|
|
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.
| 2026 |
P13-2026-22 (408.745)
Verhoglyadova V.N., Verhoglyadov A. E., Shabalin E. P.
Three-Component Model of the Power Feedback of the IBR-2M Reactor
The paper proposes a model of power feedback of the pulsed reactor
IBR-2M, constructed in terms of automatic control theory based on three known physical feedback effects. From the differential equations of thermal
conductivity, the impulse transition characteristic of feedback is obtained. The model calculations of IBR-2M dynamics correspond to experimental data.
The prospects of application of the model for analysis of the dynamics of the pulsed reactor are discussed.
|
P13-2026-20 (581.601)
Verhoglyadov A. E.
Study of the Influence of Coolant Flow on Transverse Vibrations of a Fuel Rod of a Pulsed Reactor
The work presents an experimental study of transverse vibrations of a model
fuel rod of the IBR-2 reactor in a liquid flow. The influence of the direction and
velocity of the fluid, as well as the method of fixing the fuel rod on its natural
frequencies, damping decrement and oscillation amplitude in a turbulent flow
is investigated. The obtained results are necessary for constructing a model of
the dynamics of a periodic pulsed reactor and developing the design of a new
neutron source.
|
E7-2026-18 (2.620.875)
Isaev A.V. et al.
Average Number of Prompt Neutrons in the Spontaneous
Fission of 260Rf
An experimental study of 260Rf produced in the complete fusion reaction
238U+26Mg was performed using the SHELS velocity filter. The prompt neutron multiplicity in the spontaneous fission of 260Rf was measured for the first time,
yielding an average value ν‾(260Rf) = 4.88 ± 0.24. The half-life was measured as T1/2 (260Rf) = +5.5-3.8 ms (95% CL).
|
P1-2026-16 (1.001.703)
Komarov V. I.
M. G. Meshcheryakov — Founder of a New Scientific Direction
M. G. Meshcheryakov is widely known as the creator of the first Dubna
accelerator, the proton synchrocyclotron, and the organizer and head of the
Laboratory of Computing Techniques and Automation at JINR. However, he
is less known as a physicist who opened a new direction in the research
of nuclear physics and elementary particles — short-range nucleon–nucleon
and nucleon–nucleus interactions. This publication discusses the pioneering
experiments performed and carried out by M. G. Meshcheryakov, and the further
development of this direction, mainly based on the example of work carried out
at JINR.
|
P18-2026-12 (421.594)
Kaplina S. P. et al.
Assessment of the Content of Rare Earth Elements, Thorium and
Uranium in Coals and Ashes from Different Deposits in Mongolia
The content of rare earth elements (REEs), thorium and uranium in the
coals and coal ashes of the Baganuur, Shivee-Ovoo, and Bayanbogd deposits
was studied using current analytical methods: inductively coupled plasma mass
spectrometry, X-ray fluorescence, and gamma activation analysis. A geochemical
assessment of the concentrations of the studied elements was carried out.
The coals of the studied deposits are enriched with light lanthanides. Correlations
between the content of REEs and thorium, as well as uranium, have been
established. A primary assessment of the resource potential of the contained
REEs was carried out, an assessment using the perspective coefficient (Kper),
which showed that the ash of coal from the studied deposits can be considered
as a promising source for obtaining REEs. It has been shown that when coal
is burned at the Ulaanbaatar Thermal Power Plant-4, REEs are concentrated in
various ash fractions (slag and fly ash). The enrichment of ash and slag waste
with REEs such as Sc, Y, La, Ce, and Nd is 2.6–9.7 times higher than that of
the original coal.
|
P19-2026-6 (721. 554)
Agapov A.V. et al.
Comparison of the Frequency of Micronucleus Induction in A 549 Cells under the Action of X-Ray and Gamma Radiation
Experiments were carried out to obtain calibration curves of micronucleus induction in the A 549 cells depending on the dose of X-ray radiation at the
SARRP facility of the JINR Laboratory of Radiation Biology and to compare the results with previously obtained dose dependences at the “Rokus-M” gammatherapeutic
facility with the 60Co radioactive source. The possible reasons for the differences in the results obtained at the two installations are analyzed.
|
P3-2026-5 (3.973.377)
Enik T. L. et al.
Direct Beam Boron Detector for Monitoring and Analyzing the Neutron Spectrum at the YuMO Small-Angle Spectrometer of the IBR-2 Reactor
This article discusses the direct beam detector of the YuMO spectrometer
(IBR-2, FLNP). Optimization and measurement results using a gas proportional
multiwire direct beam detector with a boron converter (10B4C) are presented.
Spectra obtained after a recent upgrade of this detector (converter replacement,
voltage optimization, etc.) are described.
The forward beam detector is used to measure the spectrum of neutrons
passing through a sample (obtaining the sample transmission function as a
function of neutron wavelength), as well as to adjust the collimation system and
the chopper operating window (synchronizing the chopper window closure to
suppress background neutrons). The detector is also used for data normalization
in measurements with samples having a high scattering or absorption crosssection.
As a result of the upgrade, the detector count rate has at least doubled. It is
shown that the neutron beam on the YuMO spectrometer is well collimated, the
detector is aligned, and the correct chopper phase is selected.
|
E7-2026-3 (1.414)
Isaev A.V. et al.
Prompt Neutron Emission in the Spontaneous Fission of 258,260Sg
An experimental study of 258,260Sg produced in the complete fusion reactions 207Pb + 52,54Cr was performed using the SHELS velocity filter.
Prompt neutron multiplicities in the spontaneous fission of 258,260Sg were measured for the first time, yielding average values of ν¯ (258Sg) = 4.9 ± 0.4 and ν¯ (260Sg) = 5.03 ± 0.14.
The α-decay branching ratio of 260Sg was determined to be bα = 0.29 ± 0.03. In addition, the half-lives were measured as T1/2(258Sg) = 2.2+2.4-1.0 ms (95% C.L., confidence limit)
and T1/2(260Sg) = 7.0+2,6-1.7 ms (95% C.L.).
|
P3-2026-2 (4.777.234)
Aksenov V. L. et al.
Fast Pulsed Reactors
In 1960, the world’s first fast pulsed nuclear reactor IBR was created
at the JINR. The second-generation reactor IBR-2 has been in operation
since 1984. An analysis of the distinctive characteristics of the IBR type reactors
is presented, the main one of which is related to the instabilities of power
fluctuations. A description of the conceptual design of a third-generation reactor
NEPTUN is proposed, which solves the problem of instabilities and opens up
new possibilities for neutron beam research.
|
|
|
