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The Ion-12SC is a sub-compact, 12.5 MeV proton super-conducting isochronous cyclotron for commercial medical isotope production recently developed at Ionetix Corporation. The machine features a patented cold steel and cryogen-free conduction cooling magnet, a low power internal cold-cathode PIG ion source, and an internal liquid target. It is designed to produce N-13 ammonia for dose on-demand cardiology applications but can also be used to produce F-18, Ga-68 and other medical isotopes widely used in Positron Emission Tomography (PET). The cyclotron is being installed and commissioned at several medical centers. During the initial machine operating periods, some issues appeared. In particular, imperfections in manufacturing and assembly of the magnet introduced unwanted low order magnetic harmonics that resulted in beam losses. This report presents results of analysis of the measured magnetic field and beam dynamics in the cyclotron that were initiated to solve the problem. The calculations led to a process for implementing compensating magnetic shims to improve the beam transmission. [ABSTRACT FROM AUTHOR]

The report contains a description of the conceptual design of a compact superconducting cyclotron, which can produce 20-MeV proton beam for isotopes production. The goal of the present project is to develop a machine that can be cost-effective, of small size and reliable in comparison with other particle accelerator systems aimed for producing proton beam of similar energy. Superconductivity is now a well established technology. Its application permits high magnetic field of the ultra-compact cyclotron that after careful system modeling and optimization can produce sufficiently good final beam parameters. The main parameters of the cyclotron, its design, and major stages of the development work are described in the report. [ABSTRACT FROM AUTHOR]

An AA6082 aluminum alloy reinforced with small additions of Al2O3 (0.2 wt.%) nanoparticles has been. The introduction of a powder master alloy in a metallic melt was carried out by simultaneous ultrasonic exposure and mechanical mixing. Furthermore, samples from the ingots of a reference alloy and a dispersion-strengthened alloy were subjected to a repeated severe plastic deformation (SPD) by using equal channel angular pressing at a temperature of 493 K. After SPD processing, an alloy structure was extensively worked. The presence of nanoparticles contributes to the formation of a more homogeneous and fine-grained structure in the composite after SPD treatment as compared to the reference alloy. We investigated the combined effect of dispersion hardening and SPD processing on the change of mechanical properties and plastic flow behavior of alloys. We found that the microhardness, yield strength, and ultimate tensile strength showed a sharp rise with a simultaneous increase in elongation before the fracture. Before and after the SPD treatment, the effect of increasing mechanical properties in the dispersion-hardened alloy was more pronounced than in the reference alloy. [ABSTRACT FROM AUTHOR]

The principles of formation of structure and properties of materials produced by self-propagating hightemperature synthesis (SHS) from the Al-Ti-B/B4C powder systems are identified. It is shown that the SHSmaterials produced from the Al-Ti-B powder systems consist of a TiAl intermetallic matrix with inclusions of titanium diboride particles. It is found out that an introduction of 1 wt.% of TiB2 particles into the melt of the AD35 aluminum alloy allows reducing the grain size from 620 to 220 μm and gives rise to an increase in the ultimate tensile strength of as-cast specimens from 100 to 145 MPa and in the plasticity from 7 to 9%. [ABSTRACT FROM AUTHOR]

Simulation results for mechanical mixing of aluminum melt using a mixing device are presented. It is found that an increase in the rotational velocity of the vortex device leads to intensive growth of turbulent diffusion in the liquid metal. Small vortices, although energetically weaker, can provide uniform mixing, creating regions of uniformity of several tens of microns. Experimental studies showed that use of a special mechanical mixing device enables injection of course titanium diboride particles and leads to significantly improved microstructure (reduction in average grain size from 900 μm to 400 μm) and mechanical properties of aluminum alloy A356. In particular, introduction of 0.2 wt.% titanium diboride particles using the vortex device leads to an increase in yield strength (from 15 MPa to 65 MPa) and ultimate tensile strength (from 140 MPa to 220 MPa) while preserving the ductility of the alloy (~4.5%) . [ABSTRACT FROM AUTHOR]

The authors consider and evaluate the physical parameters and regularities of the process of consolidation of Fe-Cu, Cu-Nb, Ag-Ni, Fe-Pb nanoparticles when creating composite materials by means of shock wave compaction. As a result of theoretical consideration of explosive compaction process, researchers established and discussed the physical process conditions, established a number of threshold pressure values corresponding to different target indicators of the state of the compact. The time of shock wave impact on powders for powder consolidation was estimated. [ABSTRACT FROM AUTHOR]

The development of a cyclotron magnetic system based on superconducting sector magnets is discussed. The cyclotron is conceived as a booster accelerator of a source of С ions with energy of 400MeV/nucleon for the purposes of hadron therapy. The results of preliminary investigations aimed at developing such a facility have been reported in our previous papers. In this paper, we consider various configurations of the booster's magnetic system for various field levels. We also analyze the effects of the positions and shapes of superconducting coils on the magnetic field and select the optimum configuration for the cyclotron's magnetic system. [ABSTRACT FROM AUTHOR]

Deagglomeration and wetting of submicron particles in a metal melt under ultrasonic exposure are considered based on the theory of acoustic cavitation and capillary phenomena. Basic dependences linking the exposure time with physicochemical properties of the particles and the melt, as well as with acoustic radiation characteristics, are found. The experimental and calculated times of ultrasonic treatment of the aluminum melt containing submicron aluminum oxide particles are compared, and a satisfactory agreement of results is found. [ABSTRACT FROM AUTHOR]

The development of the aerospace and automotive industries demands the development of aluminum alloys and composites reinforced with new nanoparticles. In this work, metal matrix composites (MMC) with an A356 aluminum alloy matrix reinforced with 0.2 wt.% and 1 wt.% of ScF nanoparticles were produced by ultrasonic dispersion of nanoparticles in the melt followed by casting in a metallic mold. Structure as well as physical and mechanical properties of the cast samples were examined using electron and optical microscopy, hardness and tensile testing. It is shown that nanoparticles clusters are formed during the solidification at grain boundaries and silicon inclusions. Increasing nanoparticles content significantly reduced the grain size in the MMC and increased the mechanical properties-ultimate tensile strength, elongation and hardness. The contribution of different strengthening mechanisms is discussed. It is suggested that the coefficient of thermal expansion mismatch between the nanoparticles ScF and the aluminum matrix is a dominant strengthening mechanism. [ABSTRACT FROM AUTHOR]

It is known that the use of external effects, such as acoustic fields (from ultrasonic to low-frequency range), help in breaking down agglomerates, improving particle wettability, providing uniform particle distribution in the melt volume, and reducing the grain size. The fragmentation of growing crystals, de-agglomeration of particles and their mixing in liquid metal under the influence of vibration (with frequencies of 10-100 Hz) are considered in this paper. The major advantage of such a technique in comparison with high-frequency methods (sonic, ultrasonic) is the capability of processing large melt volumes proportional to the wavelength. The mechanisms of the breaking down of particle agglomerates and the mixing of particles under conditions of cavitation and turbulence during the vibration treatment of the melt are considered. Expressions linking the threshold intensity and frequency with the amplitude necessary to activate mechanisms of turbulence and cavitation were obtained. The results of vibration treatment experiments for an aluminum alloy containing diamond nanoparticles are given. This treatment makes it possible to significantly reduce the grain size and to improve the casting homogeneity and thus improve the mechanical properties of the alloy. [ABSTRACT FROM AUTHOR]

Systems of beam injection from the Booster and fast beam extraction for injection into the collider will be developed in order for the Nuclotron to operate in the framework of the NICA accelerator complex. All systems are based on the Lambertson magnets. The shortened superconducting loop is used for compensating scattered fields in the circulating beam chamber. The finite weld resistance (on an order of several nΩ) results in gradual current storage in the loop, which influences the beam upon injection. To eliminate this effect, a heater for converting the loop into the normal conducting state in the pause between cycles is applied. [ABSTRACT FROM AUTHOR]

The process of introduction of submicron agglomerates and nanostructured particles into a poorly wetting liquid exposed to ultrasound is theoretically considered. The main dependences relating the exposure time to the physical and chemical properties of particles and liquid as well as to the characteristics of acoustic radiation are obtained. [ABSTRACT FROM AUTHOR]

The influence of introduction of particles of detonation-synthesized nanodiamonds into composites and aluminum-base light alloys on their physical and mechanical properties is analyzed. The data on microstructure and physical and mechanical properties of composites and cast aluminum alloys reinforced with diamond nanoparticles are presented. The introduction of nanoparticles is shown to result in a significant improvement of the material properties. [ABSTRACT FROM AUTHOR]

Metal matrix composites (MMC) based on aluminum and reinforced with nonmetallic particles are of great practical interest due to their potentially high physico-mechanical properties. In this work, Al-AlC composites were obtained by a hot-compacting method. Introduction of nanodiamonds produced by detonation to the Al powder in an amount of 10 wt.% led to the formation of ~15 wt.% of aluminum carbide during hot compacting. It was found that composite materials with the diamond content of 10 wt.% in the initial powder mix have an average microhardness of 1550 MPa, whilst the similarly compacted aluminum powder without reinforcing particles shows a hardness of 750 MPa. The mechanical properties of an Al-AlC MMC at elevated test temperatures exceeded those of commercial casting aluminum alloys such as A356. [ABSTRACT FROM AUTHOR]

Changes in structure, phase composition and crystal structure parameters are studied for materials of the ZrO-MgO system after cyclic thermal shock effects. Features are revealed for formation of ceramic structure and phase condition with implementation of internal stresses connected with a sharp change in temperature. Optimum compositions are established for refractory materials based on ZrO answering high specifications for thermal shock resistance and refractoriness. [ABSTRACT FROM AUTHOR]

The results obtained from investigations into the special features inherent in the mechanical characteristics (Hugoniot elastic limit and spall strength) observed under shock-wave loading of Al-AlO composite samples produced by an explosive powder compaction technique are presented. Embedding 10 wt.% of aluminum oxide in the aluminum matrix has been found to increase the Hugoniot elastic limit as opposed to the commercialgrade AD1(Al 1013) aluminum alloy. [ABSTRACT FROM AUTHOR]

The results obtained from investigations into the microstructure and physical-mechanical and electrical properties of cast aluminum-based alloys reinforced with nanodiamonds are presented. Addition of the diamond nanoparticles is shown to change the structural parameters and improve the mechanical properties of the materials. [ABSTRACT FROM AUTHOR]

The article focuses on the self propagating and high temperature synthesis of Aluminium (Al) and Titanium (Ti) borides. Topics discussed include properties of Al and Ti such as high melting temperature and thermal stability, exothermic reactions of Ti and Al interaction with boron and study on the problems associated with the synthesis of Al and Ti borides by combustion.

The scientific design of a 14-MeV H compact superconducting cyclotron for producing of the F and N isotopes has been developed. Main requirements to the facility as a medical accelerator are met in the design. In particular, the main requirement for the cyclotron was the smallest possible size due to the superconducting magnet. The calculations show that the proposed cyclotron allows extracted beam intensity over 500 μA. To increase system reliability and production rates, an external H ion source is applied. The choice of the cyclotron concept, design of the structure elements, calculation of the electromagnetic fields and beam dynamics from the ion source to the extraction system were performed. [ABSTRACT FROM AUTHOR]

Results of an x-ray phase analysis and investigations into the structure and mechanical properties of aluminum-base alloys produced by shock-wave compaction are presented. The method under study makes it possible to obtain samples with density approaching the theoretical value and improved mechanical characteristics. [ABSTRACT FROM AUTHOR]

The morphology and phase composition of nanocrystalline powders of aluminum and carbon in the form of cluster diamonds are investigated. It is found that the hot compaction of the C-Al powder mixture is accompanied by the formation of an AlC phase that has a highly disperse structure. The average crystallite size in hot-compacted materials is 40 nm for the metal matrix and 30 nm for aluminum. It is shown that as the carbon fraction in the initial powder mixture rises, the volume of the threshold space in hot-compacted materials increases. [ABSTRACT FROM AUTHOR]

Here we present results of the computer design of the structural elements of a compact cyclotron by the example of HITFiL cyclotron selected as the driving accelerator that is under construction at the Institute of Modern Physics (Lanzhou, China). In the article a complex approach to modeling of the compact cyclotron, including calculation of electromagnetic fields of the structural elements and beam dynamics calculations, is described. The existing design data on the axial injection, magnetic, acceleration and extraction systems of the cyclotron are used as a starting point in the simulation. Some of the upgrades of the cyclotron structural elements were proposed, which led to substantial improvement of the beam quality and transmission. [ABSTRACT FROM AUTHOR]

Results obtained from an x-ray phase analysis and mechanical tests on compression of hot-pressed Al-Al C composites with 5 or 10 wt.% C added to the initial powder mixture are presented. It is shown that the higher is the amount of aluminum carbide formed under hot pressing, the higher are the yield stress and the effective elastic modulus of the composite. [ABSTRACT FROM AUTHOR]

This paper describes the modeling and optimization of the parameters of the structural elements of the compact cyclotron. In particular, the optimization of the centering procedure by selection of the accelerated ion central trajectory and the corresponding inflector parameter is considered. [ABSTRACT FROM AUTHOR]