04

ALISES v3 ion source in various configuration along the year

ion-source, extraction, proton, electron

39

O. Tuske, A. Dubois, O. Delferrière, Y. Gauthier, Y. Sauce
CEA-IRFU, Gif-sur-Yvette, France

ALISESv3 is a very compact light ion source that has been developed at CEA Saclay in 2018. The easy maintenance procedure of this source allowed us to test many different configurations. On the BETSI test bench equipped with an single Alisson Scanner and a pair a solenoid/deviator, we studied the extraction energy influence, we changed the number of electrodes in order to extract different kind of ions other than protons. This paper will describe briefly the ALISES 3 ion source and will present some results that we gathered in a year.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP04

About •

Received ※ 13 September 2024 — Revised ※ 04 February 2025 — Accepted ※ 06 February 2025 — Issued ※ 07 May 2025

Cite •

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

MOP07

Use of a 2.45 GHz ECR ion source for the neutron target demonstrator project

ion-source, solenoid, extraction, neutron

42

S.V. Melanson, A.M. George, M.P. Dehnel, S. Sumar
D-Pace, Nelson, British Columbia, Canada

D-Pace has licensed a 2.45 GHz ECR ion source from Neutron Therapeutics. The ion source will be used for the Neutron Target Demonstrator project at Los Alamos National Laboratory where 10 mA of singly charge krypton ions at 50 keV are required with a normalized 4-RMS emittance of less than 1 mm·mrad. The goal of the project is to create a reverse kinematics neutron capture reaction with ⁸⁴Kr ions. Due to the high radiation environment that the ion source will be subjected to, a solid state microwave power supply will be used instead of the traditional magnetron for the experiment. The main advantage of the solid state power supply is that the output is transmitted by a coax cable instead of a waveguide, so the power supply can be located a long distance away from the ion source without the need for a complicated and expensive waveguide. The other advantage of the solid state device is that the frequency can be varied from 2.4 GHz to 2.5 GHz. This gives the operator an extra degree of freedom for tuning the ion source and also allows for the use of permanent magnets instead of solenoids while still having the ability to tune the ECR condition. We present how the frequency variation affects the beam parameters with both the solenoid and the permanent magnet versions of the ion source.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP07

About •

Received ※ 14 September 2024 — Revised ※ 17 June 2025 — Accepted ※ 29 June 2025 — Issued ※ 30 June 2025

Cite •

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

MOP08

Automatic classification of plasma states in an ECR-type ion source

luminosity, network, ECR, ion-source

45

A. Fernández-Rua, I. Arredondo, R. Justo, P. Usabiaga, J. Feuchtwanger
University of the Basque Country (UPV/EHU), Leioa, Spain
J. Feuchtwanger
Ikerbasque, Bilbao, Spain

In this paper we present the methodology used to acquire the data needed to obtain and train a neural network that will be used in an ECR source to infer the state of the plasma. All the data is the combination of the control signals and a set of non-intrusive measurements that can be accessed during normal operation. For this purpose, machine learning techniques are explored. First, a set of characterisation experiments are carried out in which the state of the plasma is detected for different operating conditions that are fed to a clustering algorithm. Second, a supervised learning paradigm is adopted to train a neural network that is capable of determining the state of the plasma at different working states. The variables that are controlled are: the input RF power and gas flow, the non-intrusive measurements that are acquired are: transmitted and reflected RF power and a ccd camera is used to measure the relative luminosity of the plasma. Based on these variables the state of the plasma is determined. This methodology has been applied to the low-power ECR source in which low-density hydrogen plasmas are generated at the IZPILab laboratory of the University of the Basque Country.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP08

About •

Received ※ 13 September 2024 — Revised ※ 07 February 2025 — Accepted ※ 28 February 2025 — Issued ※ 25 March 2025

Cite •

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

MOP11

Continuous data-driven control of the GTS-LHC ion source at CERN

injection, controls, solenoid, linac

56

V. Kain, B. Rodriguez Mateos, N. Bruchon, D. Küchler
CERN, Geneva, Switzerland
S. Hirlaender
University of Salzburg, Salzburg, Austria

Recent advances with the CERN infrastructure for machine learning allows to deploy state-of-the-art data-driven control algorithms for stabilising and optimising particle accelerator systems. This contribution summarises the results of the first tests with different continuous control algorithms to optimise the intensity out of the CERN LINAC3 source. The task is particularly challenging due to the different latencies for control parameters that range from instantaneous response, to full response after only ~30 minutes. The next steps and a vision towards full deployment and autonomous source control will also be discussed.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-MOP11

About •

Received ※ 14 September 2024 — Revised ※ 17 September 2024 — Accepted ※ 29 January 2025 — Issued ※ 18 May 2025

Cite •

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

TUA1

Design of a new iron plug for the TRIUMF ECRIS charge state booster

injection, booster, GUI, ECR

68

J.A. Adegun, F. Ames, O.K. Kester
TRIUMF, Vancouver, Canada

Funding: Natural Sciences and Engineering Research Council of Canada (NSERC) and TRIUMF
This paper presents an innovative solution to address the issue of asymmetric dipole fields in the injection region of the TRIUMF electron cyclotron resonance ion source charge state booster. The asymmetric fields arise from a wide gap in the booster’s injection soft iron plug, which allows the connection of the RF waveguide to the plasma chamber. Simulations have revealed that singly charged ions, injected for charge breeding, experience deflection and get lost due to the asymmetric magnetic fields instead of being effectively captured by the plasma, thereby diminishing the efficiency of the charge state booster. To rectify this problem, a novel iron plug with an enlarged inner diameter, which allows the RF waveguide to connect to the plasma chamber with no gap was designed. Furthermore, this new design necessitates alterations to the injection electrodes and plasma chamber of the booster. Additionally, the waveguide and gas-inlet windows were repositioned to ensure better RF coupling into the plasma cavity. By eliminating the gap and implementing these design changes, it is anticipated that the TRIUMF charge state booster will operate at the same overall efficiency as other PHOENIX boosters.

Slides TUA1 [5.636 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUA1

About •

Received ※ 17 September 2024 — Revised ※ 07 October 2024 — Accepted ※ 29 May 2025 — Issued ※ 23 June 2025

Cite •

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

TUA2

ECR2 performance upgrades at ATLAS

ECR, ion-source, solenoid, extraction

72

J.T. McLain, R.C. Vondrasek, R.H. Scott
ANL, Lemont, Illinois, USA

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
The user requests for higher beam energies and intensities have driven the decision to upgrade the ECR2 ion source at the Argonne Tandem Linac Accelerator System. Multiple upgrades are in progress with the expected outcome of dramatically increased ECR2 beam intensities and charge state capabilities. The magnetic upgrades include integrating an improved hexapole permanent magnet array [1] that provides the ion source radial fields, reworking the magnetic materials surrounding the plasma chamber, and installing a new cooling system for the electromagnetic solenoids that govern the ion source axial fields. The new hexapole and higher solenoid magnet operating currents will increase the ion source magnetic fields and support the use of 18 GHz RF heating, further increasing the ECR2 beam capabilities. Following these improvements and subsequent source performance, simulations of beam transport devices on the ion source platform will need to be revisited for transmission of high intensity beams. Details of these upgrade projects and simulations of the ion optics are presented.
[1] R. Vondrasek, J. McLain, and R. Scott, J. Phys.: Conf. Ser., vol. 2743, p. 012044. 2024.

Slides TUA2 [2.658 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUA2

About •

Received ※ 13 September 2024 — Revised ※ 25 November 2024 — Accepted ※ 29 January 2025 — Issued ※ 05 June 2025

Cite •

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

TUB1

Progress in 3D self-consistent full wave-PIC modelling of space resolved ECR plasma properties

electron, ECR, simulation, ECRIS

76

A. Pidatella, G.S. Mauro, B. Mishra, E. Naselli, G. Torrisi, D. Mascali
INFN-LNS, Catania, Italy
A. Galatà, C.S. Gallo
INFN-LNL, Legnaro (PD), Italy

We present updates of a simulation suite to model in-plasma ion-electron dynamics, including self-consistent electromagnetic (EM) wave propagation and ion population kinetics to study atomic processes in ECR plasmas. The EM absorption is modelled by a heuristic collisional term in the cold dielectric tensor. However, we are stepping beyond the cold approximation, modelling the hot tensor with non-collisional RF wave damping. The tool calculates steady-state particle distributions via a full wave-PIC code and solves for collisional-radiative process giving atomic population and charge state distribution. The scheme is general and applicable to many physics’ cases of interest for the ECRIS community, including the build-up of the charge-state-distribution and the plasma emitted X-ray and optical radiation. We present its last updates and future perspectives, using as a case-study the PANDORA scenario. We report about studying in-plasma dynamics of injected metallic species and radioisotopes ionisation efficiency for different injection conditions and plasma parameters. The code is capable of reconstructing space-resolved plasma emissivity, to be directly compared to plasma emission measurements, and modelling plasma-induced modification of radioactivity.

Slides TUB1 [21.575 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUB1

About •

Received ※ 03 October 2024 — Revised ※ 14 October 2024 — Accepted ※ 29 January 2025 — Issued ※ 01 May 2025

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

electron, extraction, ion-source, injection

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)

TUD1

Time-resolved measurement of ion beam energy spread variation due to kinetic plasma instabilities in CW and pulsed operation of an ECRIS

ECR, ECRIS, operation, electron

86

V. Toivanen, H.A. Koivisto
University of Jyväskylä, Jyväskylä, Finland
J.O. Huovila
University of Eastern Finland, Joensuu, Finland
O.A. Tarvainen
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The energy spread of ion beams extracted from Electron Cyclotron Resonance (ECR) ion sources is influenced by plasma conditions such as the plasma potential, and effects taking place in the beam formation region. Kinetic plasma instabilities have a significant impact on the plasma properties, and consequently on the ion beam energy spread. We present experimental results of time-resolved energy spread behaviour when kinetic plasma instabilities are present in CW and pulsed operation of the JYFL 14 GHz ECR ion source. It is shown that the instability-induced energy spread variation corresponds to a momentary plasma potential increase up to several kV from the steady-state value of 10–30 V. The method for measuring the time-resolved energy spread variation is presented, and the consequences of the energy spread and the underlying plasma potential variation for ECRIS operation are discussed.

Slides TUD1 [3.281 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUD1

About •

Received ※ 13 September 2024 — Revised ※ 18 September 2024 — Accepted ※ 29 March 2025 — Issued ※ 09 May 2025

Cite •

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

TUP07

Modification of the flexible plasma trap for high-intensity metal ion beams production

extraction, proton, injection, ion-source

105

C.S. Gallo, A. Galatà
INFN-LNL, Legnaro (PD), Italy
A. Pidatella, S. Marletta, D. Mascali, G.S. Mauro, S. Passarello, A.D. Russo, G. Torrisi
INFN-LNS, Catania, Italy
G.R. Mascali
Sapienza University of Rome, Rome, Italy

NQSTI (National Quantum Science and Technology Institute) is the enlarged partnership on QST established under the National Recovery and Resilience Plan (NRRP) funded by the European Union – NextGenerationEU. In this framework, there is a growing interest in the availability of mA beams of singly charged (1+) metallic ions to realise quantum devices. To satisfy this request, the joint INFN Laboratories LNS and LNL proposed to modify the Flexible Plasma Trap (FPT), installed at LNS, thus transforming it into a simple mirror Electron Cyclotron Resonance Ion Source (ECRIS). This contribution describes the various technical solutions that will be adopted, foreseeing novel radial RF and gas/metal injection systems, focusing particularly on the design and simulations of a flexible extraction system capable of handling different beam intensities and ion species. Specifically, the project targets the production of high-intensity beams of singly charged ions such as Fe⁺, and Ba⁺, highlighting the versatility and innovation of the proposed modifications.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUP07

About •

Received ※ 09 October 2024 — Revised ※ 15 October 2024 — Accepted ※ 20 January 2025 — Issued ※ 07 March 2025

Cite •

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

TUP08

Planned optimization of the ion sources on the HIT test bench

ion-source, resonance, ECR, rfq

109

T. Winkelmann, A. Peters, B. Naas, R. Cee, Th. Haberer
HIT, Heidelberg, Germany

The Heidelberg Ion Beam Therapy Center (HIT) is a hospital-based treatment facility in Germany. Since the first treatments in 2009, more than 8.500 patients have been irradiated with protons or carbon ions and since July 2021 with helium ions. At HIT, three Supernanogan ion sources supplied by Pantechnik are in operation around the clock for therapy up to 335 days a year. A 4th Supernanogan ECR ion source is installed at the HIT test bench. The test bench is currently being prepared for a measurement campaign that will begin in October. The aim of the investigations is to obtain more beam current for the carbon ions used in therapy by feeding two microwave frequencies in parallel. We expect that this experiment will provide a better understanding of the ionization process in the ion source. In the first step we will feed 14.5 GHz and an extra frequency near the resonance frequency of 14.5 GHz. ±0.5 GHz. In the second step we will feed in 14.5 GHz and 18 GHz. To characterize and evaluate the beam quality in this setup, we will use the pepperpot a 4D emittance measuring device. In addition, it is possible to measure the beam current and the beam profile at the test bench. This article provides an overview of the planned developments on the test bench.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUP08

About •

Received ※ 12 September 2024 — Revised ※ 19 September 2024 — Accepted ※ 30 January 2025 — Issued ※ 14 March 2025

Cite •

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

TUP09

Characterization of an proton ECR ion source for low beam current

ion-source, experiment, 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

Cite •

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

TUP10

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

ion-source, experiment, ECR, 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

Cite •

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

TUP14

3D simulations of the CAPRICE ECRIS extraction system

simulation, ECR, experiment, 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

Cite •

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

WEA1

Characterization of D⁺ species in the 2.45 GHz ECRIS for 14-MeV neutron production

neutron, extraction, ECR, ion-source

136

S.J. Vala, H.L. Swami, M. Abhangi, R. Kumar, R. Kumar
Institute for Plasma Research, Bhat, Gandhinagar, India

The Institute for Plasma Research has set up a 14-MeV neutron generator facility. The stability, quality, and repeatability of the D⁺ ion beam are critical parameters for ensuring the reliable operation of the neutron generator. Hence, a 2.45 GHz ECR ion source has been installed to produce the deuterium beam. The primary D beam characteristics are assessed by varying extraction voltage, microwave power, gas flow, and solenoid current of the ECRIS. By optimizing these parameters, the maximum design beam current is achieved. The D ion beam contains various species, including D⁺, D₂⁺, D₃⁺, and impurities. Accurate measurement of the D⁺ content within the D ion beam is the key parameter for a neutron generator. Multiple experiments were conducted to determine the D⁺ species and optimise the ECRIS parameters for maximum production of D⁺ species. Two beam current measurement devices, the DCCT and the Faraday Cup, were installed in the beamline to measure the total deuterium beam current and D⁺ beam current, respectively. Notably, the variation in the D⁺ fraction primarily depends on the operating parameters of the ECRIS, such as extraction voltage, microwave power and gas flow. This paper presents the results of the D⁺ ion current as a function of extraction voltage, microwave power, and gas flow rate. Understanding and characterizing the D⁺ species are essential steps toward achieving stable and efficient neutron production in fusion applications.

Slides WEA1 [3.259 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-WEA1

About •

Received ※ 15 September 2024 — Revised ※ 16 September 2024 — Accepted ※ 29 January 2025 — Issued ※ 26 April 2025

Cite •

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

WEA3

A plasma based, charge state stripper for heavy ion accelerators

electron, heavy-ion, target, experiment

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

Cite •

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

WEB1

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

experiment, ion-source, 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

Cite •

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

WEB2

Applying machine learning techniques to the operation of the superconducting ECR ion source VENUS

operation, ion-source, controls, ECR

152

D.S. Todd, A. Kireeff, H. Crawford, J.Y. Benitez, M. Salathe, V. Watson, Y.S. Lai
LBNL, Berkeley, CA, USA

Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Nuclear Physics program under Award Numbers DE-FOA-0002490 and DE-FOA-0002875
An operator of the superconducting ECR ion source VENUS tasked with optimizing the current of a specific ion species or finding a stable operating mode is faced with an operation space composed of ten-to-twenty knobs in which to determine the next move. Machine learning techniques are well-suited to multidimensional optimization spaces. Over the last three years we have been working to employ such techniques with the VENUS ion source. We will present how the introduction of computer control has allowed us to automate tasks such as source baking or to utilize optimization tools to maximize beam currents with no human intervention. Our more recent applications of Bayesian optimization and reinforcement learning to beam current maximization and the maintenance of long term source stability will also be presented. Finally, we will discuss control and diagnostic changes that we have employed to exploit the faster data collection and decision making abilities when VENUS is under computer control.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-WEB2

About •

Received ※ 04 October 2024 — Revised ※ 18 October 2024 — Accepted ※ 26 February 2025 — Issued ※ 24 May 2025

Cite •

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

WEB3

Beam intensity prediction using ECR plasma images and machine learning

ECR, ion-source, extraction, operation

156

Y. Morita, T. Nishi
RIKEN, Saitama, Japan
A. Kasagi
Rikkyo University, Tokyo, Japan
K. Kamakura
University of Tokyo, Tokyo, Japan
N. Oka
National Institute of Information and Communications Technology, Tokyo, Japan

Long-term beam stability is one of the important issues in supplying multivalent heavy ion beams using an Electron Cyclotron Resonance Ion Source (ECRIS). When the beam intensity drops for long-term operation, the ECRIS parameters need to be tuned to restore the original beam intensity. Continuous measurement of the beam intensity using a Faraday cup (FC) is impractical while the beam is in use. We have had to rely on an unreliable method of monitoring the total drain current to estimate the beam intensity during beamtime. To resolve this issue, we propose a new method for predicting the beam intensity at FC using machine learning. Our approach incorporates plasma images, captured through a hole in the beam extraction electrode, and operating parameters as input data for the machine learning model. In short-term test datasets, our model has successfully produced rough predictions of the beam intensity. This presentation will detail the prediction model and its prediction results on the test data.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-WEB3

About •

Received ※ 14 September 2024 — Revised ※ 18 October 2024 — Accepted ※ 02 February 2025 — Issued ※ 04 March 2025

Cite •

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

THA2

Numerical design of an innovative superconducting magnetic trap for probing β-decay in ECR plasmas

injection, electron, ECR, detector

159

G.S. Mauro, L. Celona, G. Torrisi, A. Pidatella, E. Naselli, F. Russo, B. Mishra, G. Finocchiaro, D. Santonocito, D. Mascali
INFN-LNS, Catania, Italy
A. Galatà
INFN-LNL, Legnaro (PD), Italy

The main aim of Plasmas for Astrophysics Nuclear Decays Observation and Radiation for Archaeometry (PANDORA) project is to build a flexible magnetic plasma trap where plasma reaches a density nₑ ∼ 10¹¹ – 10¹³ cm⁻³, and a temperature, in units of kT, kTₑ ∼ 0.1 – 30 keV in order to measure, for the first time, nuclear β-decay rates in stellar-like conditions. Here we present the numerical design of the PANDORA magnetic system, carried out by using the commercial simulators OPERA and CST Studio Suite. In particular, we discuss the design choices taken to: 1) obtain the required magnetic field levels at relevant axial and radial positions; 2) avoid the magnetic branches along the plasma chamber wall; 3) find the optimal position for the set of plasma diagnostics that will be employed. The magnetic trap has been conceived to be as large as possible, both in radial and axial directions, in order to exploit the plasma confinement mechanism on a bigger plasmoid volume. The plasma chamber will have a length of 700 mm and a diameter of 280 mm. The magnetic trap tender procedure has been completed in June 2024 and the structure realization is expected to start in late 2024.

Slides THA2 [6.420 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-THA2

About •

Received ※ 25 January 2025 — Revised ※ 28 January 2025 — Accepted ※ 30 January 2025 — Issued ※ 15 June 2025

Cite •

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