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The AISHa ion source is an Electron Cyclotron Resonance Ion Source designed to generate high brightness multiply charged ion beams with high reliability, easy operations and maintenance for hadrontheraphy applications. The R performed by the INFN-LNS team during the 2019/2020 has allowed the improvement of the AISHa performances up to 20% for some of the extracted beams: both injection and extraction flanges has been improved and a movable electrode has been installed. The low energy beam transport has been equipped of an Emittance Measurement Unit (EMU), working through the beam wire scanners principle, for the measurement of the vertical and horizontal emittance of the beams of interest for hadrontherapy applications. Beam emittance has been characterized as a function of q/m and of the beam intensity to highlight space charge effects. If necessary, the beam wire scanners can be used for the characterization of the beam shape. The perspectives for further developments and plasma diagnostics will be also highlighted., Proceedings of the 24th International Workshop on ECR Ion Sources, ECRIS2020, East Lansing, MI, USA

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., Proceedings of the 24th International Workshop on ECR Ion Sources, ECRIS2020, East Lansing, MI, USA

The ESS ion source, developed at INFN-LNS and installed at the ESS facility, is fully working and in operation for the linac beam commissioning. The commissioning of the source was done in Catania and in Lund showing high reproducibility related to the beam diagnostic parameters that can be measured with the subset of equipment currently available in Lund. The analysis of the data collected during the commissioning in Catania discloses the possibility to use a new source configuration named High Stability Microwave Discharge Ion Source (HSMDIS), able to improve beam stability and lower the beam emittance. This paper shows the capability to increase the beam current intensity, with preserving beam stability, by changing only the microwave power. Linearity was tested from 10 to 120 mA to be able to provide the lower values needed for the different phases of the accelerator commissioning and higher values for future accelerator development. The source stability is evaluated through intra-pulse stability and pulse-to-pulse stability., Proceedings of the 31st International Linear Accelerator Conference, LINAC2022, Liverpool, UK

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., Proceedings of the 24th International Workshop on ECR Ion Sources, ECRIS2020, East Lansing, MI, USA

ECR Ion Sources are deemed to be among the most performing ion sources feeding particle accelerators, cyclotrons in particular. Improvements of their performances strictly depend on the knowledge of plasma physics in compact magnetic traps. The paper will comment on the results obtained by the INFN-LNS team and international collaborators by means of a multi-diagnostics setup able to monitor the evolution in space and time of several plasma parameters, simultaneously with beam extraction and analysis in the LEBT, in single vs. double frequency operations, including the RF power and magnetic field scalings, and exploring regimes dominated by plasma turbulence. The results are relevant for the operations of existing ion sources and for the design of new ones. Compact magnetic traps fashioned in a similar way of ECRISs can be considered as an experimental environment by itself: we are exploring this opportunity relying to the in-plasma measurements of radionuclides lifetimes (in particular, beta-decaying elements): CosmoChronometers or nuclei involved in the s-process nucleosynthesis are among the case studies, opening new perspectives in the nuclear astrophysics field., Proceedings of the 22nd International Conference on Cyclotrons and their Applications, Cyclotrons2019, Cape Town, South Africa

Several experiments have recently demonstrated that plasma instabilities are powerful limiting factors to the flux of highly charged ion beam extracted from ECRIS. One of the methods for damping the instabilities is to feed the plasma in two frequency heating mode. Since the fundamental physical mechanism is still unclear (diffusion in velocity space? additional confinement?), a deeper experimental investigation is necessary, using multi-diagnostics setups. At ATOMKI-Debrecen the effect on the plasma instabilities of an argon plasma in a 'Two Close Frequencies' scheme has been explored. Spectra of radio-emission from the plasma have been collected for different frequency gaps and relative power balances. The measurements show the plasma self-emitted radiation comes out from the internal plasma (i.e. around the lower frequency) but the instability damping can be effective for some specific combinations of frequency-gap and power balance. Radiofrequency spectra have been collected simultaneously to time-resolved X-ray measurements, triggered by RF bursts produced by the instabilities and detected via a microwave diode connected to a plasma-chamber-immersed multi-pin RF probe., Proceedings of the 23th Int. Workshop on ECR Ion Sources, ECRIS2018, Catania, Italy

The time-resolved characterization of the X-ray emission represents an innovative technique to investigate the heating mechanism of the worm/hot electron component in ECRIS devices. In this paper, the technique has been described and the results of an experimental campaign of measurements in order to characterize the X-rays emission of an axis-symmetric simple mirror trap has been showed. Particular attention has been paid to the ignition and turning off phase. This approach has permitted to estimate confinement time of the warm/hot electron population and put in evidence eventual instability effects during the critical phases. Further developments and perspectives of the technique will be highlighted., Proceedings of the 23th Int. Workshop on ECR Ion Sources, ECRIS2018, Catania, Italy

The high intensity proton source for the European Spallation Source, designed and commissioned at INFN-LNS, is able to produce a stable total current between 40 and 125 mA through an 8 mm extraction aperture, with a proton fraction up to 87%. The best source condition for PS-ESS requirements has been investigated by means of the Optical Emission Spectroscopy (OES). OES has permitted to evaluate simultaneously the H/H2 relative abundances together with electron density and temperature. Results demonstrated that high intensity proton beams are generated in overdense plasma conditions (around 10¹⁸ m⁻³ electron density measured by OES), while electron temperature shows a decreasing trend with power. The results will be discussed and compared with Faraday-cup and Doppler shift measurements. Further upgrades of OES diagnostics will be highlighted., Proceedings of the 23th Int. Workshop on ECR Ion Sources, ECRIS2018, Catania, Italy

The AISHa ion source has been designed to generate high brightness multiply charged ion beams with high reliability, easy operations and maintenance for hadrontheraphy applications. Aisha is a compact ECRIS whose hybrid magnetic system consists of a permanent Halbach-type hexapole magnet and a set of independently energized superconducting He-free coils. The present work shows the results of the ion source commissioning in SFH operational mode (18 GHz) for different ion species. Current status and further improvements will be highlighted., Proceedings of the 23th Int. Workshop on ECR Ion Sources, ECRIS2018, Catania, Italy

The European Spallation Source (ESS) uses a linear accelerator to deliver the high intensity proton beam to the target station for producing intense beams of neutrons. The average beam power is 5 MW with a peak beam power at the target of 125 MW. The normal conducting linear accelerator (linac) operating at 352.21 MHz accelerates a proton beam of 62.5 mA from 0.075 to 90 MeV. It consists of an ion source, Low Energy Beam Transport (LEBT), Radio Frequency Quadrupole (RFQ), Medium Energy Beam Transport (MEBT), and Drift Tube Linac (DTL). The design, construction and testing of those structures is done by European partner labs as an in-kind contribution to the ESS project. This paper presents the status and plans for the ESS normal conducting linac., Proceedings of the 29\textsuperscript{th} Linear Accelerator Conf., LINAC2018, Beijing, China

This work presents the multiple diagnostics characterization of the plasma in an axis-symmetric simple mirror trap as a function of magnetic field profile (mirror ratios and magnetic field gradient), neutral gas pressure and microwave power. The simultaneous use of Optical Emission Spectroscopy, Langmuir Probe and X-ray diagnostics allows the characterization of the whole electron energy distribution function (EEDF), from a few eV to hundreds of keV. Results show non-linear behaviours under small variations of even one source parameter and strong influence of EEDF on the Bmin/BECR ratio. Benefit and next developments will be highlighted., Proceedings of the 23th Int. Workshop on ECR Ion Sources, ECRIS2018, Catania, Italy

The R&D of high gradient radiofrequency (RF) devices is aimed to develop innovative accelerating structures based on new manufacturing techniques and materials in order to construct devices operating with the highest accelerating gradient. Recent studies have shown a large increase in the maximum sustained RF surface electric fields in copper structures operating at cryogenic temperatures. These novel approaches allow significant performance improvements of RF photoinjectors. Indeed the operation at high surface fields results in considerable increase of electron beam brilliance. This increased brilliance requires high field quality in the RF photoinjector and specifically in its power coupler. In this work we present a novel power coupler for the RF photoinjector. The coupler is a compact X-band TM01 mode launcher with a fourfold symmetry which minimized both the dipole and the quadrupole RF components., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

At the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS), the beam commissioning of the high intensity Proton Source for the European Spallation Source (PS-ESS) was completed in November 2017. All requirements have been satisfied and certified by the European Spallation Source (ESS). In the last step of the commissioning a complete characterization of the source has been carried out and some results are hereinafter reported. The shipment of the source was done in December 2017, followed by the installation in January while the beam commissioning is foreseen during summer 2018. The paper describes the final commissioning steps at INFN-LNS, the procedure adopted for a safe transfer of the equipment, the transfer of knowledge needed for the operation and the maintenance., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

Several degree of freedom have been introduced in the design of the proton source (named PS-ESS) and in the Low Energy Beam Transport line (LEBT) developed at INFN-LNS for the European Spallation Source (ESS) project. The beam commissioning was focused on the most important working parameters in order to optimize the beam production performance taking into account the ESS accelerator requirements. The development of a MATLAB custom code able to interact with the EPICS control system framework was needed to optimize the short time available for the beam commissioning. The code was used as an additional high level control system layer able to change all source parameters and read all beam diagnostics output data. More than four hundred of thousand configurations have been explored in a wide range of working parameters. The capability to connect Matlab to EPICS enabled also the developing of a genetic algorithm optimization code able to automatic tune the source towards a precise current value and stability. A dedicated graphical tool was developed for the data analysis. Unexpected benefit come out from this approach that will be shown in this paper., Proceedings of the 16th Int. Conf. on Accelerator and Large Experimental Control Systems, ICALEPCS2017, Barcelona, Spain

At the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS) the beam commissioning of the high intensity Proton Source for the European Spallation Source (PS-ESS) was completed in November 2017. The ESS requires a high intensity proton beam (74 mA pulsed at 14 Hz of repetition rate), with fast Beam pulse rise/fall time (< 20 μs). In order to meet the project requirement, an electrostatic chopping system has been used in the Low Energy Beam Transport (LEBT). The design of the control system was done also to be the main element of the fast beam abort system and taking into account the radiation issue in the accelerator tunnel. This paper describes the performances of the chopper. The experimentally-achieved rise/fall times of the beam pulses measured by using an AC Current Transformer (ACCT) at the end of the LEBT collimator, are presented. An experimental investigation of the effects of different amounts and types of gas injected into the LEBT (for the sake of space charge compensation) has been carried out with respect to the beam and chopper parameters., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

In this work we present the low power RF characterization of a novel TM01 X-band mode launcher for the new generation of high brightness RF photo-injectors. The proposed mode launcher exploits a fourfold symmetry which minimizes both the dipole and the quadrupole fields in order to mitigate the emittance growth in the early stages of the acceleration process. Two identical aluminum mode launchers have been assembled and measured in back-to-back configurations for three different central waveguide lengths. From the back-to-back results we infer the performance of each mode launcher. The low power RF test, performed at the Istituto Nazionale di Fisica Nucleare Laboratori Nazionali del Sud (INFN-LNS), validate both the numerical simulations and the quality of fabrication. An oxygen-free high-conductivity copper version of the device is being manufactured for high power and ultra high vacuum tests that are planned to be conducted at SLAC, Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

At the Istituto Nazionale di Fisica Nucleare Laboratori Nazionali del Sud (INFN-LNS) the beam commissioning of the high intensity Proton Source for the European Spallation Source (PS-ESS) started in November 2016. Beam stability at high current intensity is one of the most important parameter for the first steps of the ongoing commissioning. Promising results were obtained since the first source start with a 6 mm diameter extraction hole. The increase of the extraction hole to 8 mm allowed improving PS-ESS performances and obtaining the values required by the ESS accelerator. In this work, extracted beam current characteristics together with Doppler shift and emittance measurements are presented, as well as the description of the next phases before the installation at ESS in Lund., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

The European Spallation Source (ESS) will deliver first protons on target by mid 2019. Civil construction of the accelerator tunnel has made good progress and will allow starting installation of the normal conducting frond end (NCFE) by end of 2017. To achieve these milestones the design of all major beam line components have been completed and the construction of the subsystems begun. We report on the advancement of the subsystems and the commissioning progress of the microwave discharge Proton Source (PS-ESS)., Proceedings of the 28th Linear Accelerator Conf., LINAC2016, East Lansing, MI, USA

This paper presents the first measurement of plasma density by a K-band microwave polarimetric setup able to measure the magnetoplasma-induced Faraday rotation in a compact size plasma trap. The polarimeter, based on rotating waveguide OMTs (OrthoModeTransducers), has been proven to provide reliable measurements of the plasma density even in the unfavorable conditions 'p ' Lp ' Lc (being 'p, Lp and Lc the probing signal wavelength, the plasma dimension and the plasma chamber length respectively) that complicates the measurements due to multi-patterns caused by reflections of the probing wave on the metallic walls of the plasma chamber. An analysis method has been developed on purpose in order to discriminate the polarization plane rotation due to magnetoplasma Faraday rotation only, excluding the effects of the cavity resonator. The measured density is consistent with the previous plasma density interferometric estimations. The developed method is a powerful tool for probing plasmas in very compact magnetic traps such as Electron Cyclotron Resonance Ion Sources and for in-plasma '-radionuclides' decay studies., Proceedings of the 23th Int. Workshop on ECR Ion Sources, ECRIS2018, Catania, Italy

At INFN-LNS a new superconducting ECRIS named AISHa has been designed with the aim to provide highly charged ion beams with low ripple, high stability and high reproducibility, also fulfilling the needs of hospital installations (e.g. L-He free, easy to use, etc.). It is a hybrid ion source based on a permanent magnet hexapole providing 1.3 T on plasma chamber walls, and four superconducting coils for the axial trapping. The axial magnetic system is very flexible in order to minimize the hot electron component and to optimize the ECR heating by controlling the field gradients and the resonance length. The design of the hexapole aimed to minimize the demagnetization due to SC coils. The magnetic system measurement confirmed the effectiveness of the adopted solutions. Innovative solutions have been also implemented as it concerns the RF system design. It will permit to operate in single/double frequency mode, supported by variable frequency high power klystron generators, thus exploiting at the same time the FTE Frequency Tuning Effect and the Two Frequency Heating. The source has been assembled at the INFN-LNS site and the commissioning phase already started., Proceedings of the 22nd Int. Workshop on ECR Ion Sources, ECRIS2016, Busan, Korea

The CNAO center has been conceived since the beginning with three treatment rooms and an 'experimental room' where research can be carried out without hindering the clinical activity. The room itself was built since the beginning, but the beam line was planned at a second moment in time to give priority to the treatments. The experimental room beam line has now been designed to be 'general purpose', to be used for research in different fields. Possible activities could be, as an example, irradiation of cells, test of beam monitors, development of in-beam monitoring devices or radiation hardness studies. In a second stage a third source will be added to the present two in order to carry on experiments with additional ion species besides the two used presently for treatments, protons and carbon ions. In this paper a description of the design and of the construction status is given., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

Precise knowledge on the density distribution of the Electron Cyclotron Resonance Ion Source plasma is needed by several reasons: i) in order to possibly improve the quality parameters of the extracted ion beam (emittance, brightness) strongly linked to the plasma structure, ii) to correctly investigate the recently observed plasma instabilities and/or the implementation of alternative heating methods (e.g. modal conversion) iii) in order to improve the general microwave-to-plasma coupling efficiency, in view of a microwave-absorption oriented design of future ECRIS. The non-destructive spectroscopic diagnostic methods give information always corresponding to an integration over the whole plasma volume. X-ray imaging by pin-hole camera can partly overcome this limitation. We performed volumetric and space resolved X-ray measurements at the ATOMKI ECRIS operated at lower frequencies than usual. The experimental setup in detail and the methods how the working parameters were selected will be shown. The integrated and photon-counting analyses of the collected plasma images show a strong effect of the frequency and magnetic field on the plasma structure and local energy content., Proceedings of the 22nd Int. Workshop on ECR Ion Sources, ECRIS2016, Busan, Korea

A 2.45 GHz ' 0.1 T microwave discharge Proton Source has been designed and assembled at INFN-LNS for the European Spallation Source (PS-ESS) in order to produce pulsed beams of protons up to 74 mA nominal current, at 75 keV of energy, with a transverse emittance containing 99 % of the nominal proton current below 2.25 π mm mrad and a beam stability of ± 2 %. The challenging performances of the machine have triggered specific studies on the maximization of the proton fraction inside the plasma and of the overall plasma density, including dedicated modelling of the wave-to-plasma interaction and ionization processes. The plasma conditioning phase started in July and excellent RF to plasma coupling, more than 99.5% is evident since the beginning. Reflected power fluctuation less than 0.05 % was measured providing a great starting point to reach the beam stability requested by the ESS accelerator., Proceedings of the 22nd Int. Workshop on ECR Ion Sources, ECRIS2016, Busan, Korea

Charged particle acceleration using ultra-intense and ultra-short laser pulses has gathered a strong interest in the scientific community and it is now one of the most attractive topics in the relativistic laser-plasma interaction research. Indeed, it could represent the future of particle acceleration and open new scenarios in multidisciplinary fields, in particular, medical applications. One of the biggest challenges consists of using, in a future perspective, high intensity laser-target interaction to generate high-energy ions for therapeutic purposes, eventually replacing the old paradigm of acceleration, characterized by huge and complex machines. In this framework, INFN-LNS (Italian Institute of Nuclear Physics, Catania (I)) in collaboration with ELI-Beamline Institute (Dolny Brezany, CZ) will realise, within 2017 the ELIMED (ELI-Beamlines MEDical and multidisciplinary applications) beamline. ELIMED will be the first Users' addressed transport beamline dedicated to the medical and multidisciplinary studies with laser-accelerated ion beams., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

Electron Cyclotron Resonance Ion Sources (ECRIS) are among the candidates to support the growing request of intense beams of multicharged ions. Their further development is related to the availability of new diagnostic tools, nowadays consisting of few types only of devices designed on purpose for such compact machines. Microwave Interferometry is a non-invasive method for plasma diagnostics and represents the best candidate for the whole plasma density measurements. Interferometry in ECR Ion Sources is a challenging task due to their compact size. The typical density range of ECR plasmas (10¹¹-10¹² cm⁻³) causes the probing beam wavelength to be in the order of few centimetres, which is comparable to the chamber radius. The paper describes the design of a new microwave interferometer based on the so-called "frequency sweep" method: the density is here derived by the frequency shift of a beating signal obtained during the fast sweep of both probing and reference microwave signals; inner cavity multipaths contributions can thereby be suppressed by cleaning the spurious frequencies from the beating signal spectrum., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA