ECRIS2020 - List of Keywords (plasma)

Paper	Title	Other Keywords	Page
MOWZO01	FECR Ion Source Development and Challenges	ECR, ion-source, operation, cryogenics	1
	L.T. Sun, Y. Chen, M.Z. Guan, J.W. Guo, J.B. Li, L.B. Li, L.X. Li, W. Lu, E.M. Mei, X.J. Ou, Z. Shen, X.D. Wang, B.M. Wu, W. Wu, C.J. Xin, X.Z. Zhang, H.W. Zhao, S.J. Zheng, L. Zhu IMP/CAS, Lanzhou, People’s Republic of China Z. Shen, L.T. Sun UCAS, Beijing, People’s Republic of China
	FECR or the First 4th generation ECR ion source is under development at Institute of Modern Physics (IMP) since 2015. This ion source is aiming to extract intense highly charged heavy ion beams in the order of emA from the dense plasma heated with 45 GHz microwave power. To provide effective magnetic confinement to the 45 GHz ECR plasma, a state of the art Nb₃Sn magnet with min-B configuration is a straightforward technical path. As there is no much precedent references, it has to be designed, prototyped at IMP through in-house development. Meanwhile, other physics and technical challenges to a 4th generation ECR ion source are also tackled at IMP to find feasible solutions. This paper will give a brief review of the critical issues in the development of FECR ion source. A detailed report on the status of FECR prototype magnet development will be presented.
	Slides MOWZO01 [16.578 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOWZO01
About •	Received ※ 27 September 2020 — Revised ※ 02 October 2020 — Accepted ※ 30 November 2020 — Issue date ※ 07 August 2021
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MOWZO04	GISMO Gasdynamic ECR Ion Source Status: Towards High-Intensity Ion Beams of Superior Quality	extraction, ion-source, ECR, neutron	13
	I. Izotov, A. Bokhanov, E.M. Kiseleva, R.L. Lapin, V. Skalyga, S.S. Vybin IAP/RAS, Nizhny Novgorod, Russia
	Funding: The work was supported by RFBR, grant #20-32-70002, and within the state assignment of the Ministry of Science and Higher Education of the Russian Federation No. 0035-2019-0002. GISMO, a CW high-current quasi-gasdynamic ECR ion source, is under development at the IAP RAS. The quasi-gasdynamic confinement regime, featuring high plasma density (up to 10¹⁴ cm^-3) and moderate electron temperature (~100 eV), allowed to extract pulsed beams of H⁺ and D⁺ ions with current of 450 mA and RMS emittance <0.07 pi mm mrad. It has been already demonstrated that major benefits of quasi-gasdynamic confinement, previously tested in pulsed mode, are scalable to the CW operational mode. In first experiments at GISMO facility, the ion beams were extracted in pulsed mode from the CW plasma of ECR discharge due to technical limitations of cooling circuits. Proton beams with current up to 70 mA were achieved at extraction voltage of 40 kV. A new unique extraction system especially effective for the formation of high current density ion beams was developed. V. Skalyga, I. Izotov, S. Razin, A. Sidorov, S. Golubev, T. Kalvas, H. Koivisto, and O. Tarvainen. Review of Scientific Instruments 85, 02A702 (2014); https://doi.org/10.1063/1.4825074
	Slides MOWZO04 [3.681 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOWZO04
About •	Received ※ 27 September 2020 — Accepted ※ 18 May 2021 — Issue date ※ 02 September 2021
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MOXZO01	Status of the 45 GHz MARS-D ECRIS	ECR, ECRIS, operation, ion-source	17
	D.Z. Xie, J.Y. Benitez, M.K. Covo, A. Hodgkinson, M. Juchno, L. Phair, D.S. Todd, L. Wang LBNL, Berkeley, California, USA
	Funding: This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract number DE-AC02-05CH11231 Development of the MARS-D ECR ion source, a 45 GHz next generation ECRIS using a NbTi MARS-magnet, has been continuously moving forward at LBNL. Recent stress analyses and other key components of the MARS-D ion source have been essentially finalized. This article presents and discusses the status of this new 45 GHz ECR ion source, such as the latest design features and the fabrication plan with funding available in the very near future.
	Slides MOXZO01 [3.661 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOXZO01
About •	Received ※ 25 September 2020 — Revised ※ 02 October 2020 — Accepted ※ 01 December 2020 — Issue date ※ 29 November 2021
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MOYZO01	Imaging in X-ray Ranges to Locally Investigate the Effect of the Two-Close-Frequency Heating in ECRIS Plasmas	ECR, electron, experiment, operation	27
	R. Rácz, S. Biri, Z. Perduk Atomki, Debrecen, Hungary G. Castro, L. Celona, S. Gammino, D. Mascali, M. Mazzaglia, E. Naselli, G. Torrisi INFN/LNS, Catania, Italy A. Galatà INFN/LNL, Legnaro (PD), Italy E. Naselli Catania University, Catania, Italy J. Pálinkás University Debrecen, Debrecen, Hungary
	Plasma instabilities limit the ECR Ion Sources performances in terms of flux of the extracted highly charged ions by causing beam ripple and unstable operation conditions. In a 14 GHz ECRIS (Atomki, Debrecen), the effect on the plasma instabilities in an Argon plasma at Two Close Frequencies heating scheme (the frequency gap is smaller than 1 GHz) has been explored. A special multi-diagnostic setup [1, 2] has been designed and implemented consisting of detectors for the simultaneous collection of plasma radio-self-emission and of high spatial resolution X-ray images in the 500 eV - 20 keV energy domain (using an X-ray pin-hole camera setup). We present the comparison of plasma structural changes as observed from X-ray images in single and double-frequency operations. The latter has been particularly correlated to the confinement and velocity anisotropy, also by considering results coming from numerical simulations. [1] S. Biri et al. Journal of Instrumentation 13(11):C11016 DOI: 10.1088/1748-0221/13/11/C11016 [2] E. Naselli et. al. Journal of Instrumentation 14(10):C10008 DOI: 10.1088/1748-0221/14/10/C10008
	Slides MOYZO01 [7.325 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOYZO01
About •	Received ※ 25 September 2020 — Revised ※ 11 November 2020 — Accepted ※ 17 December 2020 — Issue date ※ 24 January 2021
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MOYZO02	High Resolution X-ray Imaging as a Powerful Diagnostics Tool to Investigate ECRIS Plasma Structure and Confinement Dynamics	photon, ECR, electron, ion-source	32
	E. Naselli, G. Castro, L. Celona, S. Gammino, D. Mascali, M. Mazzaglia, G. Torrisi INFN/LNS, Catania, Italy S. Biri, Z. Perduk, R. Rácz Atomki, Debrecen, Hungary A. Galatà INFN/LNL, Legnaro (PD), Italy E. Naselli Catania University, Catania, Italy J. Pálinkás DU, Debrecen, Hungary
	High resolution spatially-resolved X-ray spectroscopy, by means of a X-ray pin-hole camera setup* ** operating in the 0.5-20 keV energy domain, is a very powerful method for ECRIS plasma structure evaluation. We present the setup installed at a 14 GHz ECRIS (ATOMKI, Debrecen), including a multi-layered collimator enabling measurements up to several hundreds of watts of RF pumping power and the achieved spatial and energy resolution (0.5 mm and 300 eV). Results coming by a new algorithm for analyzing Integrated (multi-events detection) and Photon-Counted images (single-event detection) to perform energy-resolved investigation will be described. The analysis permits to investigate High-Dynamic-Range (HDR) and spectrally resolved images, to study the effect of the axial and radial confinement (even separately), the plasma radius, the fluxes of deconfined electrons distinguishing fluorescence lines of the materials of the plasma chamber (Ti, Ta) from plasma (Ar) fluorescence lines. This method allows a detailed characterization of warm electrons, important for ionization, and to quantitatively estimate local plasma density and spectral temperature pixel-by-pixel. S. Biri et al., JINST 13(11):C11016-C11016, DOI:10.1088/1748-0221/13/11/C11016 *E. Naselli et al., JINST 14(10):C10008-C10008, DOI:10.1088/1748-0221/14/10/C10008
	Slides MOYZO02 [26.629 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOYZO02
About •	Received ※ 27 September 2020 — Revised ※ 02 October 2020 — Accepted ※ 18 November 2020 — Issue date ※ 17 December 2020
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MOYZO03	The Relationship Between the Diffusion of Hot Electrons, Plasma Stability, and ECR Ion Source Performance	ECR, electron, ion-source, cyclotron	38
	B.C. Isherwood MSU, East Lansing, Michigan, USA G. Machicoane NSCL, East Lansing, Michigan, USA G. Machicoane FRIB, East Lansing, Michigan, USA
	Funding: This research was made possible by the National Science Foundation under NSF Grant 1632761 and the U.S. Department of Energy Award Number DE-SC0018362. Plasma instabilities complicate the operation of electron cyclotron resonance ion sources. In particular, quasi-periodic losses of electrons from confinement due to kinetic cyclotron instabilities hinder ion source performance. Empirical scaling laws help guide the development of sources away from the most unstable operating points but are poorly understood. Further advancement of ECR ion source technologies requires a deeper understanding of instabilities, scaling laws, and internal processes of the ion source plasma itself. We present here results of an experimental study into these instabilities and scaling laws, and measurements of hot electron diffusion (E > 10 keV) from the 18 GHz SUSI ECRIS at the NSCL. Measurements of the average argon current and the standard deviation of their variations across multiple unstable operating points are shown. These measurements are compared to measurements of electrons that diffuse axially from the plasma chamber. In doing so it will be shown how controlling the diffusion of electrons control the stability of the plasma and optimize the ion source’s performance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOYZO03
About •	Received ※ 30 September 2020 — Revised ※ 20 October 2020 — Accepted ※ 19 January 2021 — Issue date ※ 11 April 2022
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MOZZO02	ECR Discharge in a Single Solenoid Magnetic Field as a Source of the Wide-Aperture Dense Plasma Fluxes	solenoid, ECR, extraction, experiment	47
	I. Izotov, A. Bokhanov, S. Golubev, M.Yu. Kazakov, S. Razin, R.A. Shaposhnikov, S.P. Shlepnev, V. Skalyga IAP/RAS, Nizhny Novgorod, Russia
	Funding: The reported study was supported by RFBR, project #19-32-90079, and by Presidential Grants Foundation (Grant #MD-2745.2019.2) Sources of dense plasma fluxes with wide aperture are extensively used in applied science, i.e. surface treatment, and as a part of neutral beam injectors. ECR discharge in a solenoidal magnetic field (i.e. with no magnetic mirrors for plasma confinement), sustained by a powerful radiation of modern gyrotrons is under consideration at IAP RAS as a possible alternative to widely used vacuum arc, RF and helicon discharges. The use of a high frequency radiation (37.5 GHz) allows to obtain a discharge at lower pressure, sustain almost fully ionized plasma with density more than 10¹³ cm^-3, whereas the power on the level of several hundreds of kW allows one to create such a plasma in considerably large volume. In the present work fluxes of hydrogen plasma with the equivalent current density of 750 mA/cm² and the total current of 5 A were obtained. A multi-aperture multi-electrode extraction system design capable of forming the non-divergent ion beam was developed with the use of IBSimu code.
	Slides MOZZO02 [0.681 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOZZO02
About •	Received ※ 27 September 2020 — Revised ※ 30 January 2021 — Accepted ※ 13 May 2021 — Issue date ※ 18 May 2021
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MOZZO03	Stable and Intense ⁴⁸Ca Ion Beam Production With a Microwave Shielded Oven and an Optical Spectrometer as Diagnostic Tool	ECR, ECRIS, ion-source, shielding	50
	F. Maimone, R.H. Hollinger, R. Lang, J. Mäder, P.T. Patchakui, K. Tinschert GSI, Darmstadt, Germany A. Andreev TEMF, TU Darmstadt, Darmstadt, Germany
	The CAPRICE ECRIS installed at the High Charge Injector (HLI) of GSI produces highly charged ion beams from gaseous and metallic elements. A high demand of metal ions comes from the nuclear physics, material re-search, and Super Heavy Element group (SHE), and the most requested element, besides 50Ti, is 48Ca. When this chemical reactive material is deposited inside the plasma chamber at internal components the stability can be com-promised. Furthermore, it is difficult to find a working point to guarantee a long-term stability as the oven re-sponse time and the reaction of the ECRIS are relatively slow. The monitoring by using an Optical Emission Spectrometer (OES) facilitates immediate reactions when-ever plasma instabilities occur. For this reason, a real-time diagnostic system based on an OES has been in-stalled at the ECRIS at HLI for routine operation during the beam-time 2020. The measured spectra revealed a parasitic oven heating by coupled microwaves often com-promising the ion source performance. Therefore, a tung-sten grid has been installed to shield the oven orifice from the coupled microwaves. The results in terms of 48Ca beam intensity and stability are reported here.
	Slides MOZZO03 [11.434 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOZZO03
About •	Received ※ 27 September 2020 — Revised ※ 18 September 2020 — Accepted ※ 08 October 2020 — Issue date ※ 13 October 2020
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MOZZO04	New Metallic Stable Ion Beams for GANIL	ECR, ion-source, injection, experiment	54
	F. Lemagnen, C. Barue, M. Dubois, R. Frigot, N. Lechartier, V. Metayer, B. Osmond GANIL, Caen, France
	GANIL has been producing many stable beams for nearly 40 years. Constant progress has been made in terms of intensity, stability and reliability. The intensity for some stable metallic beams now exceeds or approaches the pµA level at an energy up to 95 MeV/u: 1.14 pµA for 36S (65% enriched) at 77 MeV/u, 0.35 pµA for 58Ni (63%) at 74 MeV/u. The presentation highlights recent results obtained for 28Si, 184W and 130Te using the GANIL ‘s LCO (Large Capacity Oven) on the ECR4 ion source. To produce the tungsten beam, two injection methods were compared. For the first one, we evaporated some tungsten trioxide (WO3) with GANIL ‘s LCO. For the second one, the injection in the plasma chamber was made by using MIVOC (Metallic Ions from VOlatile compounds) with a tungsten hexacarbonyl (W(CO)6) compound. It was the first time that we used metal carbonyl compounds and the result is promising. All the tests have been qualified to obtain the level of intensity and beam stability. Theses good results led us to propose them for Physics experiments.
	Slides MOZZO04 [4.743 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOZZO04
About •	Received ※ 25 September 2020 — Revised ※ 16 December 2020 — Accepted ※ 21 January 2021 — Issue date ※ 18 May 2021
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MOZZO06	Microcontrollers as Gate and Delay Generators for Time Resolved Measurements	electron, ECR, ion-source, cyclotron	57
	B.C. Isherwood MSU, East Lansing, Michigan, USA G. Machicoane FRIB, East Lansing, Michigan, USA
	Funding: This research was made possible by the National Science Foundation under NSF Grant 1632761 and the U.S. Department of Energy Award Number DE-SC0018362. The diffusion of electrons from ECRIS plasmas results in the emission of bremsstrahlung distributions from the plasma chamber. ECRIS bremsstrahlung measurements that are both time- and energy-resolved are often challenging to perform due to the 10’s; 100’s ms timescale that the plasma evolves over. However, the advancement of low-cost microcontrollers over the last decade makes timing and gating photon spectrometers easier. We present a proof of principle measurement which uses an Arduino microcontroller as a gate-and-delay generator for a High Purity Germanium (HPGe) detector. An example plot of the time-resolved bremsstrahlung spectrum, triggered by beam current variation induced by kinetic instabilities, is shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOZZO06
About •	Received ※ 30 September 2020 — Revised ※ 21 October 2020 — Accepted ※ 19 January 2021 — Issue date ※ 23 December 2021
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TUWZO01	Measurements of Plasma Parameters Near Resonance Zones and Peripheral Regions in ECRIS	ECR, dipole, ECRIS, electron	60
	W. Kubo, S. Harisaki, Y. Kato, I. Owada, K. Sato, K. Tsuda Osaka University, Graduate School of Engineering, Osaka, Japan
	We have investigated how to produce multicharged ions efficiently. Recently, we have focused on waves propagations in plasma and conducted the Upper-hybrid Resonance (UHR) experiments. [1] We have also conducted experiments heating by the coaxial semi-dipole antenna to enhance the right-hand polarization wave, which contributes to ECR. [2] Multicharged ion beams have been improved using various means, e.g., the increase of the magnetic field and the microwave frequency, the DC biased plate-tuner, mixing low z gases, and the multiplex frequencies heating. However, the microwave launching position has been empirically determined on conventional ECRIS’s. There is still some room for improvement with the respect to more efficient excitation of the wave propagation. In this research, we estimate the wave propagation near the ECR zone, and in the opposite peripheral region beyond it. We measure plasma parameters in those regions by two Langmuir probes inserted into each location at the same time. In near future, we optimize the microwave-launching in the case of the fundamental frequency for ECR and the second frequency for UHR in order to enhance their incidence to the vacuum chamber. [1]Y. Kato et al, AIP Conf. Proc. 2011, 020005 (2018). [2]W. Kubo, et al, RSI, 2020, 91, 023317 (2020).
	Slides TUWZO01 [5.656 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUWZO01
About •	Received ※ 24 September 2020 — Revised ※ 01 October 2020 — Accepted ※ 03 December 2020 — Issue date ※ 16 February 2022
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TUWZO03	Production of Metallic Ion Beams with Inductive Heating Oven at Institute of Modern Physics	ECR, ion-source, operation, ECRIS	65
	W. Lu, Y.C. Feng, J.W. Guo, W. Huang, L.B. Li, L.X. Li, H.Y. Ma, J.D. Ma, C. Qian, L.T. Sun, W.H. Zhang, X.Z. Zhang, H.W. Zhao IMP/CAS, Lanzhou, People’s Republic of China W. Huang, L.T. Sun UCAS, Beijing, People’s Republic of China C. Qian University of Chinese Academy of Sciences, Beijing, People’s Republic of China
	A High-Temperature Oven (HTO) with inductive heating technology has been developed successfully in 2019 at Institute of Modern Physics. This oven features durable operation temperature of >2000’ inside the tantalum susceptor. By careful design the oven structure, material compatibility and thermal stress issues at high temperature has been successfully handled, which enables the production of >400 e’A U³³⁺ with SECRAL-II. With necessary refinement, this type of oven could also be available with room temperature ECR ion sources, like LECR4 and LECR5. Some improvements in structure have been proposed in this year. The design and testing results will be presented in this contribution. W. Lu, L. T. Sun, C. Qian, L. B. Li, J. W. Guo, W. Huang, X. Z. Zhang, and H. W. Zhao, Rev. Sci. Instrum. 90, 113318 (2019);
	Slides TUWZO03 [7.369 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUWZO03
About •	Received ※ 28 September 2020 — Revised ※ 30 December 2020 — Accepted ※ 18 May 2021 — Issue date ※ 08 October 2021
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TUXZO01	A Proposed Explanation of High-Minimum-B Instabilities	electron, resonance, ECR, ion-source	68
	D.S. Todd, J.Y. Benitez LBNL, Berkeley, California, USA
	It is well-known that electron cyclotron resonance ion sources exhibit instabilities when these sources’ minimum magnetic fields are approximately 80% of the resonant field or greater, but the reasons for this instability have yet to be satisfactorily explained. We show that raising the minimum field makes much faster heating modes accessible at lower energies that invite the onset of kinetic instabilities.
	Slides TUXZO01 [3.566 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUXZO01
About •	Received ※ 28 September 2020 — Revised ※ 06 October 2020 — Accepted ※ 03 December 2020 — Issue date ※ 13 December 2020
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TUYZO01	Advancements in Self-Consistent Modeling of Time- and Space-Dependent Phenomena in ECRIS Plasma	electron, ECR, ECRIS, cyclotron	78
	A. Pidatella, D. Mascali, B. Mishra, E. Naselli, G. Torrisi INFN/LNS, Catania, Italy A. Galatà INFN/LNL, Legnaro (PD), Italy E. Naselli Catania University, Catania, Italy
	Resonant interaction with microwave radiation in ECRIS plasma leads to a strongly anisotropic electron energy distribution function (EEDF), given as a combination of two to three electron populations, with anisotropy that might trigger kinetic instabilities. At the INFN, further efforts have been paid to improve and update self-consistent 3D numerical codes for plasma electrons kinetics. Progresses have opened several perspectives. It is now possible to derive a space-resolved EEDF, providing local information on electron properties. Also, the code has been updated to provide reaction rates of electromagnetic emissions, including X-ray fluorescence. Estimates of the local ion charge state distribution is potentially possible, and first evaluations are ongoing. Dealing with fast-transient mechanisms, such as electromagnetic emission via the electron-cyclotron MASER instability, the code is now updated for locally evaluating the EEDF anisotropy. We will present the collected results, which we believe to have a relevant impact both on the ECRIS plasma physics and on the INFN’s PANDORA project that plans to use ECR plasmas for fundamental studies in Nuclear and AstroNuclear Physics.
	Slides TUYZO01 [25.158 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUYZO01
About •	Received ※ 28 September 2020 — Revised ※ 03 October 2020 — Accepted ※ 21 November 2020 — Issue date ※ 01 December 2020
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TUYZO02	A Guiding Centre Approximation Approach for Simulation Electron Trajectories in ECR and Microwave Ion Sources	electron, ion-source, ECR, GUI	84
	J.A. Méndez, T. Thuillier LPSC, Grenoble Cedex, France T. Minea CNRS LPGP Univ Paris Sud, Orsay, France
	Funding: Work supported by the CNRS under the 80\|PRIME grant This work presents a study on the feasibility of the implementation of the guiding centre (GC) approach in electron cyclotron resonance (ECR) ion sources, with the goal of speeding up the electron’s orbit integration in certain regimes. It is shown that the GC approximation reproduces accurately the trajectory drifts and periodic behaviour of electrons in the minimum-B field. A typical electron orbit far enough from the source’s axis is well reproduced for 1 µs of propagation time, with the GC time-step constrained below 100 ps, giving one order of magnitude gain in computation time with respect to Boris. For an electron orbit close to the axis a disphasement of the electron’s trajectory is observed, but the spatial envelope is conserved. A comparative study analyses electron trajectories in a flatter B-field, that in a microwave discharge ion source, where this method’s drawbacks may be avoided given a smaller magnetic field gradient and a shorter electron lifetime in the plasma chamber. In this regime electron trajectories were very well reproduced by the GC approximation. The time-step was constrained below 10 ns, providing up to 30 times faster integration compared to Boris.
	Slides TUYZO02 [5.829 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUYZO02
About •	Received ※ 28 September 2020 — Revised ※ 21 December 2020 — Accepted ※ 18 May 2021 — Issue date ※ 02 February 2022
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TUYZO03	Electromagnetic Simulation of "plasma-shaped" Plasma Chamber for Innovative ECRIS	cavity, GUI, injection, ECR	90
	G.S. Mauro, O. Leonardi, D. Mascali, A. Pidatella, F. Russo, G. Sorbello, G. Torrisi INFN/LNS, Catania, Italy A. Galatà, C.S. Gallo INFN/LNL, Legnaro (PD), Italy C.S. Gallo UNIFE, Ferrara, Italy G. Sorbello University of Catania, Catania, Italy
	The plasma chamber and injection system design play a fundamental role in ECRISs with the aim to obtain an optimized electromagnetic field configuration able to generate and sustain a plasma with a high energy content. In this work we present the numerical study and the design of an unconventionally-shaped cavity resonator* that possesses some key advantages with respect to the standard cylindrical cavities, usually adopted in ion sources setups. The cavity geometry, whose design has been completed on January 2020, has been inspired by the typical star-shaped ECR plasma, determined by the magnetic field structure. The chamber has been designed by using the commercial softwares CST and COMSOL, with the aim to maximize the on-axis electric field. Moreover, a radically innovative microwaves injection system, consisting in side-coupled slotted waveguides, has been implemented, allowing a better power coupling and a more symmetric power distribution inside the cavity with respect to the standard rectangular waveguides. This new ’plasma-shaped oriented’ design could relevantly improve the performances of the ECRISs while making more compact the overall setup. *This work has been carried out within the Grant 73/IRIS project, supported by INFN (Italian patent pending n. 102020000001756).
	Slides TUYZO03 [5.119 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUYZO03
About •	Received ※ 28 September 2020 — Revised ※ 05 October 2020 — Accepted ※ 18 May 2021 — Issue date ※ 10 December 2021
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TUZZO02	Electron Cyclotron Resonance Ion Source Related Research and Development Work at the Department of Physics, University of Jyväskylä (JYFL)	ECR, ECRIS, electron, ion-source	98
	H.A. Koivisto, B.S. Bhaskar, A. Ikonen, T. Kalvas, S.T. Kosonen, R.J. Kronholm, M.S.P. Marttinen, O.P.I. Timonen, V. Toivanen JYFL, Jyväskylä, Finland J. Angot, B.S. Bhaskar, T. Thuillier LPSC, Grenoble Cedex, France I. Izotov, V. Skalyga IAP/RAS, Nizhny Novgorod, Russia L. Maunoury GANIL, Caen, France O.A. Tarvainen STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Funding: The work has received funding from the Academy of Finland under the Academy of Finland Project funding (No. 315855) and from University Grenoble Alps under EMERGENCE-project. Recent research work of the JYFL ion source team covers multi-diagnostic studies of plasma instabilities, high-resolution plasma optical emission spectroscopy, ion current transient measurements to define the total life-time of a particle in the highly charged plasma. The JYFL team also elaborates the magnetic and technical design of the unconventional ion source named CUBE. The R&D work includes, in addition, the commissioning and operation of the high-performance 18 GHz ECRIS, HIISI. The instability measurements have revealed new information about the parameters affecting the onset of the plasma instabilities and shown that different instability modes exist. The ion-beam transient studies have given information about the cumulative life-time of highly-charged ions convergent with the ion temperatures deduced from the Doppler broadening of emission lines. The CUBE prototype has a minimum-B quadrupole magnetic field topology, similar to ARC-ECRIS, and its all-permanent magnet structure has been optimized for 10 GHz frequency. The CUBE design will be presented along with its commissioning status. The status and operational experience with HIISI will be reported as well.
	Slides TUZZO02 [9.553 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO02
About •	Received ※ 28 September 2020 — Revised ※ 09 November 2020 — Accepted ※ 03 December 2020 — Issue date ※ 05 May 2021
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TUZZO04	Status of the 60 GHz ECR Ion Source Research	ion-source, ECR, experiment, extraction	102
	T. André, J. Angot, M.A. Baylac, P. Sole, T. Thuillier LPSC, Grenoble Cedex, France F. Debray GHMFL, Grenoble, France I. Izotov, V. Skalyga IAP/RAS, Nizhny Novgorod, Russia
	SEISM is a compact ECR ion source operating at 60 GHz developed up to 2014. The prototype uses a magnetic cusp to confine the plasma. This simple magnetic geometry was chosen to allow the use of polyhelix coils (developed at the LNCMI, Grenoble) to generate a strong magnetic confinement featuring a closed ECR surface at 2.1 T. The plasma is sustained by a 300 kW microwave pulse of 1 ms duration and with a 2 Hz repetition rate. Previous experiments at LNCMI have successfully demonstrated the establishment of the nominal magnetic field and the extraction of ion beams with a current density up to ~ 1A/cm². The presence of "afterglow" peaks was also observed, proving the existence of ion confinement in a cusp ECR ion source. The last run was prematurely stopped but the project restarted in 2018 and new experiments are planned in 2021. A new transport beam line has been designed to improve ion beam transport towards the beam detectors. Short- and long-term research plans are presented, including numerical simulations of the beam transport line and future upgrades of the ion source with the main goal to transform the high current density measured into a real high intensity ion beam.
	Slides TUZZO04 [5.933 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO04
About •	Received ※ 28 September 2020 — Revised ※ 15 January 2021 — Accepted ※ 14 February 2021 — Issue date ※ 14 July 2022
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WEWZO03	High Intensity Vanadium Beam Production to Search for New Super-Heavy Element with Z = 119	ECR, ion-source, experiment, ECRIS	118
	T. Nagatomo, Y. Higurashi, O. Kamigaito, T. Nakagawa, J. Ohnishi RIKEN Nishina Center, Wako, Japan
	We have begun searching for the new super-heavy element (SHE) with Z=119 at RIKEN Heavy Ion LINAC (RILAC). To overcome the small production cross section of vanadium (V) beam on the curium target, the project requires a very powerful V beam. In order to optimize the beam intensity of V with the charge state of 13+, we have investigated the effects of the amount of V vapor, the power of 18- and 28-GHz microwaves, and the strength of the mirror field. While no significant effect was seen by changing the mirror field Bext from 1.4 T to 1.6 T, the amount of V vapor and the microwave power strongly affected. Based on the correlation between the V-vapor and the microwave power, we obtained a 600-euA V(13+) beam with the V consumption rate of 24 mg/h and the microwave power of 2.9 kW in order to execute about 1-month SHE experiment. Furthermore, because such strong mirror field enhances the transverse beam emittance, it is important to control the emittance with small reduction of the intensity. We have successfully controlled the beam emittance by using three pairs of slits (triplet slits) in LEBT by eliminating the peripheral beam components in both of the x-x’ and y-y’ phase spaces.
	Slides WEWZO03 [2.981 MB]
	Poster WEWZO03 [13.283 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-WEWZO03
About •	Received ※ 28 September 2020 — Revised ※ 29 October 2020 — Accepted ※ 22 January 2021 — Issue date ※ 18 May 2021
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WEWZO04	Producing Multicharged Ions by Pulse Modulated Microwaves at Mixing Low Z Gases on ECRIS	experiment, ECR, resonance, cyclotron	122
	S. Harisaki, Y. Kato, W. Kubo, I. Owada, K. Sato, K. Tsuda Osaka University, Graduate School of Engineering, Osaka, Japan
	We are aiming at producing various ion beams in ECRIS. In the case of producing multicharged ion beams, we try to enhance loss channel of low Z ions by means of adding pulse modulated microwaves to conventional gas mixing method.* Through these experiments, we explore the feasibility of selectively heating specific ions with pulse modulated microwaves and launching another low frequency RF waves. In gas mixing experiment, we use Helium as low Z gas for production of multicharged Ar and Xenon ion beams. These experiments are conducted by keeping the total pressure constant and changing the mixing ratio of Helium. The time scale of pulsed microwave is typically several to several hundreds of microseconds. We optimize the pulse period and duty ratio for producing multicharged ion beams. These effects are investigated to measure Charge State Distributions (CSDs). Also, we can measure the emittance using wire probe and multi slit attached to Ion Beam Irradiation System (IBIS). ** We estimate the normalized emittance from this measurement to determine index of ion temperature in the ECRIS. In this paper, we mainly describe the results of these active and additive methods at the ECRIS. M. Muramatsu, et al., Review of Scientific Instruments, 87, 02C110(2016). *K. Okumura, et al., Review of Scientific Instruments, 91, 023311(2020).
	Slides WEWZO04 [1.283 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-WEWZO04
About •	Received ※ 24 September 2020 — Revised ※ 27 September 2020 — Accepted ※ 03 December 2020 — Issue date ※ 15 July 2021
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WEYZO02	Design of a 2.45 GHz Surface Wave Plasma Source for Plasma Flood Gun	electron, ECR, ion-source, coupling	143
	S.X. Peng, J.E. Chen, B.J. Cui, Z.Y. Guo, Y.X. Jiang, K. Li, T.H. Ma, J.M. Wen, W.B. Wu, Y. Xu, A.L. Zhang, J.F. Zhang, T. Zhang PKU, Beijing, People’s Republic of China
	Plasma ’ood guns (PFGs) are widely used to neutralize wafer charge during the doping process in modern ion implanters. Compared with traditional dc arc discharge with filament and RF discharge, the microwave driven source that has long lifetime and has no metallic contamination is regarded as a potential choice of PFG [1]. Attempt to develop a large scale PFG based on 2.45 GHz microwave driven sources was launched at Peking University (PKU). A prototype one is a miniaturized 2.45 GHz permanent magnet electron cyclotron resonance (ECR) source to produce point-like electron beam. In previous experiments, more than 8 mA electron beam has been extracted with a ’6 mm extraction hole at an input microwave power of 22 W with argon gas [2]. Recently, studies are focusing on the possibility of producing of ribbon electron beams as PFG with 2.45GHz microwave driven surface wave plasma (SWP) source. A cylindrical chamber surface wave plasma generator with a using cylindrical dielectric waveguide and a 70 mm×3 mm extraction slit was fabricated. The primary test results were obtained. More details of this PFGs will be discussed in this work. References [1] B. Vanderberg, et al. AIP Conference Proceedings, 1496(1), 356 (2012). [2] Yaoxiang Jiang, Shixiang Peng, et al, Review of Scientific Instruments, 91, 033319 (2020).
	Slides WEYZO02 [5.475 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-WEYZO02
About •	Received ※ 28 September 2020 — Revised ※ 29 December 2020 — Accepted ※ 25 April 2022 — Issue date ※ 14 July 2022
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WEZZO01	Role of the 1+ Beam Optics Upstream the SPIRAL1 Charge Breeder	optics, simulation, quadrupole, dipole	146
	L. Maunoury, S. Damoy, M. Dubois, R. Frigot, S. Hormigos, B. Jacquot, O. Kamalou GANIL, Caen, France
	The SPIRAL1 charge breeder (SP1CB) is under opera-tion. Radioactive ion beam (RIB) has already been deliv-ered [1] to Physicist for experiments. Charge breeding efficiencies demonstrated high performances for stable ion beams than RIB’s. The beam optics, prior to the injection of the 1+ ions into the SP1CB, is of prime im-portance [2] for obtaining such high efficiencies. Moreo-ver, the intensities of the RIB’s are so low, and indeed difficult to tune the SP1CB. A stable beam having a close B’ is required to find out the set of optic parameters preceding the tuning of the RIB. Hence, it has been de-cided to focus our effort on the control of 1+ beam optics leading to high charge breeding efficiencies whatever the 1+ mass, energy and Target Ion Source System (TISS) used. This contribution will show the strategy undertaken to overcome that problem and the results obtained. [1] L. Maunoury et al., Proceedings of the 23th Int. Workshop on ECR Ion Sources, Catania, Italy (2018) [2] A. Annaluru, PhD thesis, Université Caen Normandie (2019)
	Slides WEZZO01 [4.375 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-WEZZO01
About •	Received ※ 29 September 2020 — Revised ※ 09 October 2020 — Accepted ※ 03 December 2020 — Issue date ※ 21 January 2021
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WEZZO02	Contaminants Reduction in ECR Charge Breeders by LNL LPSC GANIL Collaboration	vacuum, ECR, injection, extraction	151
	J. Angot, M.A. Baylac, M. Migliore, P. Sole, T. Thuillier LPSC, Grenoble Cedex, France A. Galatà INFN/LNL, Legnaro (PD), Italy L. Maunoury GANIL, Caen, France
	Contaminants reduction in Electron Cyclotron Resonance Charge Breeders (ECRCB) is a key point for the future experiments foreseen at LNL and GANIL Isotope Separation On Line (ISOL) facilities. According to the mass separator resolution set downstream the ECRCB, the radioactive ion beam study can be challenged in case of low production rate. An ongoing collaboration between LNL, LPSC and GANIL laboratories aims to improve the beam purity, acting on all the pollutant causes. Comparative experiments will be done at LPSC using different techniques, like covering the plasma chamber wall with liners of different materials. Different configurations of the ECRCB will also be tested, with the enhancement of the efficiency and charge breeding time parameters as additional objectives. A presentation of this program is proposed together with the recent upgrade of the LPSC 1+N+ test bench, with the aim to improve the vacuum quality.
	Slides WEZZO02 [1.915 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-WEZZO02
About •	Received ※ 29 September 2020 — Revised ※ 01 October 2020 — Accepted ※ 15 October 2020 — Issue date ※ 04 November 2020
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WEZZO10	Electron Cyclotron Emission Imaging of Electron Cyclotron Resonance Ion Source Plasmas	electron, ECR, ECRIS, cyclotron	164
	L.E. Henderson, H.L. Clark, C.A. Gagliardi Texas A&M University, Cyclotron Institute, College Station, Texas, USA D.P. May Texas A&M University Cyclotron Institute, College Station, Texas, USA
	A new imaging system for Electron Cyclotron Resonance Ion Sources (ECRIS) has been designed and is being built. This K- and Ka-band camera will extract localized measurements of absolute energy and relative number density for ECRIS plasma electrons by imaging their Electron Cyclotron Emission (ECE) spectra, as the frequency, shape, and strength of the ECE harmonics correlate directly with the local magnetic field, electron energy, and plasma density. The design of the overall quasi-optical system will be presented, including novel ceramic optics for the radial viewports of the Cyclotron Institute’s ECRIS and metamaterial mirrors with electronically controllable reflectivity. Spatial resolution sufficient to distinguish important plasma regions and temporal resolution sufficient to study dynamic plasma processes is expected.
	Slides WEZZO10 [10.583 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-WEZZO10
About •	Received ※ 28 September 2020 — Revised ※ 07 October 2020 — Accepted ※ 15 October 2020 — Issue date ※ 16 November 2020
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NACB04	Ion Simulations, Recent Upgrades and Tests with Titan’s Cooler Penning Trap	electron, simulation, extraction, injection	181
	R. Silwal, J. Dilling, B.A. Kootte, A.A. Kwiatkowski, S.F. Paul TRIUMF, Vancouver, Canada J. Dilling UBC & TRIUMF, Vancouver, British Columbia, Canada G. Gwinner, B.A. Kootte University of Manitoba, Manitoba, Canada R. Simpson UW/Physics, Waterloo, Ontario, Canada
	TRIUMF’s Ion Trap for Atomic and Nuclear science (TITAN) facility has the only on-line mass measurement Penning trap (MPET) at a radioactive beam facility that uses an electron beam ion trap (EBIT) to enhance mass precision and resolution. EBITs can charge breed exotic isotopes, making them highly charged, thereby improving the precision of atomic mass measurement as the precision scales linearly with the charge state. However, ion bunches charge bred in the EBIT can have larger energy spread, which poses challenges for mass measurements. A cooler Penning trap (CPET) is currently being developed off-line at TITAN to sympathetically cool the highly charged ions (HCI) with a co-trapped electron plasma, prior to their transport to the MPET. To evaluate the integration of the CPET into the TITAN beamline and to optimize the beam transport, ion trajectory simulations were performed. Hardware upgrades motivated by these simulations and previous test measurements were applied to the off-line CPET setup. Ions and electrons were co-trapped for the first time with the CPET. Progress and challenges on the path towards HCI cooling and integration with the on-line beam facility are presented
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-NACB04
About •	Received ※ 17 October 2020 — Revised ※ 23 October 2020 — Accepted ※ 01 December 2020 — Issue date ※ 07 February 2021
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Paper

Title

Other Keywords

Page

MOWZO01

FECR Ion Source Development and Challenges

ECR, ion-source, operation, cryogenics

1

L.T. Sun, Y. Chen, M.Z. Guan, J.W. Guo, J.B. Li, L.B. Li, L.X. Li, W. Lu, E.M. Mei, X.J. Ou, Z. Shen, X.D. Wang, B.M. Wu, W. Wu, C.J. Xin, X.Z. Zhang, H.W. Zhao, S.J. Zheng, L. Zhu
IMP/CAS, Lanzhou, People’s Republic of China
Z. Shen, L.T. Sun
UCAS, Beijing, People’s Republic of China

FECR or the First 4th generation ECR ion source is under development at Institute of Modern Physics (IMP) since 2015. This ion source is aiming to extract intense highly charged heavy ion beams in the order of emA from the dense plasma heated with 45 GHz microwave power. To provide effective magnetic confinement to the 45 GHz ECR plasma, a state of the art Nb₃Sn magnet with min-B configuration is a straightforward technical path. As there is no much precedent references, it has to be designed, prototyped at IMP through in-house development. Meanwhile, other physics and technical challenges to a 4th generation ECR ion source are also tackled at IMP to find feasible solutions. This paper will give a brief review of the critical issues in the development of FECR ion source. A detailed report on the status of FECR prototype magnet development will be presented.

Slides MOWZO01 [16.578 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOWZO01

About •

Received ※ 27 September 2020 — Revised ※ 02 October 2020 — Accepted ※ 30 November 2020 — Issue date ※ 07 August 2021

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MOWZO04

GISMO Gasdynamic ECR Ion Source Status: Towards High-Intensity Ion Beams of Superior Quality

extraction, ion-source, ECR, neutron

13

I. Izotov, A. Bokhanov, E.M. Kiseleva, R.L. Lapin, V. Skalyga, S.S. Vybin
IAP/RAS, Nizhny Novgorod, Russia

Funding: The work was supported by RFBR, grant #20-32-70002, and within the state assignment of the Ministry of Science and Higher Education of the Russian Federation No. 0035-2019-0002.
GISMO, a CW high-current quasi-gasdynamic ECR ion source, is under development at the IAP RAS. The quasi-gasdynamic confinement regime, featuring high plasma density (up to 10¹⁴ cm^-3) and moderate electron temperature (~100 eV), allowed to extract pulsed beams of H⁺ and D⁺ ions with current of 450 mA and RMS emittance <0.07 pi mm mrad*. It has been already demonstrated that major benefits of quasi-gasdynamic confinement, previously tested in pulsed mode, are scalable to the CW operational mode. In first experiments at GISMO facility, the ion beams were extracted in pulsed mode from the CW plasma of ECR discharge due to technical limitations of cooling circuits. Proton beams with current up to 70 mA were achieved at extraction voltage of 40 kV. A new unique extraction system especially effective for the formation of high current density ion beams was developed.
* V. Skalyga, I. Izotov, S. Razin, A. Sidorov, S. Golubev, T. Kalvas, H. Koivisto, and O. Tarvainen. Review of Scientific Instruments 85, 02A702 (2014); https://doi.org/10.1063/1.4825074

Slides MOWZO04 [3.681 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOWZO04

About •

Received ※ 27 September 2020 — Accepted ※ 18 May 2021 — Issue date ※ 02 September 2021

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MOXZO01

Status of the 45 GHz MARS-D ECRIS

ECR, ECRIS, operation, ion-source

17

D.Z. Xie, J.Y. Benitez, M.K. Covo, A. Hodgkinson, M. Juchno, L. Phair, D.S. Todd, L. Wang
LBNL, Berkeley, California, USA

Funding: This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract number DE-AC02-05CH11231
Development of the MARS-D ECR ion source, a 45 GHz next generation ECRIS using a NbTi MARS-magnet, has been continuously moving forward at LBNL. Recent stress analyses and other key components of the MARS-D ion source have been essentially finalized. This article presents and discusses the status of this new 45 GHz ECR ion source, such as the latest design features and the fabrication plan with funding available in the very near future.

Slides MOXZO01 [3.661 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOXZO01

About •

Received ※ 25 September 2020 — Revised ※ 02 October 2020 — Accepted ※ 01 December 2020 — Issue date ※ 29 November 2021

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MOYZO01

Imaging in X-ray Ranges to Locally Investigate the Effect of the Two-Close-Frequency Heating in ECRIS Plasmas

ECR, electron, experiment, operation

27

R. Rácz, S. Biri, Z. Perduk
Atomki, Debrecen, Hungary
G. Castro, L. Celona, S. Gammino, D. Mascali, M. Mazzaglia, E. Naselli, G. Torrisi
INFN/LNS, Catania, Italy
A. Galatà
INFN/LNL, Legnaro (PD), Italy
E. Naselli
Catania University, Catania, Italy
J. Pálinkás
University Debrecen, Debrecen, Hungary

Plasma instabilities limit the ECR Ion Sources performances in terms of flux of the extracted highly charged ions by causing beam ripple and unstable operation conditions. In a 14 GHz ECRIS (Atomki, Debrecen), the effect on the plasma instabilities in an Argon plasma at Two Close Frequencies heating scheme (the frequency gap is smaller than 1 GHz) has been explored. A special multi-diagnostic setup [1, 2] has been designed and implemented consisting of detectors for the simultaneous collection of plasma radio-self-emission and of high spatial resolution X-ray images in the 500 eV - 20 keV energy domain (using an X-ray pin-hole camera setup). We present the comparison of plasma structural changes as observed from X-ray images in single and double-frequency operations. The latter has been particularly correlated to the confinement and velocity anisotropy, also by considering results coming from numerical simulations.
[1] S. Biri et al. Journal of Instrumentation 13(11):C11016 DOI: 10.1088/1748-0221/13/11/C11016
[2] E. Naselli et. al. Journal of Instrumentation 14(10):C10008 DOI: 10.1088/1748-0221/14/10/C10008

Slides MOYZO01 [7.325 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOYZO01

About •

Received ※ 25 September 2020 — Revised ※ 11 November 2020 — Accepted ※ 17 December 2020 — Issue date ※ 24 January 2021

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MOYZO02

High Resolution X-ray Imaging as a Powerful Diagnostics Tool to Investigate ECRIS Plasma Structure and Confinement Dynamics

photon, ECR, electron, ion-source

32

E. Naselli, G. Castro, L. Celona, S. Gammino, D. Mascali, M. Mazzaglia, G. Torrisi
INFN/LNS, Catania, Italy
S. Biri, Z. Perduk, R. Rácz
Atomki, Debrecen, Hungary
A. Galatà
INFN/LNL, Legnaro (PD), Italy
E. Naselli
Catania University, Catania, Italy
J. Pálinkás
DU, Debrecen, Hungary

High resolution spatially-resolved X-ray spectroscopy, by means of a X-ray pin-hole camera setup* ** operating in the 0.5-20 keV energy domain, is a very powerful method for ECRIS plasma structure evaluation. We present the setup installed at a 14 GHz ECRIS (ATOMKI, Debrecen), including a multi-layered collimator enabling measurements up to several hundreds of watts of RF pumping power and the achieved spatial and energy resolution (0.5 mm and 300 eV). Results coming by a new algorithm for analyzing Integrated (multi-events detection) and Photon-Counted images (single-event detection) to perform energy-resolved investigation will be described. The analysis permits to investigate High-Dynamic-Range (HDR) and spectrally resolved images, to study the effect of the axial and radial confinement (even separately), the plasma radius, the fluxes of deconfined electrons distinguishing fluorescence lines of the materials of the plasma chamber (Ti, Ta) from plasma (Ar) fluorescence lines. This method allows a detailed characterization of warm electrons, important for ionization, and to quantitatively estimate local plasma density and spectral temperature pixel-by-pixel.
*S. Biri et al., JINST 13(11):C11016-C11016, DOI:10.1088/1748-0221/13/11/C11016
**E. Naselli et al., JINST 14(10):C10008-C10008, DOI:10.1088/1748-0221/14/10/C10008

Slides MOYZO02 [26.629 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOYZO02

About •

Received ※ 27 September 2020 — Revised ※ 02 October 2020 — Accepted ※ 18 November 2020 — Issue date ※ 17 December 2020

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MOYZO03

The Relationship Between the Diffusion of Hot Electrons, Plasma Stability, and ECR Ion Source Performance

ECR, electron, ion-source, cyclotron

38

B.C. Isherwood
MSU, East Lansing, Michigan, USA
G. Machicoane
NSCL, East Lansing, Michigan, USA
G. Machicoane
FRIB, East Lansing, Michigan, USA

Funding: This research was made possible by the National Science Foundation under NSF Grant 1632761 and the U.S. Department of Energy Award Number DE-SC0018362.
Plasma instabilities complicate the operation of electron cyclotron resonance ion sources. In particular, quasi-periodic losses of electrons from confinement due to kinetic cyclotron instabilities hinder ion source performance. Empirical scaling laws help guide the development of sources away from the most unstable operating points but are poorly understood. Further advancement of ECR ion source technologies requires a deeper understanding of instabilities, scaling laws, and internal processes of the ion source plasma itself. We present here results of an experimental study into these instabilities and scaling laws, and measurements of hot electron diffusion (E > 10 keV) from the 18 GHz SUSI ECRIS at the NSCL. Measurements of the average argon current and the standard deviation of their variations across multiple unstable operating points are shown. These measurements are compared to measurements of electrons that diffuse axially from the plasma chamber. In doing so it will be shown how controlling the diffusion of electrons control the stability of the plasma and optimize the ion source’s performance.

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOYZO03

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Received ※ 30 September 2020 — Revised ※ 20 October 2020 — Accepted ※ 19 January 2021 — Issue date ※ 11 April 2022

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MOZZO02

ECR Discharge in a Single Solenoid Magnetic Field as a Source of the Wide-Aperture Dense Plasma Fluxes

solenoid, ECR, extraction, experiment

47

I. Izotov, A. Bokhanov, S. Golubev, M.Yu. Kazakov, S. Razin, R.A. Shaposhnikov, S.P. Shlepnev, V. Skalyga
IAP/RAS, Nizhny Novgorod, Russia

Funding: The reported study was supported by RFBR, project #19-32-90079, and by Presidential Grants Foundation (Grant #MD-2745.2019.2)
Sources of dense plasma fluxes with wide aperture are extensively used in applied science, i.e. surface treatment, and as a part of neutral beam injectors. ECR discharge in a solenoidal magnetic field (i.e. with no magnetic mirrors for plasma confinement), sustained by a powerful radiation of modern gyrotrons is under consideration at IAP RAS as a possible alternative to widely used vacuum arc, RF and helicon discharges. The use of a high frequency radiation (37.5 GHz) allows to obtain a discharge at lower pressure, sustain almost fully ionized plasma with density more than 10¹³ cm^-3, whereas the power on the level of several hundreds of kW allows one to create such a plasma in considerably large volume. In the present work fluxes of hydrogen plasma with the equivalent current density of 750 mA/cm² and the total current of 5 A were obtained. A multi-aperture multi-electrode extraction system design capable of forming the non-divergent ion beam was developed with the use of IBSimu code.

Slides MOZZO02 [0.681 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOZZO02

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Received ※ 27 September 2020 — Revised ※ 30 January 2021 — Accepted ※ 13 May 2021 — Issue date ※ 18 May 2021

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MOZZO03

Stable and Intense ⁴⁸Ca Ion Beam Production With a Microwave Shielded Oven and an Optical Spectrometer as Diagnostic Tool

ECR, ECRIS, ion-source, shielding

50

F. Maimone, R.H. Hollinger, R. Lang, J. Mäder, P.T. Patchakui, K. Tinschert
GSI, Darmstadt, Germany
A. Andreev
TEMF, TU Darmstadt, Darmstadt, Germany

The CAPRICE ECRIS installed at the High Charge Injector (HLI) of GSI produces highly charged ion beams from gaseous and metallic elements. A high demand of metal ions comes from the nuclear physics, material re-search, and Super Heavy Element group (SHE), and the most requested element, besides 50Ti, is 48Ca. When this chemical reactive material is deposited inside the plasma chamber at internal components the stability can be com-promised. Furthermore, it is difficult to find a working point to guarantee a long-term stability as the oven re-sponse time and the reaction of the ECRIS are relatively slow. The monitoring by using an Optical Emission Spectrometer (OES) facilitates immediate reactions when-ever plasma instabilities occur. For this reason, a real-time diagnostic system based on an OES has been in-stalled at the ECRIS at HLI for routine operation during the beam-time 2020. The measured spectra revealed a parasitic oven heating by coupled microwaves often com-promising the ion source performance. Therefore, a tung-sten grid has been installed to shield the oven orifice from the coupled microwaves. The results in terms of 48Ca beam intensity and stability are reported here.

Slides MOZZO03 [11.434 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOZZO03

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Received ※ 27 September 2020 — Revised ※ 18 September 2020 — Accepted ※ 08 October 2020 — Issue date ※ 13 October 2020

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MOZZO04

New Metallic Stable Ion Beams for GANIL

ECR, ion-source, injection, experiment

54

F. Lemagnen, C. Barue, M. Dubois, R. Frigot, N. Lechartier, V. Metayer, B. Osmond
GANIL, Caen, France

GANIL has been producing many stable beams for nearly 40 years. Constant progress has been made in terms of intensity, stability and reliability. The intensity for some stable metallic beams now exceeds or approaches the pµA level at an energy up to 95 MeV/u: 1.14 pµA for 36S (65% enriched) at 77 MeV/u, 0.35 pµA for 58Ni (63%) at 74 MeV/u. The presentation highlights recent results obtained for 28Si, 184W and 130Te using the GANIL ‘s LCO (Large Capacity Oven) on the ECR4 ion source. To produce the tungsten beam, two injection methods were compared. For the first one, we evaporated some tungsten trioxide (WO3) with GANIL ‘s LCO. For the second one, the injection in the plasma chamber was made by using MIVOC (Metallic Ions from VOlatile compounds) with a tungsten hexacarbonyl (W(CO)6) compound. It was the first time that we used metal carbonyl compounds and the result is promising. All the tests have been qualified to obtain the level of intensity and beam stability. Theses good results led us to propose them for Physics experiments.

Slides MOZZO04 [4.743 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOZZO04

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Received ※ 25 September 2020 — Revised ※ 16 December 2020 — Accepted ※ 21 January 2021 — Issue date ※ 18 May 2021

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MOZZO06

Microcontrollers as Gate and Delay Generators for Time Resolved Measurements

electron, ECR, ion-source, cyclotron

57

B.C. Isherwood
MSU, East Lansing, Michigan, USA
G. Machicoane
FRIB, East Lansing, Michigan, USA

Funding: This research was made possible by the National Science Foundation under NSF Grant 1632761 and the U.S. Department of Energy Award Number DE-SC0018362.
The diffusion of electrons from ECRIS plasmas results in the emission of bremsstrahlung distributions from the plasma chamber. ECRIS bremsstrahlung measurements that are both time- and energy-resolved are often challenging to perform due to the 10’s; 100’s ms timescale that the plasma evolves over. However, the advancement of low-cost microcontrollers over the last decade makes timing and gating photon spectrometers easier. We present a proof of principle measurement which uses an Arduino microcontroller as a gate-and-delay generator for a High Purity Germanium (HPGe) detector. An example plot of the time-resolved bremsstrahlung spectrum, triggered by beam current variation induced by kinetic instabilities, is shown.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-MOZZO06

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Received ※ 30 September 2020 — Revised ※ 21 October 2020 — Accepted ※ 19 January 2021 — Issue date ※ 23 December 2021

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TUWZO01

Measurements of Plasma Parameters Near Resonance Zones and Peripheral Regions in ECRIS

ECR, dipole, ECRIS, electron

60

W. Kubo, S. Harisaki, Y. Kato, I. Owada, K. Sato, K. Tsuda
Osaka University, Graduate School of Engineering, Osaka, Japan

We have investigated how to produce multicharged ions efficiently. Recently, we have focused on waves propagations in plasma and conducted the Upper-hybrid Resonance (UHR) experiments. [1] We have also conducted experiments heating by the coaxial semi-dipole antenna to enhance the right-hand polarization wave, which contributes to ECR. [2] Multicharged ion beams have been improved using various means, e.g., the increase of the magnetic field and the microwave frequency, the DC biased plate-tuner, mixing low z gases, and the multiplex frequencies heating. However, the microwave launching position has been empirically determined on conventional ECRIS’s. There is still some room for improvement with the respect to more efficient excitation of the wave propagation. In this research, we estimate the wave propagation near the ECR zone, and in the opposite peripheral region beyond it. We measure plasma parameters in those regions by two Langmuir probes inserted into each location at the same time. In near future, we optimize the microwave-launching in the case of the fundamental frequency for ECR and the second frequency for UHR in order to enhance their incidence to the vacuum chamber.
[1]Y. Kato et al, AIP Conf. Proc. 2011, 020005 (2018).
[2]W. Kubo, et al, RSI, 2020, 91, 023317 (2020).

Slides TUWZO01 [5.656 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUWZO01

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Received ※ 24 September 2020 — Revised ※ 01 October 2020 — Accepted ※ 03 December 2020 — Issue date ※ 16 February 2022

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TUWZO03

Production of Metallic Ion Beams with Inductive Heating Oven at Institute of Modern Physics

ECR, ion-source, operation, ECRIS

65

W. Lu, Y.C. Feng, J.W. Guo, W. Huang, L.B. Li, L.X. Li, H.Y. Ma, J.D. Ma, C. Qian, L.T. Sun, W.H. Zhang, X.Z. Zhang, H.W. Zhao
IMP/CAS, Lanzhou, People’s Republic of China
W. Huang, L.T. Sun
UCAS, Beijing, People’s Republic of China
C. Qian
University of Chinese Academy of Sciences, Beijing, People’s Republic of China

A High-Temperature Oven (HTO) with inductive heating technology has been developed successfully in 2019 at Institute of Modern Physics. This oven features durable operation temperature of >2000’ inside the tantalum susceptor. By careful design the oven structure, material compatibility and thermal stress issues at high temperature has been successfully handled, which enables the production of >400 e’A U³³⁺ with SECRAL-II*. With necessary refinement, this type of oven could also be available with room temperature ECR ion sources, like LECR4 and LECR5. Some improvements in structure have been proposed in this year. The design and testing results will be presented in this contribution.
*W. Lu, L. T. Sun, C. Qian, L. B. Li, J. W. Guo, W. Huang, X. Z. Zhang, and H. W. Zhao, Rev. Sci. Instrum. 90, 113318 (2019);

Slides TUWZO03 [7.369 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUWZO03

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Received ※ 28 September 2020 — Revised ※ 30 December 2020 — Accepted ※ 18 May 2021 — Issue date ※ 08 October 2021

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TUXZO01

A Proposed Explanation of High-Minimum-B Instabilities

electron, resonance, ECR, ion-source

68

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

It is well-known that electron cyclotron resonance ion sources exhibit instabilities when these sources’ minimum magnetic fields are approximately 80% of the resonant field or greater, but the reasons for this instability have yet to be satisfactorily explained. We show that raising the minimum field makes much faster heating modes accessible at lower energies that invite the onset of kinetic instabilities.

Slides TUXZO01 [3.566 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUXZO01

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Received ※ 28 September 2020 — Revised ※ 06 October 2020 — Accepted ※ 03 December 2020 — Issue date ※ 13 December 2020

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TUYZO01

Advancements in Self-Consistent Modeling of Time- and Space-Dependent Phenomena in ECRIS Plasma

electron, ECR, ECRIS, cyclotron

78

A. Pidatella, D. Mascali, B. Mishra, E. Naselli, G. Torrisi
INFN/LNS, Catania, Italy
A. Galatà
INFN/LNL, Legnaro (PD), Italy
E. Naselli
Catania University, Catania, Italy

Resonant interaction with microwave radiation in ECRIS plasma leads to a strongly anisotropic electron energy distribution function (EEDF), given as a combination of two to three electron populations, with anisotropy that might trigger kinetic instabilities. At the INFN, further efforts have been paid to improve and update self-consistent 3D numerical codes for plasma electrons kinetics. Progresses have opened several perspectives. It is now possible to derive a space-resolved EEDF, providing local information on electron properties. Also, the code has been updated to provide reaction rates of electromagnetic emissions, including X-ray fluorescence. Estimates of the local ion charge state distribution is potentially possible, and first evaluations are ongoing. Dealing with fast-transient mechanisms, such as electromagnetic emission via the electron-cyclotron MASER instability, the code is now updated for locally evaluating the EEDF anisotropy. We will present the collected results, which we believe to have a relevant impact both on the ECRIS plasma physics and on the INFN’s PANDORA project that plans to use ECR plasmas for fundamental studies in Nuclear and AstroNuclear Physics.

Slides TUYZO01 [25.158 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUYZO01

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Received ※ 28 September 2020 — Revised ※ 03 October 2020 — Accepted ※ 21 November 2020 — Issue date ※ 01 December 2020

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TUYZO02

A Guiding Centre Approximation Approach for Simulation Electron Trajectories in ECR and Microwave Ion Sources

electron, ion-source, ECR, GUI

84

J.A. Méndez, T. Thuillier
LPSC, Grenoble Cedex, France
T. Minea
CNRS LPGP Univ Paris Sud, Orsay, France

Funding: Work supported by the CNRS under the 80|PRIME grant
This work presents a study on the feasibility of the implementation of the guiding centre (GC) approach in electron cyclotron resonance (ECR) ion sources, with the goal of speeding up the electron’s orbit integration in certain regimes. It is shown that the GC approximation reproduces accurately the trajectory drifts and periodic behaviour of electrons in the minimum-B field. A typical electron orbit far enough from the source’s axis is well reproduced for 1 µs of propagation time, with the GC time-step constrained below 100 ps, giving one order of magnitude gain in computation time with respect to Boris. For an electron orbit close to the axis a disphasement of the electron’s trajectory is observed, but the spatial envelope is conserved. A comparative study analyses electron trajectories in a flatter B-field, that in a microwave discharge ion source, where this method’s drawbacks may be avoided given a smaller magnetic field gradient and a shorter electron lifetime in the plasma chamber. In this regime electron trajectories were very well reproduced by the GC approximation. The time-step was constrained below 10 ns, providing up to 30 times faster integration compared to Boris.

Slides TUYZO02 [5.829 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUYZO02

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Received ※ 28 September 2020 — Revised ※ 21 December 2020 — Accepted ※ 18 May 2021 — Issue date ※ 02 February 2022

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TUYZO03

Electromagnetic Simulation of "plasma-shaped" Plasma Chamber for Innovative ECRIS

cavity, GUI, injection, ECR

90

G.S. Mauro, O. Leonardi, D. Mascali, A. Pidatella, F. Russo, G. Sorbello, G. Torrisi
INFN/LNS, Catania, Italy
A. Galatà, C.S. Gallo
INFN/LNL, Legnaro (PD), Italy
C.S. Gallo
UNIFE, Ferrara, Italy
G. Sorbello
University of Catania, Catania, Italy

The plasma chamber and injection system design play a fundamental role in ECRISs with the aim to obtain an optimized electromagnetic field configuration able to generate and sustain a plasma with a high energy content. In this work we present the numerical study and the design of an unconventionally-shaped cavity resonator* that possesses some key advantages with respect to the standard cylindrical cavities, usually adopted in ion sources setups. The cavity geometry, whose design has been completed on January 2020, has been inspired by the typical star-shaped ECR plasma, determined by the magnetic field structure. The chamber has been designed by using the commercial softwares CST and COMSOL, with the aim to maximize the on-axis electric field. Moreover, a radically innovative microwaves injection system, consisting in side-coupled slotted waveguides, has been implemented, allowing a better power coupling and a more symmetric power distribution inside the cavity with respect to the standard rectangular waveguides. This new ’plasma-shaped oriented’ design could relevantly improve the performances of the ECRISs while making more compact the overall setup.
*This work has been carried out within the Grant 73/IRIS project, supported by INFN (Italian patent pending n. 102020000001756).

Slides TUYZO03 [5.119 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUYZO03

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Received ※ 28 September 2020 — Revised ※ 05 October 2020 — Accepted ※ 18 May 2021 — Issue date ※ 10 December 2021

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TUZZO02

Electron Cyclotron Resonance Ion Source Related Research and Development Work at the Department of Physics, University of Jyväskylä (JYFL)

ECR, ECRIS, electron, ion-source

98

H.A. Koivisto, B.S. Bhaskar, A. Ikonen, T. Kalvas, S.T. Kosonen, R.J. Kronholm, M.S.P. Marttinen, O.P.I. Timonen, V. Toivanen
JYFL, Jyväskylä, Finland
J. Angot, B.S. Bhaskar, T. Thuillier
LPSC, Grenoble Cedex, France
I. Izotov, V. Skalyga
IAP/RAS, Nizhny Novgorod, Russia
L. Maunoury
GANIL, Caen, France
O.A. Tarvainen
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Funding: The work has received funding from the Academy of Finland under the Academy of Finland Project funding (No. 315855) and from University Grenoble Alps under EMERGENCE-project.
Recent research work of the JYFL ion source team covers multi-diagnostic studies of plasma instabilities, high-resolution plasma optical emission spectroscopy, ion current transient measurements to define the total life-time of a particle in the highly charged plasma. The JYFL team also elaborates the magnetic and technical design of the unconventional ion source named CUBE. The R&D work includes, in addition, the commissioning and operation of the high-performance 18 GHz ECRIS, HIISI. The instability measurements have revealed new information about the parameters affecting the onset of the plasma instabilities and shown that different instability modes exist. The ion-beam transient studies have given information about the cumulative life-time of highly-charged ions convergent with the ion temperatures deduced from the Doppler broadening of emission lines. The CUBE prototype has a minimum-B quadrupole magnetic field topology, similar to ARC-ECRIS, and its all-permanent magnet structure has been optimized for 10 GHz frequency. The CUBE design will be presented along with its commissioning status. The status and operational experience with HIISI will be reported as well.

Slides TUZZO02 [9.553 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO02

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Received ※ 28 September 2020 — Revised ※ 09 November 2020 — Accepted ※ 03 December 2020 — Issue date ※ 05 May 2021

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TUZZO04

Status of the 60 GHz ECR Ion Source Research

ion-source, ECR, experiment, extraction

102

T. André, J. Angot, M.A. Baylac, P. Sole, T. Thuillier
LPSC, Grenoble Cedex, France
F. Debray
GHMFL, Grenoble, France
I. Izotov, V. Skalyga
IAP/RAS, Nizhny Novgorod, Russia

SEISM is a compact ECR ion source operating at 60 GHz developed up to 2014. The prototype uses a magnetic cusp to confine the plasma. This simple magnetic geometry was chosen to allow the use of polyhelix coils (developed at the LNCMI, Grenoble) to generate a strong magnetic confinement featuring a closed ECR surface at 2.1 T. The plasma is sustained by a 300 kW microwave pulse of 1 ms duration and with a 2 Hz repetition rate. Previous experiments at LNCMI have successfully demonstrated the establishment of the nominal magnetic field and the extraction of ion beams with a current density up to ~ 1A/cm². The presence of "afterglow" peaks was also observed, proving the existence of ion confinement in a cusp ECR ion source. The last run was prematurely stopped but the project restarted in 2018 and new experiments are planned in 2021. A new transport beam line has been designed to improve ion beam transport towards the beam detectors. Short- and long-term research plans are presented, including numerical simulations of the beam transport line and future upgrades of the ion source with the main goal to transform the high current density measured into a real high intensity ion beam.

Slides TUZZO04 [5.933 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO04

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Received ※ 28 September 2020 — Revised ※ 15 January 2021 — Accepted ※ 14 February 2021 — Issue date ※ 14 July 2022

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WEWZO03

High Intensity Vanadium Beam Production to Search for New Super-Heavy Element with Z = 119

ECR, ion-source, experiment, ECRIS

118

T. Nagatomo, Y. Higurashi, O. Kamigaito, T. Nakagawa, J. Ohnishi
RIKEN Nishina Center, Wako, Japan

We have begun searching for the new super-heavy element (SHE) with Z=119 at RIKEN Heavy Ion LINAC (RILAC). To overcome the small production cross section of vanadium (V) beam on the curium target, the project requires a very powerful V beam. In order to optimize the beam intensity of V with the charge state of 13+, we have investigated the effects of the amount of V vapor, the power of 18- and 28-GHz microwaves, and the strength of the mirror field. While no significant effect was seen by changing the mirror field Bext from 1.4 T to 1.6 T, the amount of V vapor and the microwave power strongly affected. Based on the correlation between the V-vapor and the microwave power, we obtained a 600-euA V(13+) beam with the V consumption rate of 24 mg/h and the microwave power of 2.9 kW in order to execute about 1-month SHE experiment. Furthermore, because such strong mirror field enhances the transverse beam emittance, it is important to control the emittance with small reduction of the intensity. We have successfully controlled the beam emittance by using three pairs of slits (triplet slits) in LEBT by eliminating the peripheral beam components in both of the x-x’ and y-y’ phase spaces.

Slides WEWZO03 [2.981 MB]

Poster WEWZO03 [13.283 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-WEWZO03

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Received ※ 28 September 2020 — Revised ※ 29 October 2020 — Accepted ※ 22 January 2021 — Issue date ※ 18 May 2021

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WEWZO04

Producing Multicharged Ions by Pulse Modulated Microwaves at Mixing Low Z Gases on ECRIS

experiment, ECR, resonance, cyclotron

122

S. Harisaki, Y. Kato, W. Kubo, I. Owada, K. Sato, K. Tsuda
Osaka University, Graduate School of Engineering, Osaka, Japan

We are aiming at producing various ion beams in ECRIS. In the case of producing multicharged ion beams, we try to enhance loss channel of low Z ions by means of adding pulse modulated microwaves to conventional gas mixing method.* Through these experiments, we explore the feasibility of selectively heating specific ions with pulse modulated microwaves and launching another low frequency RF waves. In gas mixing experiment, we use Helium as low Z gas for production of multicharged Ar and Xenon ion beams. These experiments are conducted by keeping the total pressure constant and changing the mixing ratio of Helium. The time scale of pulsed microwave is typically several to several hundreds of microseconds. We optimize the pulse period and duty ratio for producing multicharged ion beams. These effects are investigated to measure Charge State Distributions (CSDs). Also, we can measure the emittance using wire probe and multi slit attached to Ion Beam Irradiation System (IBIS). ** We estimate the normalized emittance from this measurement to determine index of ion temperature in the ECRIS. In this paper, we mainly describe the results of these active and additive methods at the ECRIS.
*M. Muramatsu, et al., Review of Scientific Instruments, 87, 02C110(2016).
**K. Okumura, et al., Review of Scientific Instruments, 91, 023311(2020).

Slides WEWZO04 [1.283 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-WEWZO04

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Received ※ 24 September 2020 — Revised ※ 27 September 2020 — Accepted ※ 03 December 2020 — Issue date ※ 15 July 2021

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WEYZO02

Design of a 2.45 GHz Surface Wave Plasma Source for Plasma Flood Gun

electron, ECR, ion-source, coupling

143

S.X. Peng, J.E. Chen, B.J. Cui, Z.Y. Guo, Y.X. Jiang, K. Li, T.H. Ma, J.M. Wen, W.B. Wu, Y. Xu, A.L. Zhang, J.F. Zhang, T. Zhang
PKU, Beijing, People’s Republic of China

Plasma ’ood guns (PFGs) are widely used to neutralize wafer charge during the doping process in modern ion implanters. Compared with traditional dc arc discharge with filament and RF discharge, the microwave driven source that has long lifetime and has no metallic contamination is regarded as a potential choice of PFG [1]. Attempt to develop a large scale PFG based on 2.45 GHz microwave driven sources was launched at Peking University (PKU). A prototype one is a miniaturized 2.45 GHz permanent magnet electron cyclotron resonance (ECR) source to produce point-like electron beam. In previous experiments, more than 8 mA electron beam has been extracted with a ’6 mm extraction hole at an input microwave power of 22 W with argon gas [2]. Recently, studies are focusing on the possibility of producing of ribbon electron beams as PFG with 2.45GHz microwave driven surface wave plasma (SWP) source. A cylindrical chamber surface wave plasma generator with a using cylindrical dielectric waveguide and a 70 mm×3 mm extraction slit was fabricated. The primary test results were obtained. More details of this PFGs will be discussed in this work.
References
[1] B. Vanderberg, et al. AIP Conference Proceedings, 1496(1), 356 (2012).
[2] Yaoxiang Jiang, Shixiang Peng, et al, Review of Scientific Instruments, 91, 033319 (2020).

Slides WEYZO02 [5.475 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-WEYZO02

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Received ※ 28 September 2020 — Revised ※ 29 December 2020 — Accepted ※ 25 April 2022 — Issue date ※ 14 July 2022

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WEZZO01

Role of the 1+ Beam Optics Upstream the SPIRAL1 Charge Breeder

optics, simulation, quadrupole, dipole

146

L. Maunoury, S. Damoy, M. Dubois, R. Frigot, S. Hormigos, B. Jacquot, O. Kamalou
GANIL, Caen, France

The SPIRAL1 charge breeder (SP1CB) is under opera-tion. Radioactive ion beam (RIB) has already been deliv-ered [1] to Physicist for experiments. Charge breeding efficiencies demonstrated high performances for stable ion beams than RIB’s. The beam optics, prior to the injection of the 1+ ions into the SP1CB, is of prime im-portance [2] for obtaining such high efficiencies. Moreo-ver, the intensities of the RIB’s are so low, and indeed difficult to tune the SP1CB. A stable beam having a close B’ is required to find out the set of optic parameters preceding the tuning of the RIB. Hence, it has been de-cided to focus our effort on the control of 1+ beam optics leading to high charge breeding efficiencies whatever the 1+ mass, energy and Target Ion Source System (TISS) used. This contribution will show the strategy undertaken to overcome that problem and the results obtained.
[1] L. Maunoury et al., Proceedings of the 23th Int. Workshop on ECR Ion Sources, Catania, Italy (2018)
[2] A. Annaluru, PhD thesis, Université Caen Normandie (2019)

Slides WEZZO01 [4.375 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-WEZZO01

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Received ※ 29 September 2020 — Revised ※ 09 October 2020 — Accepted ※ 03 December 2020 — Issue date ※ 21 January 2021

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WEZZO02

Contaminants Reduction in ECR Charge Breeders by LNL LPSC GANIL Collaboration

vacuum, ECR, injection, extraction

151

J. Angot, M.A. Baylac, M. Migliore, P. Sole, T. Thuillier
LPSC, Grenoble Cedex, France
A. Galatà
INFN/LNL, Legnaro (PD), Italy
L. Maunoury
GANIL, Caen, France

Contaminants reduction in Electron Cyclotron Resonance Charge Breeders (ECRCB) is a key point for the future experiments foreseen at LNL and GANIL Isotope Separation On Line (ISOL) facilities. According to the mass separator resolution set downstream the ECRCB, the radioactive ion beam study can be challenged in case of low production rate. An ongoing collaboration between LNL, LPSC and GANIL laboratories aims to improve the beam purity, acting on all the pollutant causes. Comparative experiments will be done at LPSC using different techniques, like covering the plasma chamber wall with liners of different materials. Different configurations of the ECRCB will also be tested, with the enhancement of the efficiency and charge breeding time parameters as additional objectives. A presentation of this program is proposed together with the recent upgrade of the LPSC 1+N+ test bench, with the aim to improve the vacuum quality.

Slides WEZZO02 [1.915 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-WEZZO02

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Received ※ 29 September 2020 — Revised ※ 01 October 2020 — Accepted ※ 15 October 2020 — Issue date ※ 04 November 2020

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WEZZO10

Electron Cyclotron Emission Imaging of Electron Cyclotron Resonance Ion Source Plasmas

electron, ECR, ECRIS, cyclotron

164

L.E. Henderson, H.L. Clark, C.A. Gagliardi
Texas A&M University, Cyclotron Institute, College Station, Texas, USA
D.P. May
Texas A&M University Cyclotron Institute, College Station, Texas, USA

A new imaging system for Electron Cyclotron Resonance Ion Sources (ECRIS) has been designed and is being built. This K- and Ka-band camera will extract localized measurements of absolute energy and relative number density for ECRIS plasma electrons by imaging their Electron Cyclotron Emission (ECE) spectra, as the frequency, shape, and strength of the ECE harmonics correlate directly with the local magnetic field, electron energy, and plasma density. The design of the overall quasi-optical system will be presented, including novel ceramic optics for the radial viewports of the Cyclotron Institute’s ECRIS and metamaterial mirrors with electronically controllable reflectivity. Spatial resolution sufficient to distinguish important plasma regions and temporal resolution sufficient to study dynamic plasma processes is expected.

Slides WEZZO10 [10.583 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-WEZZO10

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Received ※ 28 September 2020 — Revised ※ 07 October 2020 — Accepted ※ 15 October 2020 — Issue date ※ 16 November 2020

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NACB04

Ion Simulations, Recent Upgrades and Tests with Titan’s Cooler Penning Trap

electron, simulation, extraction, injection

181

R. Silwal, J. Dilling, B.A. Kootte, A.A. Kwiatkowski, S.F. Paul
TRIUMF, Vancouver, Canada
J. Dilling
UBC & TRIUMF, Vancouver, British Columbia, Canada
G. Gwinner, B.A. Kootte
University of Manitoba, Manitoba, Canada
R. Simpson
UW/Physics, Waterloo, Ontario, Canada

TRIUMF’s Ion Trap for Atomic and Nuclear science (TITAN) facility has the only on-line mass measurement Penning trap (MPET) at a radioactive beam facility that uses an electron beam ion trap (EBIT) to enhance mass precision and resolution. EBITs can charge breed exotic isotopes, making them highly charged, thereby improving the precision of atomic mass measurement as the precision scales linearly with the charge state. However, ion bunches charge bred in the EBIT can have larger energy spread, which poses challenges for mass measurements. A cooler Penning trap (CPET) is currently being developed off-line at TITAN to sympathetically cool the highly charged ions (HCI) with a co-trapped electron plasma, prior to their transport to the MPET. To evaluate the integration of the CPET into the TITAN beamline and to optimize the beam transport, ion trajectory simulations were performed. Hardware upgrades motivated by these simulations and previous test measurements were applied to the off-line CPET setup. Ions and electrons were co-trapped for the first time with the CPET. Progress and challenges on the path towards HCI cooling and integration with the on-line beam facility are presented

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-NACB04

About •

Received ※ 17 October 2020 — Revised ※ 23 October 2020 — Accepted ※ 01 December 2020 — Issue date ※ 07 February 2021

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