The Journal of Kharkov National University, Vol. 880,
Physical series "NUCLEI, PARTICLES, FIELDS", Issue 4/44/, 2009
| V.D. Sarana, N.S. Lutsay, N.A. Shlyahov
Nuclear reactions induced by 3Íå on 19F nucleus at low energies (Rus.)
| N.V. Krupina, A.Yu. Korchin
Mechanisms of heavy quarks production in proton-proton collisions at high energies (Rus.)
| Yu.A. Kasatkin, A.P. Korzh
Additional terms for description of nonlocal interactions in QED (Rus.)
| V.A. Tsymbal, N.D.Masalitin, S.A. Pismenetskiy, V.G. Rudychev, Y.V. Rudychev, A.F.Stoyanov
Optimization of the target arrangement for the neutron source for the best producing 99Ìî (Rus.)
| A.N. Dovbnja, V.A. Tsymbal, N.D. Masalitin, S.A. Pismenetskiy, A.F. Stoyanov, D.Y. Shahov
The contribution of resonant neutrons to molybdenum activation in the neutron generator (Rus.)
| A.N. Dovbnya, S.S. Kandybei, V.I. Kirischuk, Yu.N. Ranyuk, V.M. Azhazha, K.V. Kovtun, M.P. Starolat
Triggering of long-lived isomer 178m2Hf by 50 keV electron irradiation (Rus.)
| V.I. Trotsenko, N.I. Mocheschnikov, V.Å. Ivashchenko
Simulation of signals of magnetic induction sensors and monitors of charged particle beams (Rus.)
| V.A. Lisovskiy, N.D. Kharchenko, R.N. Fateev
Normal mode of the DC discharge in low pressure nitrogen (Rus.)
| N.P. Dikiy, E.P. Medvedeva, I.D. Fedorets, N.P. Khlapova, N.S. Lutsay, Yu.V. Lyashko, D.V. Medvedev, A.P. Gavrik
Thermomodification of nanopowder natural clinoptilolite (Rus.)
| V.V. Ruzhytskyi, S.O. Karpov, V.O. Sanik, G.D. Tolstolutska, V.M. Voyevodin
Temperature intervals of helium and hydrogen retention in ferritic-martensitic steels EI-852 and EP-450 (Ukr.)
| Yu.V. Kovtun, E.I. Skibenko, A.I. Skibenko, V.B. Yuferov
Determination of effective rate of electron-impact ionization of multicomponent gaz- and gaz-vapor mixtures (Rus.)
| V.G. Kirichenko, E.S. Melnikova
The features of structure of nanometric graphite surface layers (Rus.)
| A.V. Samoylov, A.A. Zavgorodniy, R.V. Vovk, M.A. Obolenskii, K.A. Kotvitskaya, V.Yu. Gres’
Effect of doping by prazeodimom on temperature dependence of pseudogap in Y1-ZPRZBa2Cu3O7-δ single crystals (Ukr.)
| V.N. Lyashchenko, F.I. Ozherel'ev, S.N. Reva, D.A. Tsibliev
Synchronization system for experiments research installation "URAGAN-2Ì" (Rus.)
NUCLEAR REACTIONS INDUCED BY 3HE ON 19F NUCLEUS AT LOW ENERGIES
V.D. Sarana, N.S. Lutsay, N.A. Shlyahov
Full Text : (3170 kB, Rus.)
This work deal with experimental investigation cross sections of the elastic scattering 3Íå on 19F and nuclear reactions 19F (3Íå,ð) 21Ne and 19F (3Íå,α)18F with energies between 2.3 and 4,2 MeV. Excitation functions and angular distributions for transitions to ground and first two excite states of 21Ne and to ground, 5, 6, 7 excite states of 18F are measured. From a fluctuation analysis and comparison of experimental cross sections with expected on the theory of Hauser-Feshbach upper Ãexp = 135 ± 23 êeV and lower Ãåxp = 70 êeV limits of values of widths levels of compound nucleus 22Na at energy excitation 21 MeV are deduced, correspondingly. Rough estimations of form of the angular distributions of cross section in the framework DWBA, show that, if there is a direct single-stage transition of np-pair of nucleons, then it takes place transitions with the transfers of mainly next orbital angular
momentum - in transition to the ground-state of (3/2+) - L = 2, to the 1-th excited states of (5/2+ or with one L = 2, or with L = 2 + 4 and with L = 4 for transfer to the 2-th excited states (7/2+). In view of the strong contribution of compound nucleus mechanism, for legality of these values L are required experiments with more high energies.
KEY WORDS: nuclear reactions with 3-helium, nucleus-target are a fluorine, transitions to the 18-fluorine and 21-neon, cross sections, excitation function, angular distribution, mechanism of reaction, theory
of Hauser-Feshbach, distorted waves method.
OPTIMIZATION OF THE TARGET ARRANGEMENT FOR THE NEUTRON SOURCE FOR THE BEST PRODUCING 99MO
V.A. Tsymbal, N.D.Masalitin, S.A. Pismenetskiy, V.G. Rudychev, Y.V. Rudychev, A.F.Stoyanov
Full Text : (780 kB, Rus.)
With computer simulation using a version of the target structure has been analyzed for the Be(d,n) neutron generator aimed to produce 99Mo along the reaction 98Mo(n,γ)99Mo. It was shown
the biggest neutron density and the needed transformation of their spectrum in the limited volume the beryllium moderator can provide, which in addition realizes the neutrons multiplication in (n,2n) reaction. The parameters of polyethylene and beryllium moderators have been compared. The technique is proposed for the determination of the geometrical point and the form of the
irradiated spacemen for the maximal producing of 99Mo. The calculations have been executed with MCNP code on the base of geometrical model of the target arrangement. Absolute values of 99Mo output have been determined and were compared from analytic and digital estimations.
KEY WORDS: Monte-Carlo simulation, target for neutron generator, neutron moderation, beryllium, polyethylene, output of radioactive molybdenum, optimization.
THE CONTRIBUTION OF RESONANT NEUTRONS TO MOLYBDENUM ACTIVATION IN THE NEUTRON GENERATOR
A.N. Dovbnja, V.A. Tsymbal, N.D. Masalitin, S.A. Pismenetskiy, A.F. Stoyanov, D.Y. Shahov
Full Text : (490 kB, Rus.)
Interaction of the neutrons created by neutron Be (d, n) - generator and special target device from beryllium , with the sample from molybdenum is considered. Quantitative estimations are
executed on the basis of the decision of the equation of age for a dot source of fast neutrons, energy and sections of resonances of radiating capture by molybdenum. Influence of temperature of the Mo-target on the form of resonances (Doppler broadening) is considered. On the basis of calculations the contribution of resonant neutrons to a full exit (n,γ) reactions on
98Ìî which in the considered conditions makes about 35 % is estimated. Such influence of resonant neutrons is caused by dependence (n,γ) - sections 98Ìî from energy, and the spectrum
of neutrons formed by massive Be-moderator from fast neutrons.
KEY WORDS: the generator of neutrons, a target- moderator, beryllium, radiating capture, the contribution of resonances, the age equation, broadening of resonances.
TRIGGERING OF LONG-LIVED ISOMER 178M2HF BY 50 KEV ELECTRON IRRADIATION
A.N. Dovbnya, S.S. Kandybei, V.I. Kirischuk, Yu.N. Ranyuk, V.M. Azhazha, K.V. Kovtun, M.P. Starolat
Full Text : (1500 kB, Rus.)
The results of experiments on long-lived isomer 178M2Hf (T1/2 = 31 y) triggering when an isomeric target produced by 1.2 GeV Kharkov linear electron accelerator about 30 years ago has been irradiated at the electron microscope by 50 keV electrons are presented. It is shown that at low electron currents 178M2Hf isomer triggering is not observed. At the same time, when the currents have been increased by more than an order of magnitude, there are apparent effects indicating indirectly the possible triggering. In addition, conducted experiments clearly demonstrated that the existing measurement geometry cannot allow registering adequately the investigated phenomenon and requires substantial improvements.
KEY WORDS: 178M2Hf isomer, electron beam, HPGe detector, triggering, NEET process, quantum Zeno effect
THERMOMODIFICATION OF NANOPOWDER NATURAL CLINOPTILOLITE
N.P. Dikiy, E.P. Medvedeva, I.D. Fedorets, N.P. Khlapova, N.S. Lutsay, Yu.V. Lyashko, D.V. Medvedev, A.P. Gavrik
Full Text : (680 kB, Rus.)
Methods of gamma activation analysis, X-ray diffraction analysis and Ik-spectroscopy study element composition, crystallinity and character of an intermolecular interaction in samples of
a natural and thermomodified nanoklinoptilolite. In received klinoptilolite ? - spectrum observed γ - the lines matching to radionuclides 40K and from families 238U, 235U, 232Th. On intensity
of spectrum lines estimates of content Th and U are executed and is shown that their concentration in a klinoptilolite (Th - 1.06•10-5 and U - 2.75•10-6 ã/ã) approximately coincides with
abundance of these devices in earth crust. By results of radiographic and IR-spectroscopic examinations it is positioned that in the modified samples the high level of crystallinity and
klinoptilolite phases is conserved. Minor alterations intesity of lines of the diffraction reflexions 2θ = 9,93° and 26,60° and conversion of absorption bands of hydroxyl groups (OÍ, Si-
OÍ, K- OÍ and Nà-ÎÍ) testify to reorganisation in the vodno-cationic subsystem of a klinoptilolite which are not mentioning its basic alumosilicic carcase.
KEY WORDS: nanoklinoptilolite, gamma - activation analysis, X-ray diffraction analysis, IR-spectroscopy, thermoprocessing, crystallinity.
DETERMINATION OF EFFECTIVE RATE OF ELECTRON-IMPACT IONIZATION OF MULTICOMPONENT GAZ- AND GAZ-VAPOR MIXTURES
Yu.V. Kovtun, E.I. Skibenko, A.I. Skibenko, V.B. Yuferov
Full Text : (605 kB, Rus.)
The paper describes a simple method for determination of effective rates of gas and gas-vapor mixtures by the electron impact. The media investigated were the following mixtures: H2+ Ti, Ar+Ti, Kr+Xe+N2+O2, (Kr+Xe+N2+O2)+Ti. The experiments on the ionization of these media were carried out using the plasma of a pulsed reflecting discharge. A Ti concentration in
the discharge was varying within 0-50%. A comparison between the calculated values of the effective rate of multicomponent gas-vapor mixture ionization with experimental data is
KEY WORDS: ionization, elementary process, electron impact, multicomponent mixture, impurity concentration, electron temperature
EFFECT OF DOPING BY PRAZEODIMOM ON TEMPERATURE DEPENDENCE OF PSEUDOGAP IN Y1-ZPRZBa2Cu3O7-δ SINGLE CRYSTALS
A.V. Samoylov, A.A. Zavgorodniy, R.V. Vovk, M.A. Obolenskii, K.A. Kotvitskaya, V.Yu. Gres’
Full Text : (700 kB, Ukr.)
In present work we have investigated the conductivity in the basis plane of the doped by Pr and of YBaCuO single crystals. It is shown, that the excess conductivity for the analyzed samples
shows dependence Δσ~(1-Ò/Ò*)exp(Δ*ab/T) in a wide temperature range Tf < Ò < T*, where Ò* is the mean field temperature of superconducting transition. The temperature dependence of the pseudogap can be satisfactorily described in terms of the BCS-BEC crossover theoretical model.
KEY WORDS: excess conductivity, doping, YÂaCuO single crystals, high temperature superconductivity, crossover, pseudogap state.
SYNCHRONIZATION SYSTEM FOR EXPERIMENTS RESEARCH INSTALLATION "URAGAN-2Ì"
V.N. Lyashchenko, F.I. Ozherel'ev, S.N. Reva, D.A. Tsibliev
Full Text : (840 kB, Rus.)
A system of synchronizing the operation of technology systems, diagnostic equipment and instrumentation for carrying out physical experiments in plasma physics and controlled
thermonuclear fusion (CTF) on a major research facility "Uragan-2Ì" (Institute of Plasma Physics, NSC KIPT, Kharkov) are considered. The system is assembled on the basis of modules
in the CAMAC standard. It comprises a CC02 controller crate, MC01 launcher and six modules MD01 of programmable timers. Synchronization System is connected to a personal
computer using a galvanically isolated serial communication channel operating at data rates 10 Mbaud. Adapter for serial communication with the controller is installed in the computer on
the bus PCI and manages crate, which can be removed from the computer to a distance of 300 meters.
KEY WORDS: plasma, torsatron, computer, synchronizing, CAMAC, software