The purpose of this work is to search for the optimal design and arrangement of magnets to ensure the correct and uniform distribution of the magnetic field in the plasma chamber of the electron cyclotron resonance (ECR) source, using the DECRIS-5M source as an example. In this paper we investigate the influence of external magnetic fields created by solenoids in the area of a hexapole magnet from the point of view of demagnetization, as well as the selection of materials to minimize this effect. Also, we consider the influence of the material choice on the service life of magnets. Numerical simulations were carried out using the COMSOL Multiphysics software package. In addition, we have carried out magnetic field measurements of the DECRIS-5M source hexapole magnet. The results can be used to improve the characteristics of existing ion sources and for development of the new sources.

Processes of the secondary electron emission (SEE) from the walls are included into the Numerical Advanced Model of Electron Cyclotron Resonance Ion Sources (NAM-ECRIS). It is found that SEE strongly influences electron confinement time and ion production. With the modified model, we observe reactions of the source to changes in a gas flow into the source and in an injected microwave power. The source performance with scaling the hexapole magnetic field is investigated. The calculated tendencies are close to the experimental observations.

The three-dimensional particle-in-cell model NAM-ECRIS is used for investigation of how the DECRIS-PM Electron Cyclotron Resonance Ion Source is reacting to changes in the source magnetic configuration. The accent is made on changes in the magnetic field at the magnetic trap center, the minimum-B value. It is calculated that the optimal normalized value of the field is 0.8, close to the experimental observations. The reasons for existence of the optimum are discussed. It is observed that the electron energies are increasing with the increased minimum-B values due to enhanced confinement of the energetic electrons in the plasma. Bumps in energy spectra of the radially lost electrons are observed and explained to be due to nonadiabatic losses of electrons.

The three-dimensional NAM-ECRIS model is applied for studying the metal ion production in the DECRIS-PM Electron Cyclotron Resonance Ion Source. Experimentally measured extracted ion currents are accurately reproduced with the model. Parameters of the injection of metal vapors into the source are optimized. It is found that the axial injection of the highly directional fluxes allows increasing the extracted ion currents of the highly charged calcium ions by factor of 1.5. The reason for the gain in the currents is formation of internal barrier for the ions inside the plasma, which increase the ion extraction and production efficiency. Benefits of injecting the singly-charged calcium ions instead of atoms are discussed.

The Numerical Advanced Model of Electron Cyclotron Resonance Ion Source (NAM-ECRIS) is applied for studies of the physical processes in the source.Solutions of separately operating electron and ion modules of NAM-ECRIS are matched in iterative way such as to obtain the spatial distributions of the plasma density and of the plasma potential.Results reveal the complicated profiles with the maximized plasma density close to the ECR surface and on the source axis.The ion-trapping potential dips are calculated to be on the level of ~(0.01-0.05)V being located at the plasma density maxima.The highly charged ions are also localized close to the ECR surface.The biased electrode effect is due to an "electron string" along the source axis formed by reflection of electrons from the biased electrode and the extraction aperture.The string makes profiles of the highly charged ions more peaked on the source axis, thus increasing the extracted ion currents.

This article describes experiments for producing highly intense metal ion beams at the ECR source of the DC-60 cyclotron using the evaporation of organometallic compounds by the MIVOC method. As a result of the works, beams of nickel, cobalt, chromium, and silicon ions are obtained. The optimization of modes of acceleration for the ion beams to an energy of 1.75 MeV/n is carried out.

The mass, energy and angular distributions of binary fragments formed in the reactions 64Ni + 238U, 58Fe + 244Pu, 52Cr + 248Cm, 54Cr + 248Cm at energies near the Coulomb barrier have been measured. The analysis of energy distributions of the symmetric fragments with mass numbers $${{{{A}_{{{\text{CN}}}}}} \mathord{\left/ {\vphantom {{{{A}_{{{\text{CN}}}}}} 2}} \right. \kern-0em} 2} \pm 20$$ formed in these reactions have been applied to separate compound nucleus fission and quasi-fission. The estimated fusion probability for the reactions Cr, Fe, and Ni ions with actinide targets shows an exponential dependence on the mean fissility parameter of the system and shows also that reaction with Cr ions is more favorable for production of the super heavy element with Z = 120.

Three-dimensional numerical model is developed and applied for studies of physical processes in Electron Cyclotron Resonance Ion Source. The model includes separate modules that simulate the electron and ion dynamics in the source plasma in an iterative way. The electron heating by microwaves is simulated by using results of modelling the microwave propagation in the plasma by the COMSOL Multiphysics software. Extracted ion currents and other parameters of the source are obtained for different gas flows into the source. It is observed that the currents are strongly influenced by ion transport in transversal direction induced by the plasma potential gradients. Impact of some special techniques on the source performance is investigated. Magnetic field scaling is shown to reduce the ion losses during their movement toward the extraction aperture, as well as use of the aluminum chamber walls and mixing of the working gas with helium.

The results of experiments on the production of intense beams of heavy lithium, magnesium, phosphorus, and calcium ions with a microevaporator are reported. The first beams of 7Li, 24Mg, 31P, and 40Ca ions were produced in these experiments conducted in 2017–2018 at the DC-60 cyclotron. The modes of acceleration of these ions to an energy of 1.75 Mev/nucleon were also optimized.

In 2017-2018, research program of the DC-60 cyclotron (Astana Branch of the Institute of Nuclear Physics, Kazakhstan) requests acceleration of intense ion beams of solid elements. Beams of B and Fe ions are produced in ECR ion source by using the volatile compounds, while ions of Li, Mg, P and Ca are produced by evaporation from an oven. Beams of Fe-56(10+), Li-7(1+), Mg-24(4+), P-31(5+), Ca-40(7+), and B-11(2+) ions were accelerated up to energies of 1.32-1.75 MeV/u.

Charge-breeding processes in Electron Cyclotron Resonance Ion Sources are numerically simulated by using the target helium plasma parameters obtained with NAM-ECRIS code. Breeding efficiency is obtained as a function of 1+ ion injection energy for some alkali ion beams. Time dependencies of extracted ions are calculated; typical times for reaching saturation in currents are in the range of few tens of milliseconds. Role of charge-exchange processes in breeding of ions is discussed. Recycling of ions on the source walls is shown to be important.

Ion extraction from DECRIS-PM source is simulated by using initial distributions of ions at the extraction aperture obtained with NAM-ECRIS code. Three-dimensional calculations of plasma emissive surface are done and ions are traced in the extraction region. The ion beam profiles show strong aberrations due to shape of plasma meniscus; hollow beam features are reproduced, as well as changes in profiles for different focusing conditions.

Free parameters of Numerical Advanced Model of ECRIS (NAM-ECRIS) are selected such as to reproduce the experimental charge-state-distribution of the extracted argon ions for the DECRIS-PM source tuned to produce the maximized Ar8+ currents. Using these fixed parameters, we calculate the extracted currents for Kr, Xe and Bi ions in mix with oxygen, for Ca in mix with helium, and for pure O and He plasmas. Comparison is made with the experimental data, good correspondence is observed.

The paper presents the results of investigation of defect formation in AlN ceramics under Fe+7 ion irradiation with a fluence from 1 x 10(11) to 1 x 10(14) ion cm(-2) . The change in the main crystallographic characteristics, the decrease in the magnitude of Griffiths criterion, and the increase in the average voltage as a result of irradiation are caused by the appearance of additional defects in the structure and their further evolution leading to a change in the degree of crystallinity. For samples irradiated with Fe+7 ions to a dose of 1 x 10(11) ion cm(-2) , the formation of pyramidal hillocks is observed on the surface, whose average height is 17-20 nm. An increase in the irradiation dose leads to an increase in chillocks size and their density. At the same time, at large irradiation doses, the formation of conglomerates of chyllocks and grooves on the samples surface is observed. The change in surface morphology, the formation of chyllocks on the ceramic surface, and the dependence of the change in crystallographic characteristics during irradiation make it possible to unambiguously associate the formation of radiation defects in the structure of the ceramic with energy losses in elastic and inelastic interactions of iron ions with lattice atoms.

Accelerated beams of metal ions are required for a series of scientific and technical tasks in the field of radiation physics of a solid state, for example, the only method for rapid assessments of the radiation damage investigation, the developed structural materials of nuclear technology is ion irradiation. The standard methods for production ion beams at ECR-sources from gas mixtures cannot fully meet the requirements of the experiment. To increase the spectrum of accelerated ions at the cyclotron DC-60 is working on developing methods of heating the solid substances to produce multiply charged ion beams of metals into an ECR ion source DECRIS-3. The article is dedicated to description of methods of production ion beams of metals in two ways: the direct injection of a substance into plasma and a method of heating the crucible with a working substance by micro-furnace. As a result of the work carried out on the DC-60 cyclotron, beams of lithium ions 6,7Li, 24Mg magnesium, 31P phosphorus and 40Са calcium were produced for the first time. Using these methods was produced beams of lithium ions 7Li1+ metal consumption of 1.1 mg/hour and derived a ion beam current of 500 µA, magnesium 24Mg4+ with the consumption of the substance 2.1 mg/hour and intensity of 81 µA, phosphorus consumption of substances 1.7 mg/hour at the beam current 31P5+ 60 µA and calcium 40Ca5+ with the consumption of a substance of 0.7 mg/hour when the beam current is 140 µA.

This paper presents the design of the DECRIS-PM ECR ion source developed for the DC-280 cyclotron under construction at FLNR JINR. The results of the ion-source testing are presented. Highintensity beams for gaseous (900 μA of Ar8+, 550 μA of Ar9+, 160 μA of Kr15+, etc.) and solid targets (450 μA of Mg5+, 220 μA of Ca9+, 90 μA of Ti9+, etc.) are produced during the testing.

Super-heavy-element factory is under development at the Flerov Laboratory of-Nuclear Reactions, JINR, Dubna. The factory will include DC-280 cyclotron, which will be equipped with two 100 kV high voltage platforms. A high charge state all-permanent magnet 14 GHz ECRIS - DECRIS-PM has been designed and fabricated to provide intense multiple charge state ion beams. The request for the source is a production of medium mass ions (A/q=4 divided by 7) such as Ca-48(8+). The conceptual design of DECRIS-PM is presented. During the first tests, the source shows a good enough H performance for the production of medium charge state ions (such as 900 e mu A Ar8+, 550 e mu A Ar9+, 200 e mu Ar11+, A 160 e mu A Kr-15+, etc.).