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Preprints and Communications

Here you can find JINR preprints and communications in pdf format starting from 1999.
File size is given in bytes in round brackets.

Subject Categories for JINR Publications Archive (1999 - 2017)


2018
E11-2018-43 (178.602)
Török Cs.
Speedup of Interpolating Spline Construction

The article introduces an efficient sequential algorithm for computing spline coefficients. The aim is to decrease the computational time. A reduced-size tridiagonal system of linear equations is constructed based on a recently derived relation for the unknown coefficients of uniform cubic splines of class C2 at the odd grid points. The even coefficients are computed from an explicit formula. Thanks to the half-size system and use of a simple formula, the suggested new sequential algorithm needs less division than the traditional one and it results in a non-negligible computational speedup. Finally, a general approach to dyadic reduction of the dimensionality of tridiagonal linear systems is proposed in consequence of which the size of the systems gradually shrinks to half, quarter, etc.

E13-2018-37 (434.371)
Bielewicz M. et al.
MCORD MPD Cosmic Ray Detector for NICA

The Multi-Purpose Detector (MPD) is a part of the Nuclotron-based Ion Collider fAcility (NICA) located in Dubna, Russia. For full functionality, the MPD needs an additional trigger system for off-beam calibration of MPD subdetectors and for rejection of cosmic ray particles (mainly muons). The system could also be useful for astrophysics observations of cosmic showers initiated by high energy primary particles. The consortium NICA-PL composed of several Polish scientific institutions has been formed to define goals and basic assumptions for MPD Cosmic Ray Detector (MCORD). This article describes the early stage design of the MCORD detector based on plastic scintillators with silicon photomultiplier photodetectors for scintillation readout and of the electronic system based on MicroTCA crate. Plans for simulations of MCORD detector performance are also presented.

E13-2018-30 (259.663)
Chirikov-Zorin I. et al.
Performance of Shashlyk Calorimeter Read Out by SiPMs with High Pixel Density

The matrix of 3 × 3 modules of the EM calorimeter ECAL0 (COMPASS II) read out by MPPC S12572-010P SiPM with the pixel density of 104 mm-2 and an area of 3 × 3 mm is studied in the range of electron energies 130 GeV. It is observed that MPPC has additional response nonlinearity and a significantly smaller dynamic range of output signals than expected. The mechanism of the effect based on the influence of parasitic capacitance between pixels on the pixel gain is proposed. The energy resolution of the calorimeter is measured to be (σE/E) = (7,1%/√E)(1+0,06/E)⊕1,4%E0,25

P13-2018-28 (1.160.652)
Pepelyshev Yu. N., Rogov A. D., Sidorkin S. F.
Optimization Study of the Accelerator-Driven Multiplying Pulsed Neutron Sources

The neutron source operating at the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research (Dubna) on the base of the IBR-2M pulsed reactor with the flux density of thermal neutrons ∼ 1013cm-2 · s-1 will exhaust its resource and be shut down by 2034. It is proposed to consider the proton-driven subcritical pulsed neutron source instead of the IBR-2M. At present, the world mostly uses the nonmultiplying neutron sources based on the high-current proton accelerators, for example, SNS or ESS with a beam power of 3 and 5 MW, respectively. We present the computational comparison of the various categories of the high-current proton accelerator-driven pulsed neutron sources in order to select the most optimal solutions. The one-zone booster with a tungsten target and the core with plutonium dioxide which can be a promising option is shown. For such a source, it is possible to obtain an average thermal neutron flux density of more than 5.0 · 1014 cm-2 · s-1 at a proton beam power of 0.10.2 MW.

P10-2018-23 (549.125)
Kirilov A. S., Morkovnikov I. A.
About the Concept of the File Repositary for Istruments at the IBR-2 Pulsed Reactor

The work is devoted to the concept of a central repository of measurement data from the IBR-2 instruments at the FLNP, JINR. The concept takes into account the variety of structures and data file formats on specific instruments, the users' wishes, and estimated amount of disk space required. The questions of the service organization for the work with the data into the storage were considered, taking into account the existing system of automatic measurements registration Journal.

E13-2018-22 (622.408)
Korepanova N. V. et al.
Neutron Noise Analysis Using the Basic Element Method

The full range of noise energy pulses reaches ±22% under normal conditions of operation of the IBR-2M reactor (JINR, Dubna). Therefore, slow changes in average power, caused, for example, by the movement of regulatory bodies, “drown” in the noises. But in a number of cases, it is these slow components of the pulse energy variation, the so-called basic signals (baseline), that are of fundamental importance for justifying the conditions for safe operation of the reactor. To determine the baseline in the noises of the IBR-2M the sixth order mean-square piecewise polynomial approximation (MSPPA-6) was used for the detection of the baseline in the noises of IBR-2M. The algorithm MSPPA-6 depends on control parameters α, β, M and K, the optimal values of which depend on the initial noise parameters. The algorithm was applied to both the static and the dynamic state of the reactor in the range of an average power of 30 kW 2 MW. The average processing time of one point on a PC x86_64 Processor Intel Core i5-4570 Sandy Bridge machine, 3.20 GHz, was 0.05 ms, which allows using the MSPPA-6 algorithm in real time.

P3-2018-20 (552.724)
Zakharov M. A. et al.
Numerical Simulation of the Experiment on Observing Non-Stationary Diffraction of UCNs on a Moving Lattice

A set of programs has been created for modeling the experiment to study UCN diffraction on a moving grating. The problem of diffraction of neutrons on a lattice with parameters corresponding to the actual experiment was solved numerically on the basis of the equations of the dynamic theory of diffraction. The process of measuring the diffraction spectrum by a time-of-flight Fourier diffractometer was simulated by the Monte Carlo method. Systematic errors in the reconstruction of the neutron energy spectrum by the inverse Fourier spectrometry method are investigated. The results of numerical calculations are compared with experimental data.

E1-2018-18 (763.504)
Suchopár M. et al. (on behalf of the Collaboration “Energy and Transmutation of Radioactive Waste”)
Activation Measurement of Neutron Production and Transport in a Thick Lead Target and a Uranium Blanket during 4 GeV Deuteron Irradiation

Several simple accelerator-driven system (ADS) setups were irradiated with relativistic proton and deuteron beams in the last years at the Nuclotron synchrotron site of the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. This paper is dedicated to a 4 GeV deuteron irradiation of a setup called Energy plus Transmutation (E + T), consisting of a lead target, natural uranium blanket, and polyethylene shielding. This paper represents the finalization of data analysis and concludes systematics of the proton and deuteron experiments carried out with the E + T setup. Activation detectors served for monitoring of proton and deuteron beams and for measurements of neutron field distribution in model ADS studies. Products of reactions with thresholds up to 106 MeV as well as non-threshold reactions were observed in the samples. The yields of the produced isotopes were determined using the gamma-ray spectrometry and compared with Monte Carlo simulations performed with the MCNPX transport code.

P11-2018-17 (311.312)
Ayryan E. A., Malykh M. D., Sevastianov L. A.
Finite Differences Method and Integration of the Differential Equations in Finite Terms

We show that standard approaches to integration of the differential equations in finite terms contain the reference to numerical methods of the last centuries. Further we describe the class of the differential equations of the first order allowing good differential schemes. This means that the calculation by such scheme can be continued after mobile singularities. After necessary introduction we describe such one-to-one scheme for the Riccati equation and prove its property mentioned above. In conclusion we present n-to-n schemes for 1st order differential equations as their natural generalization. Here we prove that one-to-one schemes exist only for the Raccati equation and investigate conditions of existence of 2-to-2 schemes.

E1-2018-11 (1.393.237)
Tokarev M. (on behalf of the STAR Collaboration)
Recent STAR Spin Results and Spin Measurements at RHIC

The STAR experiment provides measurements of single- and double-spin asymmetries in longitudinally and transversely polarized p+p collisions at √ s = 200 and 510 GeV to deepen our understanding of the proton spin structure and dynamics of parton interactions over a wide range of collision energy, momentum and rapidity of the various produced probes. Polarized processes with W± production allow us to study the spin-flavor structure of the proton. Recent results obtained by STAR on the double longitudinal asymmetry, ALL, of pion and jet production at √ s = 200 and 510 GeV, the single longitudinal, AL, and transverse, AN, asymmetry of W± production at √ s =510 GeV are overviewed. STAR results on azimuthal single transverse asymmetry of pion in p↑ + (p, Au)- and jet + π± p↑ + p collisions are discussed. The proposed Forward Calorimeter System (FCS) and Forward Tracking System (FTS) upgrades at STAR would significantly improve the capabilities of existing detectors for measurements of observables such as asymmetries of pion, jet, DrelYan pairs produced at forward rapidities.

E3-2018-7 (250.576)
Granja C. et al.
Two Methods of Determination of Parities of Low-Lying States in 159Gd from Analysis of γ-Ray Intensities from 158Gd(nres,γ)159Gd Reaction

Energy levels and transitions in 159Gd were studied by means of radiative capture of resonance neutrons in 12 isolated resonances of 158Gd. The time-of-flight technique was used on an enriched target at the IBR-30 reactor at JINR, Dubna. A total of 80 primary gamma transitions were recorded, and their absolute intensities were determined resulting in the observation of 1/2± and 3/2± levels up to 2.4 MeV. Parities of the found levels were recalculated using two methods: the first method consists in analyzing of intensities averaging in 12 resonances, and in the second method individual intensities are analyzed. The second method is described for the first time.

P11-2018-6 (746.926)
Akishin P. G., Sapozhnikov A. A.
The Integral Formulation of the Magnetostatic Problem for Magnetic System Modelling

We consider the application of the volume integral method to the magnetic system calculations. The major stages of modelling process are discussed: the discretization of initial equations, the description of the algorithm for dividing the area into elements, the calculation of matrix elements for discretization problem and the solution for the obtained system of non-linear equations. The results of modelling of magnetic systems using the discussed method are presented and compared with calculations performed by other programs.

P2-2018-4 (837.094)
Sinegovsky S. I., Sorokovikov M. N.
Prompt Atmospheric Neutrinos in the Quark-Gluon String Model

We calculate the prompt atmospheric neutrino flux in the energy range 1105 TeV arising from decays of the charmed particles. Cross sections of the D-mesons and Λc-baryons production in pA- and πA-collisions are calculated in the framework of the phenomenological quark-gluon string model, free parameters of which were improved using measurement data of the LHC experiments. Predicted prompt neutrino flux is compatible with the constraint obtained in IceCube experiment. Also we compare our calculation with other predictions obtained for different charm production models.

P15-2018-3 (4.377.077)
Didyk A. Yu. et al.
Synthesis of Solid-State Structures and Chemical Elements under Irradiation by Bremsstrahlung γ Rays with a Maximum Energy of 10 MeV in Condensed Deuterium at a Pressure of 2.2 kbar

A high-pressure chamber filled with deuterium (DHPC) under initial pressure 2.2 kbar was irradiated during 49 h by bremsstrahlung γ rays with a maximum energy of 10 MeV. After irradiation, several particles with dimensions up to 1 mm fell out of the DHPC. On the inner surfaces of the DHPC, newly formed solid micro-objects were found in the form of crystalline and amorphous microparticles, filaments, nodules and inclusions. Investigations of the elemental composition of the revealed structures, carried out with the help of X-ray microprobe analysis, showed the presence of chemical elements in them, which were absent in the reaction chamber prior to the onset of irradiation. The following chemical elements were registered: 6C, 7N, 8O, 11Na, 12Mg, 13Al, 14Si, 15P, 16S, 17Cl, 19K, 20, 21Sc, 22Ti, 24Cr, 25Mn, 26Fe, 28Ni, 30Zn, 33As, 50Sn 82Pb. The experiment on the synthesis of chemical elements in deuterium confirms the results of previous experiments performed with other gases: hydrogen, helium and xenon.

2018-1 (14.227.816)
Brief Review of Topmost Scientific Results Obtained in 2017 at the Joint Institute for Nuclear Research



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