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The article presents the results of studying the transfer of heat and particles in the Globus-M2 spherical tokamak in discharges with neutral injection at the current ramp up. An atomic beam was injected into the tokamak plasma at a fixed toroidal magnetic field of 0.7 T. The plasma current on the plateau was varied in the range 0.2–0.3 MA. Based on the electron temperature and concentration spatial distributions measured by the Thomson scattering method, the transport of heat and particles in plasma was simulated using the ASTRA code. The energy confinement time of the plasma was determined, as well as estimates of the coefficients of thermal diffusivity and diffusion was made.

Two algorithms for calculating the neutron yield of the Globus-M2 tokamak are considered for the case of anisotropic ion velocity distribution functions. Such calculations are necessary for estimating the neutron flux produced as a result of the interaction between fast particles (deuterons) arising from the injection of a high-energy atomic beam. The first algorithm comprises the calculation of the six-dimensional integral in the velocity space, and the second uses the expansion of the ion distribution function in Legendre polynomials, which allows one to reduce the dimension of integration. The results obtained using these algorithms are compared, and the advantages and disadvantages of both algorithms are discussed.

In this Letter, results of measurements of radiation losses Prad and effective ion charge Zeff in the conditions of magnetic field up to 0.7 T and plasma current up to 300 kA for a wide range of electron density first obtained on the Globus-M2 tokamak are presented. The analysis of the results shows the decrease in the radiation losses share of the input power on the Globus-M2 tokamak as compared with the same parameter for the Globus-M facility. A large dip at the center of the Prad power profiles is revealed. A decrease in the Zeff values is observed with an increase in electron density.

On the spherical tokamak Globus-M2 in discharges with toroidal magnetic field of 0.7 T by means of magnetic probes and a number of other diagnostics during neutral beam injection at the current ramp up stage, magnetic field oscillations in the range of 100–300 kHz having their frequency increasing in time, had been observed. Eigenmodes with wavenumbers n = 1–3 and m = 2–4 were being registered. These oscillations were identified as Alfven cascades. By means of multi-channel fluctuation reflectometer, observed eigenmodes were found to be localized near the magnetic shear reversal radius. Application of MHD-spectroscopy technique allowed us to determine safety factor temporal evolution and experimental values are in well agreement with modelling results, provided by ASTRA transport code.

Investigation of the 7H-system in the experiment conducted at the fragment separator ACCULINNA-2 in the 8He(2H,3He)7H reaction requires to detect the recoil 3He ions with energy down to 6 MeV. For this purpose two $$\Delta E{\text{—}}E$$ particle telescopes are used, with each telescope having in front a thin (20-μm) Si strip detector ($$\Delta E{\text{—}}SSD$$). The maps of thickness heterogeneity of the thin detectors were determined by measuring the energy losses of the 226Ra α-particles. The adopted thickness normalization method provides a good identification of the 3He nuclei being recorded in the presence of a high 4He background. Two approaches were used for calculating the energy losses of the identified 3He and 4He reaction ejectiles and reconstructing their energy values available at the exit from the deuterium target. The developed techniques were applied for the 7H missing-mass reconstruction.

A new readout system for strip semiconductor detectors has been developed based on a dedicated IDE1140 chip. The system consists of 64 spectrometric channels that provide readout of signals from detector strips. The source of the trigger signal can be either an external signal or a detector that measures the passage of an ionizing particle through the strips. The amplitude of the signal from this detector can also be used for particle spectrometry. The control and signal-readout unit for the IDE1140 chip has been designed on an EP3C16Q240 field-programmable gate array and is used for processing, storage, and transfer of acquired data. The main characteristics of the system are presented: the integral nonlinearity is

The development of the physicochemical basis for applications of nanoradiosensitizers for targeted treatment of tumors is one of the crucial issues of modern radiotherapy. Ceramic nanoparticles (NPs) composed of heavy metal oxides are considered as prospective sensitizers, particularly for X-ray treatment. This study reports a novel approach for experimental simulations of the radiosensitizing effect of NPs in biomimetic systems based on the quantification of radicals produced from organic components in concentrated aqueous organic solutions using the spin-trapping technique with electron paramagnetic resonance detection. This approach was first applied to X-ray irradiation (45 kVp) of aqueous methanol solutions systems containing different concentrations of hafnium oxide nanoparticles with an average diameter of ca. 84 nm (up to 1.8 wp). It was found that the amount of radicals produced from methanol at the same exposition time increased linearly with the increasing content of HfO2 NPs. The effect can be...

Studies of radioactive ions (RIs) are the most thriving field of low-energy nuclear physics. In this paper, the concept and the scientific agenda of the prospective accelerator and storage ring facility for RI beam (RIB) research are proposed for a large-scale international project based at the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research. The motivation for the new facility is discussed and its characteristics are briefly presented and shown to be comparable to those of advanced world centers, the so-called “RIB factories”. In the project, the emphasis is made on studies with short-lived RIBs in storage rings. A unique feature of the project is the possibility of studying electron–RI interactions in a collider experiment to determine the fundamental properties of nuclear matter, in particular, electromagnetic form factors of exotic nuclei.

The actual tasks of 3D-reconstruction of the industrial-urban environment and navigation models are considered by solving the identification of textured linear objects in the process of movement according to the onboard complex and technical vision system consisting of a mutually adjusted 3D laser sensor and a video camera with a common viewing area. For a complete solution of the navigation task (determination of three linear and three angular coordinates of the control object), it is necessary to select and identify at least three mutually non-parallel flat objects in the process of moving in a sequence of point clouds formed by a 3D laser sensor. In the case of the allocation of less than three flat objects (for example, in environments subjected to destruction), the navigation problem is not fully solved (not all coordinates are determined unambiguously, and some coordinates are related by linear or non-linear dependencies). In these cases, it is proposed to additionally use the texture of the selected flat objects formed by the video camera. In the paper is given the analysis of the features of the solution of the navigation problem is carried out depending on the number of allocated and identifiable textured linear objects in the current integrated images and algorithms for solving the navigation problem are evaluated for selecting and identifying the process of movement of one textured linear object and of two textured non-parallel linear objects. It is shown that in the first case, the use of texture makes it possible to reduce the solution of the navigational problem to a three-dimensional one, and in the second case to a one-dimensional optimization problem (finding the global optimum of a functional three and one variable, respectively). The proposed algorithms for processing complexed images provide a complete solution to the navigation task even if less than three linear objects are selected, which significantly increases the reliability of solving the navigation task and building an environmental model even in industrial-urban environments that have been destroyed, and therefore, the reliability and survivability of the ground ones and airborne robotic tools in autonomous modes of movement. The results of the corresponding software and hardware solutions in real industrial-urban environments, confirmed the accuracy and effectiveness of the proposed algorithms.

Experimental coordinate characteristics of magnetic field induction and its gradient are obtained between pole pieces of Faraday balance electromagnetic system. Pole pieces have spheric form that is preferable by possibility of obtaining area with a stable gradient as a working area for specimen’s positioning. Alternative characteristics which are obtained by modeling at the program COMSOL Multiphysics are shown using the same values of supply current and distance between pole pieces as at the experiment. It is shown that together with qualitative commonality of model and experimental characteristics difference of its data at the working area are up to 11 % (by induction), 24 % (by gradient), hereby testify about probable error of conclusive result which is up to 35 %, and up to 5 % by coordinate of gradient extremum. Questions about determining correction factor are discussed (normalizing factor for model characteristic); at its proved value equals 0,86 (e.g. at starting exclude of 14 % «systematic» error, probably obtained at the case of using results after modeling) a differences of mentioned data are up to 4, 5, 5% accordingly.

The possibility of using spherically shaped pole pieces to perform the Faraday balance method for measuring the magnetic susceptibility of samples is considered. The families of the coordinate characteristics of the magnetic induction between the pole pieces have been obtained experimentally. The position of the working region (the place for positioning the sample) has been determined: it is located in the vicinity of the inflection point of the induction characteristic or the extreme point of the gradient characteristic. It has been established that the position of the inflection point does not depend on the current load of the winding.

Experimental study of thermal energy confinement in magnetic confinement devices is one of the fundamental problems in plasma physics. The data processing technique covering kinetic and magnetic measurements performed for the Globus-M tokamak is described. A zero-dimensional code has been developed on the basis of this approach making it possible to calculate important discharge parameters during the experiment (between discharges): the electron and ion stored thermal energy content, plasma effective charge, and confinement time. Good agreement of the zero-dimensional calculations and ASTRA modeling indicates that this approach can be applied for routine data processing in Globus-M in view of the specifics of the device.

A major obstacle in developing upconversion aerogels is the incompatibility of the highly-developed porosity and the crystal structure required for converting light to a shorter wavelength. We propose a novel method for creating a sol–gel procedure for synthesizing metal (Zr, Hf, and Ta) oxide upconverison aerogels uniformly doped with Er3+ and Yb3+ by precisely adjusting the calcination conditions.

Active ion temperature measurement in the core plasma of a tokamak using active neutral particle analyzers (NPA) diagnostics is considered. Two approaches for local ion temperature reconstruction are reviewed: semi-analytical and iterative. A semi-analytical approach allows the calculation of ion temperature using simple expression, while a more complex iterative approach provides more flexibility. Problems associated with active NPA measurements and their possible solutions are discussed. An example of the core ion temperature profile reconstruction in the compact spherical tokamak Globus-M2 using both approaches is shown. Problems associated with active ion temperature measurements in a compact reactor and possible solutions are considered.

The paper describes the digital filter polychromator developed for Thomson scattering (TS) diagnostics. The device having ultra-low noise, high-speed detection system and up to 7 spectral channels is equipped with digitizer and single board computer for system control and data processing. The data acquisition system is capable to detect very short laser pulses of few ns width with low magnitude. This feature opens up new possibilities for the TS diagnostics design in modern fusion devices, which includes: operation with high background illumination, measurement of very low electron temperature and density at the plasma edge and scrape-off layer (SOL), separation of the TS signal and the stray light coming with a delay of several ns. The analysis of the TS signal waveform also gives a possibility to distinguish the TS and Mie scattering from the dust particles that is important for measurements in SOL. Owing to compactness and ultra-low energy consumption both optical and data processing units interfaced with optical Gigabit Ethernet were combined in a stand-alone device. Such all-in-one design with optical fiber input and optical digital output provides enhanced resistance to electromagnetic disturbances and simplify operation. A set of such polychromators can be mounted in a standard 19” rack and can be integrated with outer CODAC (Control, Data Access and Communication) system. Testing of the polychromators at the Globus-M2 tokamak has shown excellent performance of the developed serial devices.

The conventional method for determining the effective ion charge Zeff is based on measurements of the bremsstrahlung intensity in the spectral regions free from line radiation. This paper describes the design of the Zeff diagnostics at the Globus-M tokamak as well as the results of the first measurements. With allowance for the emission intensity estimates, the geometry of the experiment was chosen; the filter monochromators for recording bremsstrahlung were designed and manufactured. Using the Thomson scattering data on T e (R) and n e (R) profiles, time dependences Zeff (t) were obtained in several shots of the Globus-M tokamak. The results of simulations Z eff performed using the ASTRA transport code are consistent with these measurements.

A fast scanning probe which can penetrate inside the separatrix during discharge was developed for Globus-M2. The probe has been designed to move various sensor pins into the scrape-off layer. The driving force is provided by a crank-slider mechanism which is ensured maximum linear speed about 4 m/s. The paper presents probe head and drive system description.

A solid-phase photosensitizer based on aggregated C60 fullerene and graphene oxide for photodynamic inactivation of pathogens in biological fluids was studied. The most promising technologies of inactivation include the photodynamic effect, which consists in the inactivation of infectious agents by active oxygen forms (including singlet oxygen), formed when light is activated by the photosensitizer introduced into the plasma. Research shows features of solid-phase systems based on graphene and fullerene C60 oxide, which is a combination of an effective inactivating pathogens (for example, influenza viruses) reactive oxygen species formed upon irradiation of the photosensitizer in aqueous and biological fluids, a high photostability fullerene coatings and the possibility of full recovery photosensitizer from the biological environment after the photodynamic action.

Due to rapid development of the scientific and applied research in magnetic control and magnetophoresis of ferro- and ferromagnetic disperse fraction of various technological, natural and industry-specific media, the Faraday method is again in high demand as it is mainly aimed at defining magnetic susceptibility of solid and heterogeneous samples of small volumes. Based on the appearing (and then measured) ponderomotive force impacting the sample, the method allows accurate determining of single particles magnetic susceptibility by using the data of the sample represented by a conglomerate of the particles of such a fraction. In addition, it is mentioned that to date there is still a great gap in the methodology of the Faraday method as there are no exact recommendations on choosing both the form of the polar pieces of the Faraday balance and the positioning of the sample (the location of the working zone) in the interpolar area. Owing to these drawbacks, the well-known and long-time used Faraday method cannot be considered substantiated to a satisfactory degree. Thus, in our point of view, the treatment of the results obtained earlier with the help of the method should be cautious. In our work, we experimentally defined and substantiated an approach to identifying a working (local) zone, viz. the zone with stable values of the magnetic force factor – the product of the field intensity and induction by its gradient. The approach features the relative phenomenological analysis and is exemplified by polar pieces of non-traditional spherical form. It has been demonstrated that in order to state the fact of mere existence of this zone (and its location) in the interpolar area, the coordinate (usually nonlinear one) characteristic of intensity or induction, which is obligatorily obtained in an experiment, should have an inflexion, which guarantees a functionally extreme view of the following coordinate characteristics both of the gradient and that of the force factor. We also established the coordinates and the length of the working zone in a specific interpolar area.

The MEG experiment at PSI searches for the decay μ → e γ at a level of ≈ 10 − 13 on the branching ratio BR ( μ → e γ / μ → tot ), well beyond the present experimental limit ( BR ≤ 1.2 × 10 − 11 ) and is sensitive to the predictions of SUSY-GUT theories. To reach this goal the experiment uses one of the most intense continuous surface muon beams available ( ≈ 10 8 μ / s ) and relies on advanced technology (LXe calorimetry, a gradient-field superconducting spectrometer as well as flexible and powerful trigger and acquisition systems). In order to maintain the highest possible energy, time and spatial resolutions for such detector, frequent calibration and monitoring, using a Cockcroft–Walton proton accelerator, are required. The proton beam is brought to the centre of MEG by a special bellows insertion system and travels in a direction opposite to the one of the normal μ ‐ beam . Protons interact with a lithium tetraborate (Li2B4O7) nuclear target and produce one γ (17.6 MeV) from the reaction Li ( p , γ ) 3 7 Be 4 8 or two coincident γ s (11.67 and 4.4 MeV) from the reaction B ( p , γ 1 ) 5 11 C ⁎ 6 12 . The 17.6 MeV γ is used for calibrating and monitoring the LXe calorimeter ( σ E γ / E γ = 3.85 ± 0.15 % at 17.6 MeV) while the coincident 11.67 and 4.4 MeV γ s are used to measure the relative timing of the calorimeter and the spectrometer timing counters ( σ Δ t = 0.450 ± 0.015 ns ).

The Globus-M2 spherical tokamak is the considerably upgraded Globus-M facility. Its technical parameters were increased as much as possible to achieve the promising range of physical parameters (sub-fusion temperatures and collisionality of much less than unity). These parameters will be achieved in a compact magnetic configuration similar to that of the Globus-M tokamak, the plasma current and toroidal magnetic field amounting to 0.5 MA and 1 T, respectively. The demand to increase the magnetic field and plasma current in the Globus-M2 resulted in the need for a complete redesign of the electromagnetic system because the plasma equilibrium requirements have changed and the mechanical and thermal loads have considerably increased as compared to the Globus-M. The vacuum vessel and the in-vessel components of the new Globus-M2 tokamak remain the same. Power supplies were upgraded to provide the required currents in the toroidal field coil and the central solenoid. The Globus-M2 tokamak was build up and preliminary tests were carried out. New auxiliary heating systems and diagnostics were developed and installed to be used in future experiments. Fist plasma was achieved at the Globus-M2 in April 2018.

Analysis of stability of the peeling-ballooning modes in the edge plasma of the Globus-M tokamak is presented. Studies were performed using the ideal 3D MHD code written in the BOUT++ framework. The edge localized modes which are frequently observed in the Globus-M plasma could be described using MHD theory. It was found that the parameters of the Globus-M edge plasma are in the range of stability for the peeling-ballooning modes. The instability modes with a toroidal number of n = 12 and typical distances between filaments of approximately ~12 cm were found to be the most unstable. This statement agrees with the Doppler backscattering measurements. It was also considered whether the plasma in the Globus-M2 tokamak will be stable against the PB instability.

In Faraday's magnetometer it is recommended to apply remotely the located poles hemispheres. In this case (and similar cases) there is a need for expeditious and exact positioning of the measuring sensor (Hall) and the studied sample – for obtaining the most authentic characteristics of induction and its gradient, identification and use of a zone of stability. This problem is solved by the corresponding opticalmechanical system of positioning. It consists of the laser modules promoting aim positioning, the Web camera promoting final positioning. On the received concentration dependences of magnetic susceptibility of powder samples existence of limited line sections is confirmed that gives the chance to define susceptibility of particles. The critical relation to use for the similar purposes of samples (disperse) in the form of colloids and suspensions expresses.

The QTG quadrupole magnets will be a part of the CERN Neutrino to Gran Sasso (CNGS) transfer line. 23 QTG magnets will be used as lattice and matching quadrupoles. They are being produced in the framework of a German in-kind contribution via DESY to CNGS. The QTG magnets have a maximum gradient of 40 T/m at the 530 A excitation current and are manufactured from laminated steel cores. The yoke length is 2.2 m and the inscribed radius is 22.5 mm. The excitation coils are made of vacuum impregnated hollow copper conductor. The main design aspects and the results of the acceptance tests including mechanical, electrical and magnetic field measurements are described.

Presented are the main design features of the large cathode strip chambers (CSCs) for the CMS endcap muon system as well as the performance results obtained with the first large-scale prototype. The 3.4×1.2 m 2 six-plane prototype has been reliably operated over one year and the cosmic-ray tests showed that it was capable of detecting muons with ∼80 μm spatial and ∼5 ns time resolutions.

The energy-sensitive detection of heavy ions with calorimetric low temperature detectors was investigated in the energy range of E=0.1-1 MeV/amu, commonly used for accelerator mass spectrometry (AMS). The detectors used consist of sapphire absorbers and superconducting aluminum transition edge thermometers operated at T approximately 1.5 K. They were irradiated with various ion beams (13C, 197Au, 238U) provided by the VERA tandem accelerator in Vienna, Austria. The relative energy resolution obtained was DeltaE/E=(5-9) x 10(-3), even for the heaviest ions such as 238U. In addition, no evidence for a pulse height defect was observed. This performance allowed for the first time to apply a calorimetric low temperature detector in an AMS experiment. The aim was to precisely determine the isotope ratio of 236U/238U for several samples of natural uranium, 236U being known as a sensitive monitor for neutron fluxes. Replacing a conventionally used detection system at VERA by the calorimetric detector enabled to substantially reduce background from neighboring isotopes and to increase the detection efficiency. Due to the high sensitivity achieved, a value of 236U/238U=6.1 x 10(-12) could be obtained, representing the smallest 236U/238U ratio measured at the time. In addition, we contributed to establishing an improved material standard of 236U/238U, which can be used as a reference for future AMS measurements.

The full energy booster injector for the Duke FEL storage ring is presently under installation [2]. The booster is designed to provide continuous injection into the Duke FEL storage ring in top-off mode at the energy variable from 0.27 GeV to 1.2 GeV. The magnetic elements for the booster have been fabricated and magnetically measured at Budker Institute of Nuclear Physics, Russia. The paper presents magnetic and mechanical design of the booster dipole and quadrupole magnets and results of their magnetic measurements. Results of simulation of the booster lattice taking into account residual field and non-linearity of the magnets are also presented.

In the Large Hadron Collider (LHC), two straight sections, IR3 and IR7, will be dedicated to beam cleaning. These cleaning insertions will be equipped with normal conducting magnets. MBW magnets are dipole magnets used to increase the separation of the two beams. They have a core length of 3.4 m and a gap height of 52 mm and will operate at a magnetic field ranging from 0.09 T to 1.53 T. Limitations on the dimensions and total weight of the magnet resulted in a special design with a common yoke for the two beams. The orbits of the two beams will be separated horizontally by a distance between 194 mm and 224 mm in the gap of the magnet. The magnet was designed in collaboration between CERN and BINP. The report presents the main design issues and results of the pre-series acceptance tests including mechanical, electrical and magnetic field measurements.

Design and construction details are presented of a four-layer, position sensitive, cathode strip chamber and a low cost, highly multiplexed readout system based on monolithic circuit technology that are well suited for a muon detector at future hadron colliders. Track location is determined by interpolation of the cathode induced charge, using a new design with intermediate strips between readout nodes to reduce the number of channels and improve position resolution and linearity. Results are reported from tests with an 55 Fe source and a 300 GeV/ c muon beam in RD5 at CERN. The beam test demonstrated position resolution of 40 μ m per layer which is less than 1% of the readout pitch. The timing resolution for the entire four-layer detector was 3.6 ns r.m.s. which is adequate for fully efficient beam crossing identification in an LHC experiment.