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| 2023 |
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P13-2023-64 (698.255)
Pepelyshev Yu. N., Sumkhuu D.
Influence of an Automatic Power Control System of the
IBR-2M Pulsed Reactor on Its Dynamics
New optimal values of the parameters of the automatic power
control (AC) system were obtained by modeling and experimentally using the
mathematical model of the IBR-2M dynamics, taking into account the
real parameters of the fast power feedback. Optimality in this case is the
ability of the AC system to reduce reactor noise in general and especially
its low-frequency component. Two variants of operation of a statistically
optimal automatic controller are considered. For the operating AC variant,
which uses data averaging with information aging, it can be seen
that the parameters of the power transition process strongly depend on the
value of the smoothing coefficient q. With increasing q, the quality of the
transient process deteriorates, and the resonant lines in the low-frequency
oscillations of the pulse energy grow. For the second variant of the
statistically optimal AC with a constant information value of the controlled
parameter N, calculations show that the optimal value of the coefficient
N is in a fairly narrow range (4—8), neither higher nor lower.
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P13-2023-63 (2.512.991)
Krupko S. A. et al.
Design and Performance of the Fragment Separator ACCULINNA-2
The paper observes
A systematic discussion is given of the design of all key subsystems of the ACCULINNA-2 facility: components
of the primary beam line and beam diagnostics, producing target, primary beam absorber, equipment for transport, cleaning
and diagnostics of the secondary beam, RF-filter for additional beam cleaning, cryogenic physical target, forward
spectrometer, automated control system. The
%paper presents
characteristics of the secondary beam are presented: angular and spatial
distribution in the final focus, identification quality of ions by Δ E—ToF diagram and output of the desired isotopes
at the settings to multiple energies, obtained during the experiments in 2018—2020 on primary beams of 11B, 15N, 32
when set to secondary beams of8He, 9Li, 11Li, 10Be, 27S è 26P.
Comparison with calculations of secondary beam transport has been performed. There is a possibility to carry
out experiments with light exotic ions at high accuracy of detection and measurement of the parameters of the incident ion
on condensed hydrogen and helium targets.
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E7-2023-61 (309.792)
Mukhin R. S. et al.
The Search for Spontaneous Fission from the 250No Isomeric State via Prompt Neutron Multiplicity Distribution Analysis
The complete fusion reaction 204Pb(48Ca, 2n)250No was used to study two activities of 250No
with distinct half-lives. A total of 1357 events were observed in the SFiNx neutron detection system. The study aimed to differentiate
prompt neutron multiplicity distributions of 250No for the ground and the K-isomeric states.
However, the distributions for both activities were indistinguishable according to statistical tests.
The average number of neutrons emitted per spontaneous fission of 250No was determined to be 4.1 ± 0.1. Using the Tikhonov regularization method,
a prompt multiplicity distribution was presented for the first time. Despite significant efforts, numerous questions about the 250No isotope remain,
emphasizing the need for continued research.
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P5-2023-54 (138.132)
Yamaleev R. M.
Evolution Equations of Higher Order Kinematics
The path length traveled by an accelerated body with constant acceleration is described by the polynomial
of second degree in time. In this work, we develop a generalized kinematics, where the distance, velocity, acceleration
and higher order accelerations are determined by the higher degree polynomials.
The evolution equations derived in this scheme are cast into the triangular-like systems and form the Appell
sequences of polynomials admitting the Pascal-matrix representation. By making use of the mathematical tool developed
with respect to the higher order kinematics, the evolution equations for the extended classical mechanics are derived.
It is shown that the relativistic mechanics and extensions of the classical mechanics are naturally cast into the frames of the elaborated mathematical tool.
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P11-2023-52 (293.970)
Amirkhanov I. V., Sarkhadov I., Tukhliev Z. K.
Numerical Results of Thermal Processes Occurring in Materials under the Action of Femtosecond Laser Pulses
In recent years, lasers have been created that generate ultrashort light pulses.
Currently, there is an increasing need to create and improve reliable physical models capable of describing various processes in matter.
At the same time, computer modeling now occupies one of the main places in the study of such problems.
The paper proposes a modification of the thermal spike model based on a system of two coupled hyperbolic heat conduction equations for an electron gas and a crystal
lattice for modeling thermal processes occurring in materials under the action of femtosecond laser pulses. The action of the laser in the electron gas is taken
into account through the source function.
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P11-2023-51 (293.970)
Amirkhanov I. V. et al.
Simulation of Laser Ablation of Materials within the Thermal Spike Model
In previous works, numerical simulations of laser ablation of materials arising under the action
of ultrashort laser pulses in semi-bounded samples and samples of finite thickness were carried out within the framework of the thermal conductivity equation.
In this paper, a similar simulation is carried out for semi-bounded samples in the framework of a two-temperature thermal spike model, which consists of two
interrelated heat conduction equations for an electron gas and a crystal lattice. The laser action is taken into account through the source functions in the equation
of thermal conductivity of the electron gas, setting the coordinate and time dependences of the laser source. A comparative analysis of the obtained results of the two models is made.
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P9-2023-50 (9.423.102)
Semyonov V. N. et al.
Ion Beam Positioning and Position Stabilization System for EG-5
Accelerator
As part of the project of modernization of the EG-5 accelerator, the authors
of the report, based on 4 current sensors and an electromagnetic deflection
system, developed an automated system for positioning and stabilizing the
position of the ion beam (ASPSIB) in the ion pipe of the electrostatic
accelerator (ESA) EG-5.
Calculations, modeling of processes in electrical circuits, and tests on an
optical model were carried out.
The principle of operation of the system, main elements, modeling results
and proposals for the development of this option are considered.
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P18-2023-47 (63.010.639)
Shabalin A. D.
Influence of Ionizing Radiation on Frond Morphology of Some Fern Species
The present study is aimed at detecting and monitoring the ongoing
mutational morphological changes of four species of pteridoflora (Athyrium filix-femina, Dryopteris dilatata, Gymnocarpium dryopteris and Phegopteris connectilis)
of the Dubna urban district in a natural forest growing environment
during an experiment on irradiating these plants with gamma rays on the 3rd
channel of the IBR-2M reactor of the Laboratory of Neutron Physics of the
Joint Institute for Nuclear Research. In the course of the study,
photographs of morphological changes in the structure of fronds were
obtained relative to control samples that were not subject to irradiation,
and conclusions were drawn regarding the effect of gamma irradiation on the
pteridoflora of the urban district of Dubna.
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P4-2023-41 (201.273)
Kuz'min V. A., Tetereva T. V.
Ordinary Muon Capture by Cadmium Nuclei
The partial and total rates are calculated for the ordinary muon capture by even cadmium isotopes.
The theoretical rates are compared with experimental data. The theoretical total rates of muon capture agree with the experimental ones well.
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Ð1-2023-39 (8.974.601)
Komarov V. I.
Memories of Bruno Pontecorvo
The notes describe the communication of a researcher V. I. Komarov at the Laboratory of nuclear problems with an outstanding physicist of the twentieth century,
Bruno Pontecorvo. The memory of work and friendly relations allows to see features of a portrait of an outstanding scientist at the angle of his relationship with ordinary people.
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P13-2023-35 (790.678)
Agapov A. V. et al.
Delivery of High-Intensity Proton Beam for the Study of Flash Effect in Radiotherapy
Flash therapy is a rapidly developing field of radiology that has the potential
to revolutionize future cancer treatment techniques. The method involves delivery of the therapeutic radiation
dose to the tumor volume at an ultra-high dose rate in the beam, several orders of magnitude higher than that
usually used in conventional radiotherapy. In this mode of irradiation, the degree of damage to normal tissues
surrounding the tumor and falling under the influence of radiation decreases, at the same time, the effect on
cancer cells remains at the same level, which preserves the prospect of local control of the tumor with a lower frequency of side effects.
The paper presents the results on the delivery of a high-intensity proton beam with an energy of 660 MeV from the Phasotron of JINR (Dubna),
designed for radiobiological studies under flash-therapy irradiation of cell cultures and small laboratory animals (mice, rats).
In addition, the main design features and parameters of the created detectors for measuring the characteristics of this beam are presented.
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E11-2023-37 (2.645.236)
Chervyakov A. M.
On Finite-Element Modeling of Large-Scale Magnetization Problems with
Combined Magnetic Vector and Scalar Potentials
A numerical performance of finite-element modeling based on the combination of magnetic vector and total scalar
potentials is assessed against the vector potential formulation for two magnetization problems, the Helmholtz coil and the dipole magnet.
The potentials are applied to conducting and nonconducting parts of the problem domain and coupled together across their common interfacing boundary.
Thin cuts are constructed in the current-free regions to ensure the consistency of the formulation. Simulation results show a substantial reduction in the computational
cost provided by the mixed formulation compared to its vector counterpart for a similar accuracy of both methods.
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P13-2023-34 (298.980)
Agapov A. V., Mytsin G. V., Shipulin K. N.
Development of Ionization Chambers for Monitoring High-Intensity Radiation Beams
In the Medical-Technical Complex of the DLNP JINR, two air ionization
chambers were developed and tested as part of a research project exploring
the «Flash effect» caused by a proton beam with an ultra-high dose rate on
biological objects. The first chamber, a monitor parallel-plane chamber with
an ultrathin gap, has a narrow interelectrode air gap of only 0.5 mm which
ensures efficient charge collection and no recombination during measurements
of high-intensity pulsed (with a duty cycle of 100) proton beams. The second
chamber features a parallel-plane monitor chamber for dose delivery
monitoring and a multi-pixel ionization chamber for beam spatial
characteristic control. Electronic components and software were also
developed for the cameras. Tests demonstrated the chambers' full operability
when measuring high-intensity proton beam parameters from the JINR Phasotron.
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P19-2023-31 (227.167)
Rzyanina A. V. et al.
Research on Survival of À549 Tumor Cells under Proton Beam Irradiation in Flash and Conventional Mode
Flash radiotherapy is an innovative method of irradiation, which ensures the delivery of the therapeutic dose to the
pathological focus in a time of about several tens of milliseconds. In this mode of irradiation, the degree of damage to normal tissues
surrounding the tumor and falling under the influence of radiation decreases; at the same time, the effect on cancer cells remains almost
at the same level, which improves the prospect of local control of the tumor with a lower frequency of side effects. To date, the exact radiobiological
mechanisms underlying the flash effect are not fully clear.
The paper presents the results on the delivery of a high-intensity proton beam with an energy of 660 MeV from the Phasotron of JINR (Dubna)
designed for radiobiological studies under flash technique of irradiation of cell cultures and small laboratory animals (mice, rats).
The survival rate of A549 cells under proton beam irradiation in two modes, flash and standard, was also compared.
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E6-2023-29 (108.061)
Izosimov I. N.
Application of the Method of Moments for the Doublet and Triplet Analysis in the Radiation Spectra
When processing spectra, it is usually sufficient to
determine only the positions of the peaks and their areas. To use the method
of moments for doublet peaks analysis, it is necessary to first construct
(calibrate) the dependence of the second and third moments for single peaks
on the energy of the corresponding radiation. After such calibration
overlapping peaks can be separated. To separate peaks in doublet using the
method of moments, it is necessary to solve a quadratic equation. To
separate peaks in triplet, it is necessary to have appropriate calibration
curves already up to the fifth moment inclusive and solve a cubic equation.
Examples of the separation of overlapping peaks in the analysis of gamma-ray
spectra are presented.
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P13-2023-28 (1.527.321)
Nikitenko Yu. V.
Accumulator of Cold and Very Cold Neutrons
Circle mirror accumulator of cold and very cold neutrons for neutron source
is proposed. The relations are obtained for calculating of accumulator
parameters, neutron current density and hold time. It is shown the gain
factors for current density and hold time can achieve a hundred. Some
possibilities of creating and using an accumulator in physical investigations
are considered.
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P10-2023-27 (253.368)
Morkovnikov I. A., Truntova L. A.
PyChannel Messaging Service in Sonix+
We consider the development of the PyChannel messaging service for the Sonix+ software package,
which provides control of the measuring facilities at the IBR-2 reactor at FLNP JINR.
The need for this was determined by the fact that the current implementation of the inter-module communication protocol based on the
Varman database cannot provide data exchange between modules running on different computers and servers with different operating systems,
as well as the interaction of 64-bit and 32-bit programs.
The article describes the adaptation of PyChannel to the needs of different programs that are part of the software package in order
to create a unified service to extend the capabilities of Sonix+.
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P16-2023-24 (1.837.880)
Mokrov Yu.V. et al.
Experimental Research of the Response of the Albedo Individual Neutron
Dosimeter DVGN-01 in the Field of the Accelerator DC-280 to Correct Its
Readings
The paper presents the results of an experimental research of the response
of albedo individual neutron dosimeters DVGN-01 of the AKIDK-301 and AKIDK-302 complexes in
order to correct their readings.
Correction of the DVGN-01 readings was carried out using correction
coefficients, which were determined by the results of measurements using a spherical albedo system when it was irradiated at eight points on the DC-280
accelerator: in the accelerator hall near the radiation monitor and in front
of the protective door from the accelerator hall, in the beam output cabins
(rooms 113 and 115) and in a permanent staff room on the second floor near
the accelerator. The obtained values of the coefficients are in good
agreement with the coefficients obtained earlier on the FLNR accelerators
and currently used in individual dosimetric control of laboratory personnel.
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P1-2023-22 (2.405.634)
Belyaev A. V.
Finding the Mass of a Charged Particle According to the Shape of Its Trajectory, and Hypothesis of Anomalous Lepton Existence Test
According to the current state of the theory of particle physics, the number of generations of leptons (and quarks) is three.
In this case, however, the mass distribution of the three known leptons is such (me ∼ 100, mμ ∼ 102,
mτ ∼ 103 MeV/c2)
that the hypothesis of the possible existence of a fourth anomalous lepton with a mass ma ∼ 101 MeV/c2 often arises.
Such a large difference in
the masses of leptons is not fully explained at present.
In this paper, we directly test the hypothesis of the existence of a lepton with a mass ma ∼ 101 MeV/c2.
Thus, a method is proposed for finding the mass of a charged particle by the spatial trace (track) left by it, passing through matter in a uniform magnetic
field near the stopping point. In the projection of the spatial track onto a plane perpendicular to the direction of the field, the particle trajectory is
approximated by a helix («hadroide»), one of whose parameters is proportional to the particle mass. The initial energy of the particle does not matter for this problem.
In accordance with the method, the mass of the particle is found.
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P10-2023-21 (350.755)
Belyaev A. V., Rikhvitsky V. S.
Kinematic Fitting in the Restored Film Information Processing (FIP) in Pictures from Bubble Chambers
The VisualGeoKinFit procedure for kinematic fitting as part of the
reconstructed film information processing on photographs of bubble
chambers is presented. Photographs of 1-meter hydrogen and 2-meter propane
chambers, which were obtained in the measurement sessions of the 60s—90s of
the 20th century at JINR, are considered.
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P1-2023-20 (278.002)
Rikhvitsky V. S., Belyaev A. V.
Polynomial Approximation of the Magnetic Field for Track Detector
The magnetic field of the 1-meter hydrogen bubble chamber at LHE JINR was measured in 1971.
In the programs for the geometric reconstruction of physical events, these data were used to calculate the field at arbitrary points in space using linear interpolation methods.
It is convenient to approximate the measured magnetic field by polynomials, which makes it possible to exploit the connections imposed by the magnetic field equations.
The method of least squares is used to construct basic polynomials that satisfy the Laplace equation. The proposed method for constructing the basis was
implemented and used in a number of programs for processing experimental data obtained on track detectors.
The presented method can be applied not only to bubble chambers, where the field is stationary and close to uniform, but also to other track detectors.
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P10-2023-19 (556.856)
Belyaev A. V., Rikhvitsky V. S.
Refinement of Optical Constants for Bubble Chambers
At JINR, on the new software and hardware complex, the film information
processing (FIP) for bubble chambers (1-meter hydrogen and 2-meter propane)
was restored, which was obtained in the measurement sessions of the 60—90s
of the 20th century at JINR. During the restoration, inaccuracies were found
in the spatial reconstruction of the points. A minimization algorithm has
been found that refines the «optical constants» of photographic lenses and
their location in the common Cartesian coordinate system of cameras.
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P10-2023-18 (2.096.993)
Baldin A. A. et al.
Recovery of the Software and Hardware Complex for Film Information Processing (FIP) for Bubble Chambers
The complex for film information processing (FIP) obtained on bubble chambers has been restored.
A procedure for the geometric reconstruction of spatial coordinates obtained from measurements on photographs of bubble chambers is presented.
This procedure is a significant modification of the previous one. The work of the FIP is demonstrated in the photographs of the 1-meter hydrogen and 2-meter propane chambers,
which were obtained during the measurement sessions of 1960-2000 at JINR.
The reconstructed FIP complex adequately corresponds to, and in some ways even surpasses, the previously existing complex in the main parameters: spatial resolution and processing speed.
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P10-2023-14 (1.590.162)
Kirilov A. S. et al.
Reorganization of the Sonix+ Software Package to Work with Data in the Event List Form
In the coming years the application of new DAQ controllers in which there is no hardware data histogramming
will become more and more widespread at the IBR-2 instruments. At the same time, the primary data presentation in the histogram
form is replaced in favor of accumulation in the form of a list of individual events, which corresponds to the global trend.
This will entail a certain restructuring of the Sonix+ complex. Thus, on the one hand, histograms should be kept for operative
visualization, as well as for data reduction programs, which are specific for each instrument. On the other hand, the hardware sampling
limitation in the construction of these histograms is removed, which is expected to lead to a significant increase in histogram size,
including exceeding the limit of available virtual address space for 32-bit applications in practice.
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P13-2023-13 (721.699)
Butusov I. V. et al.
Stabilized Gas Installation for Filling Charged Particle Detection Systems
A setting has been worked out for filling various systems with gas, from gas
detectors of ionized radiation to vacuum chambers of magnetic analyzers and
separators. The setting meets all the necessary conditions for filling these
systems: high stability in pressure, gas flow and temperature. The described
system is successfully used in detectors and settings of the Flerov
Laboratory of Nuclear Reactions.
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E13-2023-12 (243.191)
Gapienko I. V. et al.
Research and Development of the Polarized Deuteron Source for the Electrostatic Accelerator
The prototype of a polarized deuteron source was made for the Van de Graaff accelerator of the Czech Technical University in Prague
with the aim of creating a full-scale setup for producing
a polarized neutron beam for experiments on measuring ΔσL and ΔσT, longitudinal and transverse spin asymmetries
in transmission of a polarized neutron beam through a frozen polarized deuteron target. The method is based on Kaminsky's experiment on channeling
deuterons through a magnetized single-crystal Ni foil 1-2 μm thick.
It is proposed to use the reaction T(d,n)4He with polarized deuterons of an energy of 150-200 keV.
For a nonchanneled beam (the goniometer in a random position),
the tensor polarization measurements were carried out with a TiT target.
Our result is Pzz=-0.10±0.02.
This indicates that the deuterium atoms that have passed outside the channels also become polarized due to the capture of polarized electrons from the nickel crystal.
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E10-2023-11 (535.814)
Lenivenko V., Palichik V., Patsyuk M.
Reconstruction of Simulated and Experimental Data in Coordinate Detector Systems Upstream of the Analyzing Magnet of SRC at BM@N Experiment in 2018
Multiwire proportional chambers and silicon detectors
were located upstream of the analyzing magnet at the SRC at BM@N setup
during the 2018 measurement. The reconstruction for these coordinate
detectors was developed for both simulated and experimental data. The
developed algorithms were added to the official software. The reconstruction
results of the 2018 data were compared with the simulation. The main
characteristics of the coordinate detectors upstream of the dipole magnet were
evaluated and analyzed.
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P13-2023-10 (1.539.579)
Vovchenko E. D. et al.
Experimental Laser-Plasma Diode with Magnetic Insulation for Neutron Generation
The simulation results of a diode accelerator for generating neutrons using a laser source of deuterons and a
system for suppressing electronic conduction by magnetic fields are presented. Options of the formation of an insulating magnetic
field by ring permanent magnets and a spiral electrodynamic line are considered. The possibility of realizing an efficient pulsed
neutron generator based on such an accelerator is shown. The results obtained in numerical and physical experiments allow one to expect
the achievement of record values of the energy cost per one neutron yield using the nuclear reaction T(d,n)4 He.
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P9-2023-9 (2.974.825)
Baturitsky M. A. et al.
TESLA-Type Superconducting Accelerator Niobium Resonators for Electrons and Positrons
The monograph is devoted to the development and creation of prototypes of superconducting niobium resonators in which electromagnetic field energy is
transferred to accelerated charged particles. These studies were carried out as part of JINR's participation in the ILC project in accordance with the scientific
theme 02-0-1067-2007/2015 (Leader G. D. Shirkov) «Research in the field of e+e– linear accelerators and colliders of a new generation for fundamental and applied purposes».
For this purpose, Yu. A. Budagov organized the production of a working sample of a TESLA-type superconducting resonator from Fermilab (USA),
which was used as a reference and for setting up measuring equipment.
On the initiative of Yu. A. Budagov, work was organized in Minsk to create superconducting microwave resonators of this type by the
leading research organizations of the Republic of Belarus. A complete production cycle of manufacturing parts of superconducting niobium resonators was developed,
all the necessary technological equipment was created, and two resonators were manufactured. According to the test results, a Q factor of 1.5 · 109
was achieved on one of them.
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P13-2023-3 (686.737)
Perelygin V. V.
The CMS Muon System
The muon system of the CMS facility (CERN) is presented, which uses detectors of three types: drift tubes,
resistive plate chambers, and cathode-strip chambers. The characteristics of the muon system during the period of CMS data taking
with p—p collisions in 2016-2018 are given. Plans for the development of the muon system under the Phase II CMS upgrade project are presented.
The problems of replacing greenhouse gases used in CMS muon detectors with gases with a lower global warming potential are discussed.
The results of studying the effects of radiation aging of cathode-strip chambers at the GIF++ facility (CERN) are presented.
The possibility of CSC operation with a reduced content of CF4 in the working gas mixture is being investigated.
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