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P4-2020-40 (360.365)
Efimov A. D., Izosimov I. N.
Description of the States of the Yrast-Band in 156Dy
Based on an extended microscopic version of the IBM1, a description
of the properties of the yrast-band states in 156Dy up to
spin 18+ is obtained. The series of states of this band, 6+, 8+ и 10+, are populated from 8+ (2.788 MeV) excitation
by-turn populated as a result of β+/ЕС-decay from the
isomeric state 9+ в 156Ho.
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E1-2020-38 (459.324)
Cordun C. M. et al.
The First Cosmic Ray Measurements for Future MCORD Project
Multi-Purpose Detector (MPD) is the main detector set for the future
Nuclotron-based Ion Collider fAcility (NICA) located in Dubna, Russia. The
MPD needs an additional trigger system for off-beam calibration and for
rejection of cosmic ray particles (mainly muons) for full functionality. The
prototype Cosmic Ray measurement system for MPD detector is under
development. It is called the MPD Cosmic Ray Detector (MCORD). For
calibration results of Extended Cosmic Shower (ECS) simulation we need the
real Cosmic Ray (CR) measurement results performed at the NICA location.
This paper describes the first CR measurements done with the CosmicWatch
simple detectors based on the small 5 ⨯ 5 cm plastic scintillators with silicon
photomultiplier (SiPM) photodetectors.
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E1-2020-37 (336.473)
Bielewicz M. et al.
The Cosmic Ray Detector for the NICA Collider
Multi-Purpose Detector (MPD) is the main part of a new Nuclotron-based Ion Collider fAcility (NICA) located in Dubna.
To increase MPD functionality, it was proposed to install an additional muon trigger system for off-beam calibration of the MPD sub-detectors
and for rejection of cosmic ray background during experiments. The system could also be very useful for astrophysical observations of cosmic
showers initiated by high-energy primary particles. This article describes the main goals of MCORD detector and the early stage of MCORD design,
based on plastic scintillators with silicon photomultiplier photodetectors (SiPM) for scintillation readout and electronic system based on MicroTCA standard.
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E3-2020-36 (509.849)
Ndlovu N. et al.
Measurements of Cross Sections for High-Energy Neutron-Induced Reactions on Co and Bi
There are few experimental data for neutron cross-section libraries for (n,xn) reactions in various materials for energies above 20 MeV.
For high energies (above 20 MeV), these sets of (n,xn) reactions are important for neutron fluence monitoring and spectra unfolding for future generation
IV nuclear reactors. There were attempts to measure the cross sections on natural cobalt and bismuth at incident neutron energies of about 90 and 140 MeV.
These measurements were made using the quasi-monoenergetic neutron facility at iThemba LABS, South Africa. In addition, using high energy neutrons at the
Svedberg Laboratory in Sweden, similar experiments were performed on natural yttrium. The measured cross sections are compared with some of the few available
cross-section measurements for neutron-induced reactions at high energies. The data obtained using facilities at both labs required corrections to be made for the
contribution of the low-energy tail (continuum) in the incident neutron spectrum in these measurements.
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E13-2020-35 (399.280)
Bancer A. et al.
Radiation Monitoring of the Slow Control Electronic Equipment of the NICA-MPD Detector
One of the components of the Nuclotron-based Ion Collider fAcility
(NICA) Complex being built at JINR
(Dubna) is Multi-Purpose Detector (MPD). Its work is monitored and
controlled by the Slow Control system. The electronic equipment of this
system is placed in the racks located on the multilevel mechanical support
construction. “The prototype dosimetry system to protect NICA Slow Control
electronic equipment” project was started to design a prototype dosimetry
system for continuous monitoring of the MPD Slow Control electronic devices
to protect it against accidental ionizing radiation. The system will be fitted
out with alarming features to inform the chosen persons about crossing a
safe threshold of the radiation above which the electronics will be possibly
destroyed by the irradiation. The article describes the
actual state of this system and the plans for its upgrading. Logical structure of the control program and its
functionality are shown in detail.
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E13-2020-34 (327.926)
Kolasiński P. et al.
Electronic Readout System Designed for MCORD in the NICA Experiments
Multi-Purpose Detector (MPD) system is a part of new accelerator complex
(Nuclotron-based Ion Collider fAcility — NICA) located in Dubna (Russia).
To meet all functionalities and requirements of MPD, another trigger
system should be designed. That trigger system has two main tasks: first, responsibility for
off-beam calibration of MPD subdetectors, and second, identification and
rejection of cosmic-ray particles. Additionally, the system can be used
to observe cosmic showers initiated by high-energy primary particles. To
define in detail requirements of the MPD Cosmic Ray Detector (MCORD), the NICA-PL
consortium has been formed. Many Polish scientific institutions participate in it. This paper presents an electronic readout
system for the MCORD project. It briefly describes the data path of the
signals and all signal processing subsystems: scintillators equipped with
SiPM detector, Analog Front-End (AFE), HUB, and
MTCA processing system.
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E1-2020-33 (299.099)
Szuta M. et al.
Average High Energy Neutron Flux Distribution in the Quinta Subcritical Assembly Irradiated with Proton Beam of 0.66-GeV Energy Applying the Actinide Spectral Index Method
To evaluate the high energy neutron flux distribution, twenty three natural
uranium samples were spatially arranged in the Quinta subcritical assembly (at
the Joint Institute for Nuclear Research, Dubna). The samples were
irradiated with spallation neutrons. When the ratio of fission cross section
to capture cross section of the natural uranium for the distinct neutron
energy from the nuclear data base is equal to the measured ratio of
spectral indexes, it enables us to evaluate the average neutron flux
distribution in the assembly.
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E1-2020-32 (191.893)
Bielewicz M., Kankiewicz P., Chlopik A.
Minimum Resolution of MCORD as a Consequence of Astrophysical Observation Requirements
The Multi-Purpose Detector (MPD) needs an additional trigger system for off-beam calibration
and rejection of cosmic ray particles for full functionality. The prototype cosmic ray measurement system for the
MPD detector is under development and is called the MPD Cosmic Ray Detector (MCORD).
It can detect muons coming from all directions between zenith and horizon, with information about particle direction vector.
Theoretically, it is possible to recognize the extragalactic source of a cosmic particle but only in case of Ultra-High Energy Cosmic Rays (UHE CR)
connected to Extended Cosmic Showers (ECS). We need to use the optimal MCORD position resolution to identify the possible sources on the celestial sphere.
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P3-2020-31 (671.936)
Aksenov V. L., Rzjanin M. V., Shabalin E. P.
JINR Research Reactors: A Look into the Future
The concept of a new pulsed reactor IBR-3 ("Neptun") is presented,
which in terms of its parameters is superior to the existing pulsed sources,
as well as to those which are being constructed, for research on extracted beams.
A scientific program, the implementation of which is difficult or impossible with existing sources,
as well as the infrastructure for supporting experiments, is briefly discussed.
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E2-2020-24 (700.144)
Zborovský I., Tokarev M.
Self-Similarity, Fractality and Entropy Principle in Collisions of Hadrons and Nuclei at Tevatron, RHIC and LHC
The z-scaling of inclusive spectra as a manifestation of self-similarity and fractality of hadron interactions is illustrated.
The scaling for negative particle production in Au+Au collisions from BES-I program at RHIC is demonstrated.
The scaling function ψ(z) as a function of self-similar variable z depends on the model parameters — the fractal dimensions and "specific heat",
and reveals energy, multiplicity, and flavor independence.
Based on the maximum entropy principle and z-scaling,
energy loss as a function of the collision energy, centrality, and transverse momentum of inclusive particle is estimated.
New conservation law including fractal dimensions and momentum fractions is found. Quantization of fractal dimensions is discussed.
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P9-2020-22 (2.121.268)
Budagov Yu. A.
The Cooperation of JINR with the Scientific Organizations of the
Republic of Belarus in the Area of the Superconducting Accelerator Resonators
The Collaboration of Scientists and Specialists of the Republic of Belarus
from the INP and NC HEP (later merged with INP BSU) оf the BSU, BSUIR, PhTI
and SSPA NASB together with physicists of JINR developed, manufactured and
tested at liquid helium temperature of 4.2 K three prototypes of an elliptical superconducting niobium cavity at
1.3 GHz frequency for electron and positron accelerators. The work was
initiated by the International Linear Collider (ILC) project. For the first
time in Belarus, the superconducting mode of operation of the cavity has
been achieved, and the maximum value of the loaded
Q-factor of the resonator, equal to 2,8101 · 109, has been obtained with
absolute matching of the cavity with the RF-path at SWR = 1.0000.
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P2-2020-18 (423.909)
Shindin R. A. et al.
Charge-Exchange Quasi-Elastic Process nd → p(nn) at an Angle of 0°
in the Framework of Elastic np → np Scattering through an Angle of 180°
The problem of spin physics
related to the difference of representations of the elastic interaction
between the neutron and the proton is considered.
In the first case, the charge-exchange np → pn reaction
at the angle θ is supposed,
in the second – the simple elastic scattering of np → np,
when the neutron is going in the opposite direction π – θ.
The transition from one representation to another
is provided by the Majorana operator.
In the framework of impulse approximation,
the quasi-elastic charge-exchange reaction of a neutron on a deuteron is calculated twice.
In the framework of nd → p(nn) scattering of proton through
the angle θ,
the well-known Dean formula is given.
Using the other representation nd → (nn)p
as a neutron elastic scattering at the angle π – θ
(together with neutron-spectator in nn-pair),
the alternative formula is presented.
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P9-2020-17 (381.476)
Karamyshev O. V. et al.
Research and Development of the Superconducting Cyclotron SC230 for Proton
Therapy
The conceptual design of a compact superconducting cyclotron accelerating
the beam of protons to 230 MeV dedicated for proton therapy and
medico-biological research is presented.
SC230 is an isochronous four-sector compact cyclotron with a magnetic field
in the center of 1.7 T. Superconducting coils will be enclosed in a
cryostat, all other parts of the cyclotron are «warm». Acceleration is
performed at the fourth harmonic mode of the accelerating radio-frequency
system consisting of four resonators located in the cyclotron valleys.
The accelerator will use an internal Penning type source with a hot cathode.
Extraction is carried out by an electrostatic deflector located in the gap
between sectors and two passive magnetic channels.
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P10-2020-15 (1.411.432)
Dedovich T. G., Tokarev M. V.
Criteria for Reconstruction of Fractals and Suppression of Background Events by SePaC Method
Fractals and different background states (mixed, random, distributed by Gauss, power and exponent laws)
are analyzed by SePaC method aimed at search for and reconstruction of fractal structures. It is shown that part of background events is reconstructed as fractals.
Distributions of different events by the fractal dimension is studied. It is found that these distributions for fractals and background events are different.
Some characteristics describing features of fractal structures are presented and their comparison for fractals and background events
is performed. Criteria for background suppression are suggested and analysis results are presented. It is shown that application of the criteria
separately changes the background event distribution by the fractal dimension and their combination results in noticeable background suppression.
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P13-2020-14 (1.421.378)
Pepelyshev Yu. N. et al.
The Concept of a Fast Pulsed Reactor IBR-4
The high-flow pulse reactor operating in the Laboratory of Neutron Physics
IBR-2М with a neutron flux density of ∼ 1013 cm-2 · s-1 by the end of the 2030s will be exhausted and will be stopped. The
main drawback is the need to undertake significant development work with
significant financial costs and difficulty to predict final results. As an
alternative to the above-mentioned proposals, the concept of a neutron
source is given in the work, the essence of which is that the source should
be feasible, reliable and safe with minimal development and financial costs.
These conditions involve the full use of technical solutions already ready
and tested at other nuclear facilities. As a basis for further
consideration, a brief conceptual description of such a source, a pulse
reactor of periodic action IBR-4, is provided.
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P3-2020-13 (177.634)
Shabalin E. P., Rzyanin M. V.
Analysis of the Pulsed Fast Reactor “Neptun” Dynamics:
Comparison of Calculation Models
Generation of a power pulse in periodically pulsed reactor is
considered with account for fast reactivity feedback. The calculation method
includes coupled neutronic-thermoelastic equations based on one-point
kinetics of the reactor and on two models of elastic behavior of reactor
fuel rods: approximation of a reactor core as one-dimensional oscillator
and, more realistically, accounting for elastic waves propagation
through a single rod. It is shown that reasonably chosen parameters of the
oscillator model gives results close to that of the wave model.
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P16-2020-12 (124.008)
Krylov V. A., Pavlik E. E., Timoshenko G. N.
Calibration of the Neutron Multisphere Spectrometer in Open Geometry
The procedure for calibrating the neutron multisphere spectrometer with a
252Cf source in open geometry is described, and a calibration
coefficient averaged over six spheres is obtained. The results are confirmed
with unfolding the initial 252Cf spectrum by the spectrometer readings.
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P18-2020-7 (960.632)
Gustova M. V. et al.
Determination of Microelements and Radionuclides in Mushrooms from
Different Regions of Russia
The analysis of the elemental composition of wild
mushrooms that had been collected in the territory near different
cities in Russia was carried out.
Analytical determinations of 27 chemical elements and individual
radionuclides (328U, 137Cs, etc.) were performed using
nuclear-physical methods of analysis: X-ray fluorescence, gamma activation,
gamma spectrometric and track. The dependences of the content of elements
and radionuclides on the kind of the mushroom were revealed. The difference
in the index accumulation of elements in the mushrooms of various ecological
groups was shown. The kinetics of the 137Cs desorption from different
parts of the mushrooms body into the water phase was investigated. The
assumption about the possibility of the cosmic dust being on the surface of the
mushrooms was made.
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P13-2020-6 (833.968)
Pepelyshev Yu. N., Popov A. K., Sumkhuu D., Rogov A. D.
On the Limits of Oscillatory Instability of Pulsed Reactors of Periodic
Operation
On the basis of experimental and model researches carried out at the IBR-2
and IBR-2M reactors, it has been shown that pulsed reactors of periodic
operation (PRPO) have fundamental limitations on stability. At the same time
degradation changes in the core of the PRPO lead to a strong weakening of
the fast power feedback, which causes the appearance of oscillatory
instability. For safety purposes, the PRPO power even for fresh fuel is limited to 2—3
MW. There is also a strong instability of fast power feedback
parameters with energy production, which leads to corresponding changes in
the dynamics of the pulsed reactor. Comprehensive research to ensure safe
operation of the IBR-2M is required.
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2020-2 (1.706.780)
Brief Review of Topmost Scientific Results Obtained in 2019 at the Joint Institute for Nuclear Research
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P5-2020-1 (1.547.748)
Dikusar N. D.
A Three-Point Grid Based Polynomial Prediction
Within the framework of the recently proposed basic element method (BEM), a new approach is made to the solution
of the problem of polynomial prediction and extrapolation of the sixth order for smooth functions. The one step forward forecast
is performed using two fifth degree polynomials. The formulae for the coefficients of BEM-polynomials depend on the grid step,
the values of the function and its first derivative at the nodes of two three-point grids. The method was tested
on the numerical solution of the Cauchy problem for ODE. The efficiency of numerical integration is ensured by a threefold
calculation of the right side of the equation and the O(h5) accuracy of the solution. The BEM-prediction can serve as the core
for the development and creation of effective algorithms for numerically solving Cauchy problems for ODEs, including stiff ones.
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