Experimental characterization of gaseous ion beams produced with the advanced ion source for hadrontherapy (AISHa) at 18 GHz

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. Two sources have been realized: the first at INFN-LNS and the second at the Centro Nazionale di Adroterapia Oncologica (CNAO). The first one, fully commissioned at INFN-LNS, will be used as test-bench for development of new beams and several R&D activities are planned within the IONS experiment to increase plasma confinement and to refine techniques of non-invasive plasma diagnostics to correlate plasma and beam parameters. The second one recently produced the first beam and it will allow to increase the CNAO potential in the field of experimental and industrial research, with the long-term goal of introducing new ionic species into clinical practice such as helium, oxygen and later also iron and lithium, useful for bio-spatial research. In this work, the key peculiarities and the experimental results of the two Aisha ion sources will be presented.

Section: Resultsmentioning

confidence: 99%

“…Results of the AISHa commissioning at INFN-LNS together with further information on technological aspects can be found in Refs. [3,4]. Due to its peculiarity, a copy of AISHa ion source, hereinafter named AISHa-CNAO, has been chosen as the third ion source of the Centro Nazionale di Adroterapia Oncologica (CNAO) facility.…”

Section: Introductionmentioning

confidence: 99%

AISHa: an ECRIS for nuclear-physics, new clinical protocols and material experiments

Celona,

Leonardi,

Castro

et al. 2024

Application of Optical Emission Spectroscopy to Electron Cyclotron Resonance Ion Sources

Castro,

Reitano,

Leonardi

et al. 2024

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 hundreds of keV. Further improvements of ECRIS performances require a deeper and deeper understanding of the plasma heating mechanisms and ion generation by means of opportune plasma diagnostics. Amongst others, optical emission spectroscopy (OES) is the most remarkable for application in ECRIS: it is a non-invasive diagnostics able to operate also in high-voltage conditions and it requires small room for operation. OES has been already tested for plasma diagnostics in proton sources. This work presents the experimental set-up developed for the plasma diagnostics of the Advanced Ion Source for Hadrontherapy (AISHa), an ECRIS for medical applications, together with the strategy applied to relate plasma emission lines in the visible and near-infrared domain to plasma parameters for some ions of interest. Preliminary results and perspectives will be also discussed.

Design and preliminary tests of an Active Plasma Chamber for ECR Ion Sources

Odorici,

Castro,

Leonardi

et al. 2024

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 chamber. The purpose of this system is to reduce the ion losses induced by the anisotropic diffusion mechanism, to improve the plasma confinement and thus to increase the overall performance of the ion source. In fact, in ECRIS plasmas, electrons mostly diffuse along magnetic field lines while ions mostly leak across the same lines. In particular, the inner walls of the plasma chamber are covered with 30 tiles, each one polarized to a proper positive voltage. The tiles are made of Al-6082 and anodized except for the surface directly facing the plasma. The anodizing process makes each tile electrically insulated from the others and from the plasma chamber while preserving the correct operation of the cooling system. The tiles are wrapped by 2 half-cylinders made of Al-6082 acting as shells. Some tiles are equipped of a temperature sensor and machined to allow the wiring of the entire system. In this work the results of the preliminary tests of the thermal and electrical behaviour of the active chamber and the future perspectives are presented.