Santo Gammino

• Research Director at INFN - Istituto Nazionale di Fisica Nucleare

An overview is presented of the progress since 2021 in the construction and scientific programme preparation of the Divertor Tokamak Test (DTT) facility. Licensing for building construction has been granted at the end of 2021. Licensing for Cat. A radiologic source has been also granted in 2022. The construction of the toroidal field magnet system...

Electron Cyclotron Resonance Ion Sources (ECRIS) are widely used for production of highly charged high intensity ion beams for research, medical and industrial applications. ECRIS performances, especially the charge state distribution and beam intensity, depend significantly on the electron energy distribution function that ranges from a few eV to...

The requirements for future accelerator chains need to increase the injected beam brilliance significantly, still keeping high the beam quality in terms of reliability, reproducibility and stability. A roadmap for ion source development may consist of several steps: plasma simulation, multiphysics simulation of each system component, high-level con...

An innovative plasma chamber for Electron Cyclotron Resonance Ion Sources (ECRIS) has been developed at INFN and will soon be installed and tested with the AISHa (Advanced Ion Source for Hadrontherapy) ion source. It consists in inserting a particular liner into the existing chamber, which allows an electrical segmentation of the internal walls of...

The European Electron Cyclotron Resonance Ion Source (ECRIS) community has more than 20 years of experience working together in various EU-funded projects. In the recent project, called ERIBS (European Research Infrastructure – Beam Services), the community will focus on improving ion beam services for the EURO-LABS (European-Laboratories for Accel...

The Advanced Ion Source for Hadrontherapy (AISHa) is an ECR ion source operating at 18 GHz, developed with the aim to produce multiply charged ion beams with low ripple, high stability and reproducibility. Due to its unique peculiarity, it is the most suitable choice for medical applications, but also for nuclear-physics and material experiments. T...

The next years will see the completion of several new facilities at Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud (LNS) opening up new possibilities in the fields of nuclear structure, nuclear dynamics, nuclear astrophysics and applications. These include a new line for high-intensity cyclotron beams, a new facility for in-fl...

A broad range of Nuclear Physics research activities have been carried out at INFN-LNS until the summer 2020, when the accelerators were stopped for the upgrade. The upgrade of LNS is a project mainly funded by a PON-FESR (National Program for Research and Innovation) strategic line for boosting the research infrastructures, having its own goals, t...

Hadrontherapy is a well-known clinical practice to treat an increasing number of oncological pathologies, in particular inoperable or radioresistant cancers, when it is essential to minimize the dose absorbed by healthy tissue, as in pediatrics or brain tumors. Due to its unique peculiarities, the ECR ion sources able to produce multiply charged io...

The Advanced Ion Source for Hadrontherapy (AISHa) is an electron cyclotron resonance ion source operating at 18 GHz, developed at the Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali del Sud, with the aim of producing high intensity and low emittance highly charged ion beams for hadrontherapy purposes. Moreover, thanks to its unique pecul...

In this contribution, the motivations for a Focus Point on the future nuclear physics researches in the Italian laboratories are described. The organization of the preliminary workshops and of the final reports in this series is described.

The Advanced Ion Source for Hadrontherapy (AISHa) is an ECR ion source operating at 18 GHz, developed with the aim of producing high intensity and low emittance highly charged ion beams for hadrontherapy purposes. Due to its unique peculiarities, AISHa is a suitable choice for industrial and scientific applications. In the framework of the INSpIRIT...

A new source for the TANDEM accelerator of LNS has been designed and installed. It is called NESTOR (Noble Elements Source for acceleraTORs) and consists of an ultra-compact ECR microwave discharge type ion source [1] operating around 6 GHz and up to 40 W of RF power, provided by a solid state power amplifier, coupled to a Li-Charge Exchange Cell (...

We hereby report a study on confinement and electron loss dynamics in the magnetic trap of an electron cyclotron resonance ion source using a special multi-diagnostic setup that has allowed the simultaneous collection of plasma radio-self-emission and x-ray images in the range 500 eV–20 keV. Argon plasmas were generated in single- and two-close-fre...

Theoretical predictions as well as experiments performed at storage rings have shown that the lifetimes of β-radionuclides can change significantly as a function of the ionization state. In this paper we describe an innovative approach, based on the use of a compact plasma trap to emulate selected stellar-like conditions. It has been proposed withi...

In the frame of the PANDORA_Gr3 project, aiming at measuring for the first time in-plasma nuclear β-decays of astrophysical interest, an innovative multi-diagnostic approach to correlate plasma parameters to nuclear activity has been proposed [1-3]. This is based on several detectors and techniques (optical emission spectroscopy, RF systems, interf...

Electron Cyclotron Resonance Ion Sources are currently the most efficient ion sources among those used in facilities dedicated to nuclear physics. The need for a more flexible magnetic field and RF injection system suggested to design and develop a different type of plasma trap, named Flexible Plasma Trap (FPT). The magnetic field of FPT is generat...

This paper describes three-dimensional numerical simulations and Radio Frequency (RF) measurements of wave propagation in microwave-heated magnetized plasmas of ion sources. Full-wave solution of Maxwell's equations has been addressed through the Finite Element Method (FEM) commercial software COMSOL. Our numerical model takes into account the stro...

At the Italian National Institute for Nuclear Physics-Southern National Laboratory (INFN-LNS), and in collaboration with the ATOMKI laboratories, an innovative multi-diagnostic system with advanced analytical methods has been designed and implemented. This is based on several detectors and techniques (Optical Emission Spectroscopy, RF systems, inte...

At INFN-LNS, and in collaboration with the ATOMKI laboratories, an innovative multi-diagnostic system with advanced analytical methods has been designed and implemented. This is based on several detectors and techniques (Optical Emission Spectroscopy, RF systems, Interfero-polarimetry, X-ray detectors) and here we focus on high resolution spatially...

In the frame of the PANDORA Gr3 (Plasmas for Astrophysics, Nuclear Decay Observation and Radiation for Archaeometry) project aiming at measuring in-plasma nuclear β-decays of astrophysical interest, a multi-diagnostic approach to correlate plasma parameters to nuclear activity has been performed. High-resolution spatially resolved X-ray spectroscop...

PANDORA (Plasma for Astrophysics, Nuclear Decays Observation and Radiation for Archaeometry) is an experiment aimed at studying β plasma decays. As part of this experiment, it is necessary to implement a multi-diagnostic system that includes the Optical Emission Spectroscopy (OES). PANDORA will operate with plasmas formed by a mixture of light elem...

The European spallation source (ESS) uses a linear accelerator (linac) to deliver the high intensity proton beam to the target station for producing intense beams of neutrons. At the exit of the linac, the proton beam will have 2 GeV energy and 62.5 mA current. The construction of an accelerator with the contribution of different laboratories is no...

Magnetized plasmas in compact traps may become experimental en-vironments for the investigation of nuclear beta-decays of astrophysical inter-est. In the framework of the project PANDORA (Plasmas for Astrophysics, Nuclear Decays Observation and Radiation for Archaeometry) the research ac-tivities are devoted to demonstrate the feasibility of an exp...

Experiments performed on Storage Rings have shown that lifetimes of beta-radionuclides can change dramatically as a function of theionization state. PANDORA (Plasmas for Astrophysics, Nuclear Decay Observation and Radiation for Archaeometry) aims at measuring, for the first time, nuclear β-decay rates in stellar-like conditions, especially for radi...

The ion sources for accelerators devoted to medical applications must provide intense ion beams, with high reproducibility, stability and brightness. AISHa (Advanced Ion Source for Hadron therapy) is a compact ECRIS whose hybrid magnetic system consists of a permanent Halbach-type hexapole magnet and a set of independently energized superconducting...

The Advanced Ion Source for Hadrontherapy (AISHa) has been designed to generate high brightness multiply charged ion beams for hadron therapy applications. AISHa is a compact electron cyclotron resonance ion source whose hybrid magnetic system consists of a permanent Halbach-type hexapole magnet and a set of independently energized superconducting...

All-dielectric electromagnetic band gap (EBG) waveguides structures promise significant improvement of accelerating gradient of laser-driven acceleration with the potential to miniaturize the accelerator itself. In this work we study photonic crystal structures designed for acceleration of relativistic electrons. We explore the performance of the a...

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 accelerati...

Experiments have recently demonstrated that kinetic instabilities occurring in the magnetoplasma are huge limiting factors to the flux of highly charged ion beam extracted from ECR Ion Sources. In the recent past, the two-frequency-heating (TFH) mode has been proven to be potentially able for mitigating the instabilities. Since the fundamental phys...

At the Istituto Nazionale di Fisica Nucleare–Laboratori Nazionali del Sud (INFN-LNS), the commissioning of the high intensity proton source for the European Spallation Source (PS-ESS) has been recently completed. Optical emission spectroscopy measurements carried out with PS-ESS permitted, in a noninvasive way, the evaluation of the electron densit...

Nuclear astrophysics, the union of nuclear physics and astronomy, went through an impressive expansion during the last twenty years. This could be achieved thanks to milestone improvements in astronomical observations, cross section measurements, powerful computer simulations and much refined stellar models. Italian groups are giving quite importan...

Several experiments have shown that the insertion of insulator materials within the plasma chamber may lead to a general improvement of microwave discharge ion source performances. In particular, the insertion of alumina into the chamber walls and borum nitride into extraction and injection flanges permits to increase the extracted current and the...

This work presents the X -ray characterization of the plasma generated in a simple mirror axis symmetric trap as a function of the magnetic field profile. A Si-Pin detector has been used to characterize warm electron population in axial and radial directions at 6.83 GHz. Moreover, the hot electrons emitted in axial direction has been measured by me...

Microwave-to-plasma coupling in ECRIS has been based on the classic scheme of waveguide-to-cylindrical plasma cavity matching. Optimization has been often obtained by empirical adjustments leading to an oversimplified model, though obtaining satisfactory performances. In order to overcome the ECR-heating paradigm, on-purpose design of launchers' se...

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 un...

Multiple frequency heating has been used since the '90 in ECR ion sources as heating schemes able to improve current intensities especially for highly charged ions. More recently "Two Close Frequency Heating", where the frequency gap is comparable with the scale-length of the resonance, has been proposed, expected also to be sensitive to the relati...

This paper describes three-dimensional numerical simulations and Radio Frequency (RF) measurements of wave propagation in microwave-heated magnetized plasmas of ion sources. Full-wave solution of Maxwell’s equations has been addressed through the Finite Element Method (FEM) commercial software COMSOL. Our numerical model takes into account the stro...

Electron Cyclotron Resonance (ECR) plasmas with high density and high temperature are required by the injectors for the Accelerators and by interdisciplinary studies in Astrophysics and Nuclear Astrophysics. Understanding and further developing magnetic traps requires accurate measurements of the physical properties of the confined plasma, such as...

While the mechanism is still not fully clear, the beneficial effect (higher intensity of highly charged ions, stable plasma conditions) of the second microwave injected to the ECR plasma was observed in many laboratories, both with close and far frequencies. Due to the complexity of the phenomena (e.g. interaction of resonant zones, damped instabil...

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), especially in the quasi-flat B field configuration that is typical of Microwave Discharge Ion Sources, and also of neutral gas pressure and microwave...

This paper describes three-dimensional numerical simulations and Radio Frequency (RF) measurements of wave propagation in the microwave-heated magnetized plasmas of ion sources. Our 3D Full-wave numerical model considers the inhomogeneous and anisotropic magnetized plasma medium in the "cold" plasma approximation. Maxwell's equations have been solv...

This paper shows simulations and experimental result of a 1.5 kW waveguide DC‐Break designed for the AISHa ion source in commissioning phase at INFN‐LNS. The DC‐Break was designed to fulfill an insulation of 50 kV, power losses lower than 0.5 dB by considering the compactness as key requirement.

The development and upgrade of ion sources for accelerators depends more and more on the optimization of the microwave-to-plasma coupling. Proton sources require to optimize the Electron Energy Distribution Function (EEDF) in the range of a few tens of eV. Multicharged ions sources require the optimization of EEDF in the keV scale depending on the...

X-ray imaging and numerical simulations demonstrate that the RF power deposition in ECRIS plasmas is not concentrated in the near-axis region, as it would be desirable in order to maximize the ion beam brilliance. There are different arguments to explain this occurrence as due to the symmetry of the plasma chamber. In an “aperture coupled cylindric...

At the Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud (INFN-LNS) the beam commissioning of the high intensity Proton Source (PS-ESS) and the Low Energy Beam Transport (LEBT) line for the European Spallation Source (ESS) has been completed. The official project schedule was satisfied and the packaging for the shipment to Lund w...

The new AISHa ion source has been designed to generate high brightness multiply charged ion beams for hadrontheraphy applications, with high reliability, easy operations and fast maintenance. In order to get a compact machine the radial confinement is provided by a Hallbach-type permanent magnet hexapole structure, while axial confinement is allowe...

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 (74mA pulsed at 14 Hz of repetition rate), with fast Beam pulse rise/fall time (<...

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 struc...

Ion sources are key components of accelerators devoted to different types of medical applications: hadron-therapy facilities (accelerating protons or carbon ions), high-intensity accelerators for boron-neutron capture therapy (using intense proton beams), and facilities for isotope production (using different ion species). The three types of applic...

Magnetoplasmas in ECR-Ion Sources are excited from gaseous elements or vapours by microwaves in the range 2.45–28 GHz via Electron Cyclotron Resonance. A B-minimum, magnetohydrodynamic stable configuration is used for trapping the plasma. The values of plasma density, temperature and confinement times are typically ne= 10¹¹−10¹³ cm⁻³, 01 eV<Te<10 k...

A K-band (18.5÷26.5 GHz) microwave interferometry/polarimetry setup, based on the Frequency-Modulated Continuous-Wave (FMCW) method, has been developed at INFN-LNS under the VESPRI project. The interferometer has been proven to provide reliable measurements of the plasma density even in the extreme unfavorable conditions λp Lp Lc, being λp, Lp and...

Electron Cyclotron Resonance Ion Sources are currently the most efficient ion sources among those used in facilities dedicated to nuclear physics. The need for a more flexible magnetic field and RF injection system suggested to design and develop a different type of plasma trap, named Flexible Plasma Trap (FPT). The magnetic field of FPT is generat...

Pinhole and CCD based quasi-optical x-ray imaging technique was applied to investigate the plasma of an electron cyclotron resonance ion source (ECRIS). Spectrally integrated and energy resolved images were taken from an axial perspective. The comparison of integrated images taken of argon plasma highlights the structural changes affected by some E...

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. Prom...

Optical Emission Spectroscopy (OES) represents a very reliable technique to carry out non-invasive measurements of plasma density and plasma temperature in the range of tens of eV. With respect to other diagnostics, it also can characterize the different populations of neutrals and ionized particles constituting the plasma. At INFN-LNS, OES techniq...

The fundamental aspect of coupling between microwave and plasma of the Electron Cyclotron Resonance Ion Source (ECRIS) and Microwave Discharge Ion Source (MDIS) is hereinafter treated together with "ad hoc" microwave-based plasma diagnostics, as a key element for the next progress and variations with respect to the classical ECR heating mechanism....

Gabor lenses are plasma traps that can be used for focus-ing an ion beam linearly without aberrations by the electric field of a confined electron cloud. They combine strong electrostatic focusing with the possibility of space charge compensation and provide an attractive alternative to conventional ion beam optics in a LEBT section. The focusing p...

Despite painting in Sicily presents only a few examples of famous masters, the island has been a point of transit and meeting of great painters. Among these, Caravaggio is definitely the most significant case. His painting technique and composition influenced over many decades a number of Baroque painters from all over Europe. Some of these old mas...

Electron cyclotron resonance ion sources (ECRIS) are widely used plasma based machines for the production of intense ion beams in science and industry. The performance of modern devices is limited by the presence of the density cut-off, above which electromagnetic (EM) waves sustaining the plasma are reflected. We hereby discuss the systematic data...

PANDORA, Plasmas for Astrophysics, Nuclear Decays Observation and Radiation for Archaeometry, is planned as a new facility based on a state-of-the-art plasma trap confining energetic plasma for performing interdisciplinary research in the fields of Nuclear Astrophysics, Astrophysics, Plasma Physics and Applications in Material Science and Archaeome...

PANDORA, Plasmas for Astrophysics, Nuclear Decays Observation and Radiation for Archaeometry, is planned as a new facility based on a state-of-the-art plasma trap confining energetic plasma for performing interdisciplinary research in the fields of Nuclear Astrophysics, Astrophysics, Plasma Physics and Applications in Material Science and Archaeome...

In linear (minimum-B) magneto-static traps dense and hot plasmas are heated by electromagnetic radiation in the GHz domain via the Electron Cyclotron Resonance (ECR). The values of plasma density, temperature and confinement times (neτi > 10 13 cm −3 s; Te > 10 keV) are similar to the ones of thermonuclear plasmas. The research in this field —devot...

An optimised RF power delivery in magnetoplasmas of ECR ion sources is crucial in order to provide a cost effective upgrade (plasma density and temperature increase and multiply charged ions production) of these machines without recurring to higher and higher magnetic fields, power level and pumping wave frequency. This can be done by following two...

This paper describes three-dimensional self-consistent numerical simulations of wave propagation in magnetoplasmas of Electron cyclotron resonance ion sources (ECRIS). Numerical results can give useful information on the distribution of the absorbed RF power and/or efficiency of RF heating, especially in the case of alternative schemes such as mode...

This article describes the design, the simulations, and the tests of a microwave launcher for alternative plasma-heating schemes in the Flexible Plasma Trap (FPT). A waveguide-phased array has been designed to tilt the wave injection angle: this will allow modal conversion to generate Electrostatic Bernstein Waves and then to obtain overdense plasm...

At the Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali del Sud (INFN-LNS) the commissioning of the high intensity Proton Source for the European Spallation Source (PS-ESS) started some weeks ago. Beam stability at high current intensity is one of the most important parameter for the first steps of the ongoing commissioning. Commissioning...

A Full Field X-ray Camera (FF-XRC) was developed for performing the simultaneous mapping of chemical elements with a high lateral resolution. The device is based on a conventional CCD detector coupled to a straight shaped polycapillary. Samples are illuminated at once with a broad primary beam that can consist of X-rays or charged particles in two...

The note presents the first plasma density measurements collected by a novel microwave interferometer in a compact Electron Cyclotron Resonance Ion Sources (ECRIS). The developed K-band (18.5 ÷ 26.5 GHz) microwave interferometry, based on the Frequency-Modulated Continuous-Wave method, has been able to discriminate the plasma signal from the spurio...

The versatile ion source is an off-resonance microwave discharge ion source which produces a slightly overdense plasma at 2.45 GHz of pumping wave frequency extracting more than 60 mA proton beams and 50 mA He+ beams. DAEδALUS and IsoDAR experiments require high intensities for H2 + beams to be accelerated by high power cyclotrons for neutrinos gen...

Electron cyclotron resonance ion sources (ECRIS) are the most efficient ion sources among those used in facilities for nuclear physics with stable and exotic beams, because of their ability to generate intense beams of medium charge state ions, or moderate intensities at high and very high state of charge (hundreds of eμA of U33+oXe34+). Their deve...

At Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS), the development of intense ion and proton sources has been supported by a great deal of work on the modelling of microwave generated plasmas for many years. First, a stationary version of the particle-in-cell code was developed for plasma modelling starting from an...

The Electron Cyclotron Resonance Ion Sources (ECRISs) development is strictly related to the availability of new diagnostic tools, as the existing ones are not adequate to such compact machines and to their plasma characteristics. Microwave interferometry is a non-invasive method for plasma diagnostics and represents the best candidate for plasma d...

A characterization of wave-to-plasma interaction in a quasi-flat magnetostatic field at 3.75 GHz has been carried out by using a small-wire movable RF antenna, connected to a spectrum analyzer. The coupling between electromagnetic and electrostatic waves leads to a characteristic spectral emission in low frequency range and around the pumping wave...

Different electron guns based on cold- or hot-cathode technologies have been developed since 2009 at INFN for operating within ECR plasma chambers as sources of auxiliary electrons, with the aim of boosting the source performances by means of a higher plasma lifetime and density. Their application to microwave discharge ion sources, where plasma is...

Imaging of the electron cyclotron resonance (ECR) plasmas by using CCD camera in combination with a pinhole is a non-destructive diagnostics method to record the strongly inhomogeneous spatial density distribution of the X-ray emitted by the plasma and by the chamber walls. This method can provide information on the location of the collisions betwe...

An experimental campaign aiming to investigate electron cyclotron resonance (ECR) plasma X-ray emission has been recently carried out at the ECRISs - Electron Cyclotron Resonance Ion Sources laboratory of Atomki based on a collaboration between the Debrecen and Catania ECR teams. In a first series, the X-ray spectroscopy was performed through silic...

One of the limiting factors for the full understanding of Electron Cyclotron Resonance Ion Sources (ECRISs) fundamental mechanisms consists of few types of diagnostic tools so far available for such compact machines. Microwave-to-plasma coupling optimisation, new methods of density overboost provided by plasma wave generation, and magnetostatic fie...

At Istituto Nazionale di Fisica Nucleare – Laboratorio Nazionale del Sud (INFN-LNS), a broad experience in the design, construction and commissioning of ECR and microwave ion sources is available. The AISHa ion source has been designed by taking into account the typical requirements of hospital-based facilities, where the minimization of the mean t...

This conceptual design report describes the technical facility for the IsoDAR electron-antineutrino source at KamLAND. The IsoDAR source will allow an impressive program of neutrino oscillation and electroweak physics to be performed at KamLAND. This report provides information on the physics case, the conceptual design for the subsystems, alternat...