High frequency acceleration system of the DC-280 cyclotron

The radio-frequency (RF) accelerating system designed at the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research (FLNR JINR), for the DC-280 cyclotron is described. The cyclotron is intended to increase the capabilities and efficiency of experiments on the synthesis of superheavy elements and investigate their nuclear-physical and chemical properties. The DC-280 isochronous heavyion cyclotron will produce an accelerated beam of ions in the range from neon to uranium. The results of the preliminary and 3D numerical calculations of the main cavity of this system are reported. The preliminary calculations by the Coaxresonator software have allowed the geometry of the main cavity to be chosen. 3D numerical simulation has completely confirmed the correctness of the preliminary calculations. For example, the difference in frequency between the preliminary and 3D numerical calculations is no larger than 1%. The electric-field component maps obtained from the simulations are used to calculate the beam dynamics in the cyclotron.     

Proposed design of axial injection system for the DC-280 cyclotron

The design of the high-voltage axial injection system for the DC-280 cyclotron that is being constructed at the Flerov Laboratory of Nuclear Reactions (FLNR) at the Joint Institute for Nuclear Research (JINR) is presented. The injection system will make it possible to efficiently inject ions of elements ranging from helium to uranium with the ratios of their atomic mass to the charge varying from 4 to 7.5.     

Start-Up of the DC-280 Cyclotron,the Basic Facility of the Factory of Superheavy Elements of the Laboratory of Nuclear Reactions at the Joint Institute for Nuclear Research

Physics of Particles and Nuclei Letters - The basic facility of the Factory of Superheavy Elements (SHE), the DC-280 cyclotron, in the Flerov Laboratory of Nuclear Reactions at the Joint Institute...     

Vacuum system of heavy ion cyclotron complex DC-60

The vacuum system of the heavy ion cyclotron complex DC-60 created at the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research for the interdisciplinary research complex (Astana, Kazakhstan) is described. The results of numerical simulation of transmission efficiency of accelerated ions in the course of recharging on residual gas, which determines the basic parameters of the designed vacuum system, are presented. As a result of successful implementation of the cyclotron complex DC-60 project, heavy ion beams were accelerated. The obtained parameters of the vacuum system agree completely with calculations, which were the basis of the project.     

3D simulation of the ion-beam transport in bending magnets and electrostatic deflectors

The equations and algorithms for calculating the charged-particle-beam dynamics in bending magnets and electrostatic deflectors, which are used in the ion-beam transport lines and spectrometers, are presented. Calculations of the electromagnetic field 3D maps are illustrated. The value of the electromagnetic-field nonlinearities and their effect on the particle dynamics are analyzed. The simulation of the ion dynamics in the axial injection beam line of the DC-280 cyclotron and GALS spectrometer created at the JINR Laboratory of Nuclear Reactions (FLNR) is described.     

Magnet design and beam dynamics in computed fields for the DC-350 cyclotron

The DC-350 is an isochronous cyclotron designed in the Flerov Laboratory of Nuclear Reaction (FLNR). It is intended for accelerating ions with a mass-to-charge ratio A/Z within an interval of 5–10 and with an energy of 3–12 MeV/u at the extraction radius. These ion beams will be used in nuclear and applied physics experiments. The paper describes the results of a 3D magnet simulation. The cyclotron magnet and IM90 analiziting-bend magnet of the axial injection channel are studied here. The influence of correction coils on the cyclotron magnet is calculated. All magnet fields were calculated by MERMAID 3D code [1]. The text was submitted by the authors in English.     

Correction of vertical displacement of extracted beam during commissioning tests of the DC-110 cyclotron

The specialized DC-110 heavy ion cyclotron has been developed and created at the Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research for the BETA research and production complex in Dubna (Russia), which allows producing intense accelerated Ar, Kr, and Xe ion beams with a fixed energy of 2.5 MeV/nucleon. Commissioning works on the cyclotron complex, during which the design parameters were obtained, were carried out at the end of 2012. During commissioning of the accelerator, vertical displacement of the beam was found at the final acceleration radii and during its extraction. It is shown that the main cause of this displacement was the occurrence of a radial component of the magnetic field in the median plane of the magnet caused by asymmetry of the magnetic circuit. Vertical beam displacement was corrected by creating asymmetry of the current in the main electromagnet winding of the DC-110 cyclotron.     

Positron emission isotope production cyclotron in DLNP JINR (Status Report)

A C10-cyclotron for radioisotope production is under construction at the Dzhelepov Laboratory of Nuclear Problem, Joint Institute for Nuclear Research (DLNP JINR). It is a compact isochronous cyclotron for accelerating H⁻ ions to the energy of about 10 MeV. The magnetic system, vacuum chamber and accelerating system is being built now. Results of the calculation and forming of the cyclotron magnetic field and the study of the beam dynamics from an ion source to an extraction system in calculated magnetic field are presented. The text was submitted by the authors in English.     

Heavy ion beam scanning system of DC-110 accelerator

A heavy ion acceleration complex for industrial applications based on the DC-110 cyclotron has been developed at the Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research. It is planned to irradiate polymer films with a width of up to 600 mm at this complex. This paper presents a design of a system for scanning heavy ion beam which offers uniform film irradiation at a beam energy of up to 2.5 MeV/nucleon. The general concept of the two-channel scanning system and the design of the main deflecting magnets are described.     

Development,creation, and startup of the DC-110 heavy ion cyclotron complex for industrial production of track membranes

The DC-110 heavy ion cyclotron for industrial production of track membranes has been developed and created at the Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research. The cyclotron is equipped with an electron cyclotron resonance ion source operating at a frequency of 18 GHz. The accelerator complex was put into operation in 2012 and ⁴⁰Ar⁶⁺, ⁸⁶Kr¹³⁺, and ¹³²Xe²⁰⁺ ion beams with a energy of 2.5 MeV/nucleon and intensity of 13, 14.5, and 10.5 μA, respectively, were produced. Irradiation of a polymer film was carried out on a specialized channel and track membranes with a high uniformity of pores were obtained. The DC-110 accelerator complex can produce up to 2 million square meters of track membranes per year.     

径向馈入和轴向馈入对感应加速腔性能的影响

 感应加速腔有径向馈入和轴向馈入两种常用的脉冲功率馈入方式。在理论上分析了不同功率馈入方式对感应加速腔输出电压平顶的影响,并对分析结果进行实验论证。实验采用1B2C结构,用相同的脉冲功率源馈入径向腔和轴向腔,测量此两种加速腔的电压波形。测得轴向腔±1％电压平顶时间为61 ns,径向腔±1％电压平顶时间为62 ns,两种腔都可满足±1%电压平顶大于60 ns的要求。此外对不同功率馈入方式导致的横向阻抗的变化进行了数值模拟,分别计算了采用这两种馈入方式的加速腔模型的横向阻抗,发现轴向加速腔的横向阻抗较小。     

Optimization of the magnetic field in the analyzing magnet of the axial injection beam line of the cyclotron DC-280

The optimization of the field distribution of the analyzing magnet installed in the axial injection beam line of the cyclotron DC-280 is carried out. This optimization is done on the basis of a three-dimensional calculation of the magnet field. The optimum value of the basic geometrical characteristics of the magnet influencing the form of the field distribution is found.     

Numerical simulation of ions acceleration and extraction in cyclotron DC-110

In Flerov’s Laboratory of Nuclear Reactions of JINR in the framework of project “Beta” a cyclotron complex for a wide range of applied research in nanotechnology (track membranes, surface modification, etc.) is created. The complex includes a dedicated heavy-ion cyclotron DC-110, which yields intense beams of accelerated ions Ar, Kr and Xe with a fixed energy of 2.5 MeV/A. The cyclotron is equipped with external injection on the base of ECR ion source, a spiral inflector and the system of ions extraction consisting of an electrostatic deflector and a passive magnetic channel. The results of calculations of the beam dynamics in measured magnetic field from the exit of spiral inflector to correcting magnet located outside the accelerator vacuum chamber are presented. It is shown that the design parameters of ion beams at the entrance of correcting magnet will be obtained using false channel, which is a copy of the passive channel, located on the opposite side of the magnetic system. Extraction efficiency of ions will reach 75%.     

DC-60 heavy ion cyclotron complex: The first beams and project parameters

The construction of the DC-60 Heavy Ion Cyclotron for the Interdisciplinary Scientific Research Complex (ISRC) in Astana started in early 2004. The cyclotron was manufactured and tested at the Flerov Laboratory of Nuclear Reactions (FLNR) in Dubna. The main units were delivered to Astana and assembled in the ISRC building in the summer of 2006. The cyclotron was turned on in September, 2006. The first heavy ion beams in the whole A/Z and energy ranges were accelerated and extracted in December, 2006. The complex, based on the DC-60 cyclotron, is intended for applied and fundamental research using accelerated heavy ion beams ranging from Carbon to Xenon with energies in the range of 0.34–1.77 MeV/nucleon, as well as for experiments on the channel of low energy ion beams, where the ion extraction voltage supplied by the ECR source reaches 25 kV. The energy variation of the accelerated ions is accomplished by changing the ion charge. The possibility of smoothly tuning the ion energy by ±30% of its nominal value can be seen by changing the cyclotron magnetic field. Within the framework of commissioning the DC-60 cyclotron, a number of experiments were carried out with accelerating charged particle beams in the main points of the working diagram

Production of Intense Ion Beams of Boron and Iron Using the MIVOC Method from ECR Ion Source on the DC-60 Cyclotron

This article describes experiments carried out in 2017–2018 at the DC-60 accelerator complex (Astana branch of the Institute of Nuclear Physics, Almaty, Kazakhstan) to develop methods for producing intense beams of multicharged iron and boron ions with the use of volatile organometallic compounds (Metal Ions from Volatile Compounds (MIVOC)). Beams of iron and boron ions were obtained for the first time on the DC-60 cyclotron, and the acceleration modes of ⁵⁶Fe¹⁰⁺ and 11B²⁺ ions were optimized to energies of 1.75 and 1.5 MeV/n, respectively.     

Stationary Temperature Distribution in a Rotating Ring-Shaped Target

For a rotating ring-shaped target irradiated by a heavy-ion beam, a differential equation for computing the stationary distribution of the temperature averaged over the cross section is derived. The ion-beam diameter is assumed to be equal to the ring width. Solving this equation allows one to obtain the stationary temperature distribution along the ring-shaped target depending on the ion-beam, target, and cooling-gas parameters. Predictions are obtained for the rotating target to be installed at the DC-280 cyclotron. For an existing rotating target irradiated by an ion beam, our predictions are compared with the measured temperature distribution.     

Magneto-optical rotation in cavity QED with Zeeman coherence

We investigate theoretically the magneto-optical rotation in cavity QED system with atomic Zeeman coherence, which is established via coherent population trapping. Owing to Zeeman coherence, the ultranarrow transmission spectrum less than 1 MHz with gain can be achieved with a flat-top Faraday rotation angle. By controlling the parameters appropriately, the input probe components within the flat-top regime rotate with almost the same angle, and transmit through the cavity perpendicularly to the other components outside the flat-top regime. The concepts discussed here provide an important tool for perfect ultranarrow Faraday optical filter and quantum information processing.     

Neutron yields upon irradiation of thick targets by ions with energies below 1.75 MeV/Nucleon

The yields of neutrons produced in thick LiF, Be, C, Al, Al₂O₃, and Cu targets irradiated by Li, C, and N ions with energies below 1.75 MeV/nucleon are measured on the DC-60 cyclotron at the Institute of Nuclear Physics, Astana Branch, Kazakhstan. The experimental angular distributions of the neutron yields from the targets are measured and an empirical equation to describe the distributions is proposed. The measured neutron yields are compared with the figures calculated by the LISE++ program. The measured and predicted neutron yields in the reactions coincide to within a factor of 2.     

Production of Intense Ion Beams of Nickel,Chromium, Silicon,and Cobalt at the DC-60 Cyclotron

Physics of Particles and Nuclei Letters - This article describes experiments for producing highly intense metal ion beams at the ECR source of the DC-60 cyclotron using the evaporation of...     

Secondary fusion reactions in the bombardment of light-element targets with low-energy heavy ions

Neutron emission was observed experimentally at the DC-60 cyclotron at the Institute of Nuclear Physics (Astana, Kazakhstan). The neutron yields were measured in the bombardment of light-element (Be, C, Al, Al₂O₃, and LiF) targets with heavy ions (Ar, Kr, and Xe) with energies below the Coulomb barrier. The angular distributions of neutrons from the targets were also measured. It was found that the observed neutrons were produced in secondary nuclear reactions between the resting target nuclei and recoil nuclei that acquire energy in the process of elastic scattering. The experimental results were compared with calculations based on the abovementioned secondary-reaction mechanism. The calculations allow one to estimate the yields of secondary reactions to within a coefficient of 2.