The Krion-6T Electron string ion source (ESIS) is the main device for heavy ion production for the Nuclotron-based Ion Collider fAcility (NICA) injector. The ion source was created at Laboratory of High Energy Physics, Joint Institute for Nuclear Research (JINR), and it has been used several times for heavy ion beams production at the Nuclotron injector. Recently, Ar13+ and Xe28+ ion beams produced with the Krion-6T ESIS have been accelerated in the Heavy Ion Linac (HILAC) Booster (booster synchrotron) Nuclotron session in framework of the 4th stage of commissioning of the NICA complex. Further development of the ion source requires the production of Xe32+–34+ and Bi35+–37+ ion beams and their multiple injection through RFQ-HILAC into Booster and Nuclotron. Currently, Xe28+ ion beams have been produced in the Krion-6T ESIS in a multipulse mode (up to ten pulses per series), extracted from the ion source with an interval of 100 ms between pulses. In the near future, the accumulation and electronic cooling of this series of the ion pulses in the Booster synchrotron is proposed. This should make it possible to increase the intensity of the ion beam in the Booster by an order of magnitude. The time of the acceleration cycle is the NICA complex is assumed to be 4–6 s. An approved technology for the injection of bismuth atoms into the Krion-6T ion source is reported; the first stand results of Bi37+ ion beams production are briefly presented and discussed.

The NICA accelerator complex intended for studying baryonic matter and research in spin physics is currently at the stage of construction and mounting at the JINR. The NICA injection complex was designed to produce heavy ions with an energy of 1–3.9 GeV/u. The injection complex consists of two new accelerators: Heavy Ion Linear Accelerator, HILAC, and the superconducting synchrotron, Booster, and the modernized superconducting synchrotron, Nuclotron. The injection facility provides heavy ion beams for the NICA collider and the fix target experiments. The results of the fourth Booster-Nuclotron beam run for fix target experiments on the BM@N setup are discussed. The completion of the facility equipment construction and mounting are also presented along with the plans of first collider runs.

Solving the optimization problem for the characteristics of the thermal source of a cryogenic cella multilayer cylindrical sandwich-type configuration designed for a pulsed dosed injection of working substance into the ionization chamber of the source of multiply charged ionsis considered. To solve the optimization problem, we have developed the MPI+OpenMP hybrid parallel calculation algorithm based on the brute force method and software to search for the maximum of the integral of proportionality to the volume of gas evaporated from the cell surface. Solving the optimization problem for a specific cell configuration with the use of the supercomputer Govorun has demonstrated a ten- to hundredfold acceleration of the calculations.

Electron string ion source (ESIS) KRION-6T is one of the main parts of the NICA injection complex [1]. During the work on creation of a new ion source for the NICA/MPD project the new ion motion control system was developed, produced and successfully put into operation. Modules development process and operation results are described.

*e-mail: dorofeevgl@mail.ru Abstract The development of high-temperature superconducting (HTS) materials, especially HTS tapes of the second generation (2G HTS tapes) give us new opportunities to use superconductivity in high-energy physics devices and, in particular, in charged particle accelerators. The influence of the unclosed magnetic shield made of 2G HTS tape on the dynamics of a charged particles beam is studied in this paper. Within the framework of the simplest model of the interaction of the magnetic field of a charged particles beam with a superconducting shield, estimates of this influence are made. The superconducting shield shifts of a charged particles beam to its axis. In particular, the beam of ions 197Au79+ energy of 4 GeV per nucleon and a current of 5 A passing at a distance of 5 10 mm from the axis of the superconducting screen with a radius of 50 mm and a length of 5 meter is shifted to the axis of the screen at a speed of about 130 m/sec. That is, the beam itself can be centered for a lot less than 1 second. The possibilities of using an unclosed superconducting shield to compress a charged particles beam are discussed, as well as the possibilities of controlling the shield.

A singly charged ion source (SCIS) has been designed using a newly developed three-dimensional particle-in-cell (PIC) code. The SCIS is to be used in an isotope separation on-line (ISOL) system that provides 11C ions for heavy-ion cancer therapy with simultaneous verification of the dose distribution using positron emission tomography. The SCIS uses low-energy electron beams to produce singly charged carbon ions efficiently and maintain a high vacuum in the ISOL system. Because the SCIS has to realize a production efficiency of 1% if its carbon ions are to be used in the ISOL system, a suitable design for the SCIS was investigated by using the developed PIC code to study the beam trajectories of the electrons and extracted ions. The simulation results show that hollow electron beams are produced in the designed SCIS resulting in a high effective electron current. The results also predict that the designed SCIS would realize ion-production efficiencies (IPEs) of ε SCIS ≃ 6.7% for C O 2 + production from CO2 gas and ε SCIS ≃ 0.1% for C+ production from CH4 gas. Moreover, to examine the validity of the developed code and confirm that the SCIS was able to be designed appropriately, the space-charge-limited current of the electron gun and the total IPE obtained by adding the IPEs of each ion were compared between the experiment and the simulation.

Programs for the pre-processing of photographs of beam images on the mask based on Wolfram Mathematica and Origin software are described. Angles of rotation around the axis and in the vertical plane are taken into account in the generation of the file with image coordinates. Results of the emittance calculation by the Pep_emit program written in Visual Basic using the generated file in the test mode are presented.

The work describes the maximization problem regarding the heating of an area on the surface of a thin plate within a given temperature range. The solution of the problem is applied to ion injectors. The given temperature range corresponds to the required pressure of a saturated gas comprising evaporated atoms of the plate material. In order to find the solution, a one-parameter optimization problem was formulated and implemented leading to the optimization of the plate specific geometry. It was shown that a heated area can be increased up to 23.5% in comparison with a regular rectangle form of a given plate configuration.

The type of the Electron String Ion Sources (ESIS) is considered to be the appropriate one to produce pulsed C(4+) and C(6+) ion beams for cancer therapy accelerators. In fact, the new test ESIS Krion-6T already now provides more than 10(10) C(4+) ions per pulse and about 5 × 10(9) C(6+) ions per pulse. Such ion sources could be suitable to apply at synchrotrons. It has also been found that Krion-6T can provide more than 10(11) C(6+) ions per second at the 100 Hz repetition rate, and the repetition rate can be increased at the same or larger ion output per second. This makes ESIS applicable at cyclotrons as well. ESIS can be also a suitable type of ion source to produce the (11)C radioactive ion beams. A specialized cryogenic cell was experimentally tested at the Krion-2M ESIS for pulse injection of gaseous species into the electron string. It has been shown in experiments with stable methane that the total conversion efficiency of methane molecules to C(4+) ions reached 5%÷10%. For cancer therapy with simultaneous irradiation and precise dose control (positron emission tomography) by means of (11)C, transporting to the tumor with the primary accelerated (11)C(4+) beam, this efficiency is preliminarily considered to be large enough to produce the (11)C(4+) beam from radioactive methane and to inject this beam into synchrotrons.

A (11)C molecular production/separation system (CMPS) has been developed as part of an isotope separation on line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive (11)C ion beams. In the ISOL system, (11)CH4 molecules will be produced by proton irradiation and separated from residual air impurities and impurities produced during the irradiation. The CMPS includes two cryogenic traps to separate specific molecules selectively from impurities by using vapor pressure differences among the molecular species. To investigate the fundamental performance of the CMPS, we performed separation experiments with non-radioactive (12)CH4 gases, which can simulate the chemical characteristics of (11)CH4 gases. We investigated the separation of CH4 molecules from impurities, which will be present as residual gases and are expected to be difficult to separate because the vapor pressure of air molecules is close to that of CH4. We determined the collection/separation efficiencies of the CMPS for various amounts of air impurities and found desirable operating conditions for the CMPS to be used as a molecular separation device in our ISOL system.

An assembly for a commercial Ga(+) liquid metal ion source in combination with an ion transportation and focusing system, a pulse high-voltage quadrupole deflector, and a beam diagnostics system has been constructed in the framework of the iThemba LABS (Cape Town, South Africa)-JINR (Dubna, Russia) collaboration. First, results on Ga(+) ion beam commissioning will be presented. Outlook of further experiments for measurements of charge breeding efficiency in the electron string ion source with the use of external injection of Ga(+) and Au(+) ion beams will be reported as well.

A high-voltage platform that has been developed for the KRION ion source is described. The platform design concept is explained. The calculations that have been performed of the influence of the design and materials on the source magnetic field make it possible to define a range of materials suitable for manufacturing the platform. The major components of the high-voltage platform, such as a high-voltage power supplier, and decoupling insulators of the high-voltage power source, and the main and supplementary platforms, are chosen and described. It is determined that, to exclude electric breakdowns and corona discharges, one should use an electrically shielded channel with a cryocooler and power supplies for the KRION-source coupling cables.

The project of a superconducting medical synchrotron for carbon therapy in the ion energy range from 140 to 400 MeV/n is discussed in this paper. This project is aimed at developing and building a medical synchrotron on the basis of superconducting technologies at JINR under the construction of the Nuclotron accelerator complex. A linear accelerator with alternating phase focusing is proposed for injecting carbon ion into the synchrotron, while it is planned to use a superconducting gantry weighing about 150 t for delivering radiation treatment to patients from all directions.

The most recent experimental information on electron string phenomenon, such as two step transition to electron string state, stability of e-strings in condition of electron energy recuperation, are described. The new technology developments of electron string ion sources (ESIS) include pulse injection of gaseous species in e-string and its efficient conversion to ion beams, slow ion extraction, ion-ion cooling of heavy ions with CH(4) coolant, and a progress in the construction of the new Joint Institute for Nuclear Research ESIS with 6 T solenoid are briefly considered.

Electron String Ion Source (ESIS) (JINR) is the first and now only ion source of such type in the world. ESIS is a sophisticated modification of Electron Beam Ion Source (EBIS) working in a reflex mode of operation under very specific conditions. Using the results of the research and the technology development the following main results were achieved in JINR with Krion-2 ESIS during recent years: Au 54+

This paper reports on the study of some solutions for a system of coupled nonlinear wave equations of a hyperbolic type, effectively dependent on one spatial (radial) variable and one time variable. This system of equations, which is a coupled system of the Yang-Mills equations with a scalar field, i.e., dilaton, belongs to the so-called class of supercritical systems, for which there exist solutions that inevitably lead to the formation of singularities at a point or even a whole region during a finite period of time at smooth initial distributions with finite energy. This system of equations has regular stationary solutions with finite energy. All such stationary solutions are unstable and can be parametrized by the number N, which is the number of their unstable eigenmodes in linear approximation, and N = 1, 2, 3, …, ∞. The self-consistent problem of the decay of such stationary solutions with N = 1, 2, 3, 4 on the independent excitation of their unstable eigenmodes was solved numerically in nonlinear regime. The corresponding initial-boundary problem was investigated numerically by means of an adaptive computation scheme based on a conservative finite-differential scheme with energy conservation. It has been found that for each considered stationary solution only the perturbation of its basic unstable eigenmode leads to the formation of the singularity/scattering alternative, the governing parameter in the choice of the alternative being the sign of the major unstable eigenmode. It is shown that the independent perturbation of all higher unstable eigenmodes necessarily leads to the formation of a singularity. It is also found that the nonlinear waves formed with the decay of the basic N = 1 solution on the perturbation of its single unstable mode may expose some properties peculiar to solitons.

Nuclear emulsion was exposed to xenon nuclei accelerated at the JINR Nuclotron. Visual and automated scanning of the extracted beam profile was performed using the exposed emulsion film.

The results of 2.5D particle-in-cell simulation of a coaxial electron trap with an internal anode are reported. It is found that, when the circulating current reaches the value of the ultimate vacuum current, first a virtual cathode arises in the trap and then the beam compresses (distributed virtual cathode). The transient preceding the compressed state exhibits complicated nonlinear dynamics, when compressed regions alternate with regions that are in a two-flow state (phase-space bubbles or phase-space holes). Physically, phase-space holes are similar to the well-known Bernstein-Greene-Kruskal plasma structures. Three types of phase-space holes with different dynamics (oscillating holes, flying holes, and chaotic holes) are revealed. Consideration of phase-space holes as quasi-particles makes it possible to find several channels of their interaction in pair collisions. The feasibility of the coaxial trap as a source of highly charged ions is analyzed. Although the compressed beam mode provides a larger amount of accumulated electrons compared with the conventional two-flow mode, the mean kinetic energy in the presence of a virtual cathode turns out to be much lower. A way of elevating the mean kinetic energy is suggested that consists in increasing the limit vacuum current in the axial configuration with an internal electrode.