Abstract At GSI the CAPRICE ECRIS is in operation to deliver high charge state ion beams from gaseous and metallic elements to the accelerator facility. A test campaign has been carried out at the ...ECR test bench to fulfill the demand for higher intensity and stability of high charge state ions and for mixed ion beams. The ion beam stability has been monitored by an Optical Emission Spectrometer (OES), which has been already used to check the plasma and the temperature of the resistively heated oven during metal ion beam operation, particularly for Ca ion beams. During the test campaign, it was investigated that the OES can be used for monitoring the stability of ion beams from gaseous elements and mixed ion beams, and the main achieved results are reported. The ion beams extracted from the ECRIS have been simulated with a particle tracking code in order to study and improve the beam matching into the RFQ. The preliminary results of the study together with possible modifications of the extraction column are presented.
Abstract We present a numerical study of metals dynamics evaporated through resistively heated ovens in electron cyclotron resonance (ECR) plasma traps, used as metal ion beam injectors for ...accelerators and multi-disciplinary research in plasma physics. We use complementary numerical methods to perform calculations in the framework of the PANDORA trap. The diffusion and deposition of metal vapours at the plasma chamber’s surface are explored under molecular flow regime, with stationary and time-dependent particle fluid calculations via COMSOL Multiphysics®. The ionisation of vapours is then studied in the strongly energised ECR plasma. We have developed a Monte Carlo (MC) code to simulate the in-plasma metal ions’ dynamics, coupled to particle-in-cell simulations of the plasma physics in the trap. The presence of strongly inhomogeneous plasmas leads to charge-exchange and electron-impact ionisations of metals, in turn affecting the deposition rate/pattern of the metal on the walls of the trap. Results show how vapours dynamics depends both on evaporated metals and the plasma target. The 134 Cs, 176 Lu, and 48 Ca isotopes were investigated, the first two being radioisotopes interesting for the PANDORA project, and the third as one of the most required rare isotope by the nuclear physics community. We present an application of the study: MC computing the γ activity due to the deposited radioactive neutral nuclei during the measurement time, we quantitatively estimated the overall γ -detection system’s efficiency using GEANT4, including the poisoning γ -signal from the walls of the trap, relevant for the γ -tagging of short-lived nuclei’s decay rate in the PANDORA experiment. This work can give valuable support both to the evaporation technique and plasma source optimisation, for improving the metal ion beam production, avoiding huge deposit/waste of metals known to affect the long-term source stability, as well as for radio-safety aspects and reducing material waste in case of rare isotopes.
Uncertainty remains on the pathogenetic mechanisms, model of inheritance as well as genotype-phenotype correlation of FMF disease.
To investigate the impact of genetic factors on the FMF phenotype ...and the disease inheritance model.
A total of 107 FMF patients were enrolled. Patients were diagnosed clinically. All patients underwent genetic analysis of the FMF locus on 16p13.3.
9 distinct mutations were detected. Specifically, the 85.98% of patients showed a heterozygous genotype. The most common genotypes were p.Met680Ile/wt and p.Met694Val/wt. The most frequent clinical findings were fever, abdominal pain, joint pain, thoracic pain, and erysipelas-like erythema. Analysis of clinical data did not detect any significant difference in clinical phenotype among heterozygous, homozygous as well as compound homozygous subjects, further supporting the evidence that, contrary to the recessive autosomal inheritance, heterozygous patients fulfilled the criteria of clinical FMF. Moreover, subjects with p.Met694Val/wt and p.Met680Ile/wt genotype reported the most severe clinical phenotype. p.Ala744Ser/wt, p.Glu148Gln/Met680Ile, p.Met680Ile/Met680Ile, p.Met680Ile/Met694Val, p.Pro369Ser/wt, p.Met694Ile/wt, p.Glu148Gln/Glu148Gln, p.Lys695Arg/wt resulted in 100% pathogenicity.
The existence of a “non classic” autosomal recessive inheritance as well as of an “atypical” dominant autosomal inheritance with incomplete penetrance and variable expressivity cannot be excluded in FMF.
•Familial Mediterranean fever (FMF) is the most common Mendelian autoinflammatory disease.•Uncertainty remains on the model of inheritance and genotype-phenotype correlation of FMF.•Dominant autosomal inheritance with incomplete penetrance and variable expressivity in FMF.•We speculated on the real disease genetic testing usefulness.
Abstract Metals can be injected into electron cyclotron resonance ion sources (ECRIS) via different techniques, among which resistive ovens are used to vaporize neutral materials, later captured by ...the energetic plasma that will step-wise ionize them, hence giving multiply charged ion beams for accelerators. Recently, PANDORA, a novel ECR plasma trap, has been conceived to perform interdisciplinary research spanning from nuclear physics to astrophysics, where in-plasma high charge states of metallic species are demanded. However, a full knowledge on the vaporization method and on the coupling of neutral atoms with plasma and its overall dynamics is still not available. Simulations, hence, are of fundamental relevance to improve the overall efficiency, reduce consumption of rare expensive isotopes, and to improve the ion source performance. We present a numerical study about metallic species suitable for oven injection in ECRIS, focusing on metals diffusion, transport, and wall deposition under molecular flow regime. We studied the metal dynamics with and without plasma. Results underline the plasma role on a space-dependent conversion yield, reflecting the strongly inhomogeneous ECR plasma. The plasma and its parameters have been modelled using an established self-consistent particle-in-cell model. The numerical tool is conceived for the PANDORA plasma trap but can be extended to other ECR plasmas and traps. As test cases we studied the 134 Cs and 48 Ca radioisotopes, as metals of interest for the modern nuclear physics. A focus is given on the β -decaying 134 Cs, as an application case for PANDORA, providing quantitative estimates of the γ-detection signal-poisoning effect by neutral metals deposition at the chamber wall.
Abstract
Resistive oven technique is used to inject vapours of metallic species in electron cyclotron resonance (ECR) plasma traps, where plasma provides step-wise ionization of neutral metals, ...producing charged ion beams for accelerators. We present a numerical survey of metallic species suitable for oven injection in ECR ion sources, studying neutrals diffusion and deposition under molecular flow regime. These aspects depend on geometry of the evaporation inlet, thermodynamics, and plasma parameters, which strongly impact on ionization and charge-exchange rate, thus on the fraction of reacting neutrals. We considered diffusion of metals with and without plasma. The plasma and its parameters have been modelled considering an established self-consistent particle-in-cell model. Numerical predictions might be relevant to reduce the metal consumption, to increase the overall efficiency, and to improve the plasma ion source performances. As test case, we studied the
134
Cs isotope, as one of the alkali metals of interest for the modern nuclear physics.
Abstract
In order to increase intensities and charge states of available ion species, a new room-temperature ECR Ion Source (ECRIS) operating at 18 GHz is currently under development at GSI. The new ...ECRIS is based on a Heavy Ion Ion Source Injector (HIISI), developed at the Department of Physics, University of Jyvüskyla (JYFL), and features three normal conducting coils and a permanent magnet hexapole for plasma confinement. The latter has to be installed inside a refrigerated hexapole chamber, allowing to achieve the required radial confining field and avoiding demagnetization of permanent magnets. Computer simulations are carried out with Opera software package for two Halbach hexapole arrangements and the resulting three-dimensional magnetic fields are compared. The demagnetization of permanent magnets due to the superposition of fields generated by the coils and the hexapole is also simulated for both arrangements.
Abstract 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 Accelerator Based Sciences) research infrastructures. The EURO-LABS is a four-year project funded by the Horizon Europe program of the European Commission for years 2022 - 2026. In the ERIBS collaboration the best expertise, know-how and practices of the ECRIS community will be exploited and transferred between the partners to take full advantage of the European ion source infrastructure. The aim is to extend the beam variety available for the European user community by developing beam production methods and techniques. This development includes further improvement of technologies related to high temperature ovens, axial sputtering and MIVOC method for all the participating laboratories. We will also aim to improve both short- and long-term plasma and beam stability, as well as methods for online monitoring of these conditions. This can be realized, for example, by optical emission spectroscopy, identifying kinetic plasma instabilities by means of hard x-ray detection and using online beam current monitoring systems. An example of the recent developments is the new collaboration proposed by the CNRS-IPHC team to synthesize enriched MIVOC compounds for the other ERIBS partners. For example, the team successfully prepared an enriched chromocene compounds, which were needed to produce intensive 54 Cr and 50 Cr beams for the JYFL and GANIL nuclear physics programs, respectively.
We compare the output of a high-resolution regional climate model (RCM) with 40 yr of weather data from 64 weather stations from the Italian National Air Force network. Climatic zones were identified ...using the Ward's method for cluster analysis for minimum and maximum temperature and rainfall. The model is able to generate realistic spatial patterns of the observed clusters, although with different skills depending on the considered variable. The closest match between model and observations is for daily minimum temperature. The maximum temperature shows an unrealistic summer peak for most of the clusters. The model also consistently produces too many strong warm events during summer, and shows a tendency to overestimate total rainfall, especially during spring and early summer. The frequency and intensity of extreme events are well captured only for minimum temperature for Alpine and mountain weather stations. In spite of these biases and mismatches, this study shows, by means of a direct comparison with weather station data, that even in an area of complex orography and land−sea contrast such as the Mediterranean area, RCMs are able to produce realistic climate patterns at spatial scales that the global driver cannot capture.
The measurements of x-ray bremsstrahlung spectra from electron cyclotron resonance (ECR) ion sources have shown in the past that the electrons may gain energy inside the plasma up to about 2 MeV. In ...2000 a series of experiments carried out at INFN-LNS with the SERSE source operating at 28 GHz provided evidence that high energy x-rays were produced, as the heat load on the cryostat was increased because of their dissipation on the cold mass. This result shows that the knowledge of ECR heating is incomplete, because the so-called adiabatic limit was exceeded by many electrons. More recently similar measurements were carried out at IMP, Lanzhou, with the SECRAL source, and with the VENUS (Versatile ECR for Nuclear Science) source at LBNL, operating at 28 GHz with a better plasma confinement than SERSE. It will be shown hereinafter that the generation of energetic electrons (up to 2 MeV) is mainly related to the magnetic field gradient; also the charge state distribution depends on the magnetic structure, and its variation can be studied in terms of regime transition from gentle to strong gradients. For this purpose, numerical simulations of the ECR heating based on a single particle approach have been used.
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