A.A. Burtsev , A.A. Krupennikov , Yu.V. Senatskiy
№ 2 Stored energy formation for pulsed selectivelypamped solid state lasers
Скачать препринт |Аннотация|
In connection with an elaboration of selective pumping techniques for solid-state laser-drivers a stored energy formation in solid state media under absorption of a narrow-band pumping radiation have been considered. The calculations demonstrate the possibility of the inversion profile smoothing in the slab-like active elements in the oase of a pumping from ecxited levels of activator’s ions. A possibility of the Nd:glass laser usage to carry out modelling experiments on selective pumping at the several kJ energy level is discussed.
---------------------------
Yu.A. Merkuliev , A.A. Akunets , V.S. Bushuev , V.M. Dorogotovtsev , A.I. Gromov , A.I. Isakov , A.I. Nikitenko , S.A. Startsev , S.M. Tolokonnikov , R.S. Cook
№ 4 Study of production and quality of large (1-2mm)polystyrene hollow microspheres Paper submitted to the meeting of material reserch society (USA) 1994
Скачать препринт |Аннотация|
We present a summary of the techniques used to produce hollow plastic microshells from solid polymer granules using drop tower techniques. Unlike solution drop tower techniques, the use of these granules allows one to produce good quality shells with diameters of 1 to 1.5 mm. The reasons for hol?low plastic shell diameter limitations are discussed, and based on these studies we present a new drop tower furnace concept we call a ballistic furnace that has been designed to produce large (2 to 3 mm) polystyrene shells. The characteristics of the individual components such as the pellet injector and the fast cooling system are given.
---------------------------
V.Yu. Nikulin , S.P. Tsybenko
№ 6 A simple model of Davydov-Zakharov class for plasmas in magnetic field: diskontinuous solutions
Скачать препринт |Аннотация|
A simple hydrodynamic plasma model, taking into account the electron vor-ticity effect on the plasma motion and magnetic field behaviour, is formu?lated in terms of Davydov-Zakharov formalism. The discontinuous solutions of model are obtained. It appears that the shock waves imply the plasma rarefaction
---------------------------
O.D. Dalkarov , V.M. Kolybasov , D.V. Voronov
№ 8 On the mechanism of nuclean reactions with — hypernuclear systems production
Скачать препринт |Аннотация|
It is shown that the data on the reaction 12С(К~,7Г+)Х in flight in the region of possible E-hypernuclei existence can be described in terms of quasi-free production and final states interaction of E-hyperon. To check this reaction mechanism it is necessary to investigate the mass distributions of X as a function of momentum transferred from K~ to тг*. The singularities of triangle diagrams, corresponding to the effects of final states E-hyperon interaction, lead to the existence of rather narrow moving peaks in these mass distributions. Also the predictions for (К-, IT*) reactions with 4He and 6Li nuclei are made.
---------------------------
I.S. Shapiro , A.V. Smirnov
№ 9 Relativistic potential-like approach to the nucleon-antinuccjeon system
Скачать препринт |Аннотация|
In terms of the quasipotential formalism on an invariant space-like surface a relativistic one boson exchange model is constructed, intended for appli?cation to the NN-system. The most important property of the approach constats m that it does not lead to ultraviolet divergences in scattering am?phtudes, arising in the nonrelativistic Lippman-Shwinger equation due to expansions of corresponding one boson exchange potentials in powers of v/c. This, in its turn, allows to avoid nonphysical regularization (cutoff) proce?dure, strongly affecting the results of calculations. The decomposition of the scattering amplitude in partial amphtudes is fulfilled and a system of rather simple coupled integral equations for the latters is written. A solution of this system in the pseudoscalar exchange model is found, demonstrating that relativistic effects may give rise to new phenomena in particle scattering.
---------------------------
V.F. Kovalev , S.V. Krivenko , V.V. Pustovalov
№ 13 Lie symmetry and a group on a solution of a boundary value problem
Скачать препринт |Аннотация|
Л method of construction of a group on a solution (renor ingroup) is suggested and realized for the linear parabol?ic equation. It is based on the group analysis of a basic differential equation and a differential constraint, that ex?plicitly takes into account boundary data. The algebra of infinitesimal renorrngroup operators is considered and an in?terpretation of these operators in terms of symmetry group generators of the basic equation is given. It is shown that the exact solution of a boundary value problem is contained in the invariant manifold corresponding to each of renorrn?group operators.
---------------------------
P.G. Kryukov
№ 17 A FREQUENCY-DOUBLED PULSED CHEMICAL OXYGEN-IODINE LASER AS AN EFFICIENT PUMP SOURCE FOR HIGH POWER SOLID-STATE LASERS
Скачать препринт
V.S. Zuev , A.v. Frantsesson
№ 20 Fundamental Eigenwaves in Waveguides of Multiply Connected Cross Section: Laser Light Concentration on an Area of Subwavelength Dimension
Скачать препринт |Аннотация|
Various applications of multiconnected waveguides for localizing and concentrating laser light onto areas of subwavelength transverse dimension are proposed and proved. In optical microscopes, this makes it possible to reach the subwavelength resolution along all three spatial coordinates. In experiments, where interaction of laser radiation with matter is studied, the subwavelength multiconnected waveguides allow the field intensity in the optical wave to be significantly increased Applications of subwavelength waveguides in submicrometer photolitograpy, nanotechnology of microelectronics, and for all-optical information recording and readout are discussed. The work is supported in part by RFBR and ISTC.
---------------------------
V.I. Bijakas
№ 21 SHAPE CONTROL AND KINEMATIC WAVES IN LARGE SPACE STATICALLY DETERMINATE STRUCTURES
Скачать препринт |Аннотация|
The new mechanical effect — kinematic waves, which arise in large statically determinate designs during static shape control — is discovered and described. Linear, axis- symmetri?cal and two-dimensional statically determinate controllable structu?res are considered. The existence of different types of kinematic waves is shown. Algorithms of shape control are proposed. Mathemati?cal model, which describes the surface distortion of space foldable mirror, caused by fixation errors during the deployment, has been built and studied.
---------------------------
N.S. Konovalova
№ 22 THE EMULSION CHAMBER THRASHOLD EFFECT IN COSMIC PARTICLE SPECTRA DETERMINATION
Скачать препринт |Аннотация|
The results of calculations carried out for the cosmic radiation nuclei registration in emulsion chambers of two types are presented. It is shown for the groups of nuclei with Z>1 that the lead emulsion chamber without additional target permits to reconstruct the primary cosmic particle spectrum more accurately than emulsion chamber with thick light target.
---------------------------
P.I. Arseyev , N.S. Maslova
№ 25 HUBBARD MODEL FOR INFINITE U: PECULIARITIES OF DIAGRAM TECHNIGUE FOR «SLAVE-BOSON» APPROACH
Скачать препринт |Аннотация|
We suggest temperature diagram technique for Hubbard model with infinite U based on «slave boson approach » with exact constraint on each site particle number. Such constraint results in specific features of diagrams, appearing in the theory : unlinked diagrams do not can?cel out and Dyson equation in the usual form does not exist. Mean field results appear in our method as the simplest approximation. Exact solution for two- site system is obtained as an example of cal?culations in the framework of the developed technique. For infinite lattice we have derived the set of selfconsistent equations different from mean field approximation. The appearance of new features in electron spectrum arid density of states modifying mean field results is qualitatively shown.
---------------------------
S.P. Tsybenko
№ 26 SHOCKS IN LASER PRODUCED PLASMAS: THE CRITICAL STEEPENING AND MAGNETIC FIELD GENERATION
Скачать препринт |Аннотация|
Here a simple model of Davydov-Zakharov class for laser produced plasmas is developed. The rarefaction shock waves related to this model include the critical steepening as well as the magnetic field generation. The corresponding current densities may reach values of the order 1 ?*4.
---------------------------
Ju.V. Korovkin , V.B. Rozanov , A.S. Shikanov , G.A. Vergunova
№ 27 THE MONOCHROMATIC X-RAY SOURCES WITH FREQUENCY TUNING FOR STUDYING NONSTATIONARY MICROOBJECTS
Скачать препринт |Аннотация|
The results of investigation of monochromatic X-ray source with frequency tuning are presented. The souroe is developed on the basis of vaouum diode with a laser-plasma oathode. The proposed source is especially promising for progressing into the area of X-ray > 5 keV. The expected parameters of the sources: 19 2 a)speotral brightness more then 10 Jphoton/om .s.eter.,keV. ?8 b) duration of an X-ray pulse less than 10 s. To evaluate the feasibility of making an X-ray souroe with the laser-plasma cathode of large scale the electromag?netic model of suoh a oathode was developed and tested. The possibility of the use of the ferroeleotrio emitter of electrons was disoussed. The research desoribed in this report was made possible in part by Grant Jlffl 1000 from the International Soience Foundation and by Grant ЛВ239665 from the Lawrenoe Livermore National Laboratory.
---------------------------
M.V. Belov , E.G. Devitsin , V.A. Kozlov , V.A. Nefedov , L.S. Popov , S.Y. Potashov , B.I. Zadneprovsky
№ 29 CHARACTERISTICS OF SCINTILLATING PBW04 CRYSTALS PRODUCED AT DIFFERENT GROWING-CONDITIONS
Скачать препринт |Аннотация|
The characteristics of heavy scintillating PbWO4 crystals produced at different growing conditions have been studied. All crystals were grown in All-Russian Research Institute of Synthesis of Mineral Raw Materials. Crystal colours arc varied from bright yellow (orange) to slight yellow and almost colourless do-pending on oxidation potential of the growing atmosphere. It is shown that colour centers in crystals are created due to the transition of part of lead ions in the melt into three valent state and its further re-entry into a crystal which causes defects involving Pb,i+. The measured light yield of the best samples was 6.4 % of that of BGO crystal. Decay times were established to be T\ = 1.95 ns, T2 = 6.9 ns, T3 = 28.5 ns. All samples were irradiated by 7-quanta from a powerfull 60Co source up to doses of 460 krad and 7 Mrad. For colourless samples the significant improve?ment in transmission spectra are observed for high dose of irradiation compared with low one as well as almost self annealing after 2 weeks of the exposure for one sample is seen.
---------------------------
V.M. Kolybasov
№ 31 PION-EXCHANGE TRIANGLE MECHANISM OF 11-PRODUCTION IN pd INTERACTIONS
Скачать препринт |Аннотация|
One of the simplest mechanisms is considered for the 77-production in re?actions pd ?? pdrj and pd ?? ppnrj which corresponds to the triangle graph with intermediate pion (or heavier meson). It is believed that the mech?anism is dominant or at least gives significant contribution in the energy region below and near r\ -meson production threshold in micleon nucleon collisions. It is shown that such mechanism can be reliably identified by observing the picture corresponding to so called moving complex triangle singularities: position and width of the peak in the (-qp) invariant mass distribution must distinctly vary with three?momentum transfer from ini?tial proton to final deuteron. Furthermore, that procedure gives a simple method to determine the mass of the meson whose exchange gives main contribution to the cross section of the process. The required experimental facilities are described. The topic is interesting from the point of view of 77 production inves?tigation as well as from the point of view of the possibility to isolate the contributions of the mechanisms different from quasi-free one (in our case it is triangle mechanism).
---------------------------
A.I. Lebedev , G.A. Sokol
№ 34 SEARCH FOR n-NUCLEI
Скачать препринт |Аннотация|
The results and proposals iu 7/-nuclei search in photon, hadron and ion induced reactions are briefly reviewed.
---------------------------
V.Ya. Nikulin , S.P. Tsybenko
№ 36 DISCONTINUITIES IN Z-PINCH PLASMAS
Скачать препринт |Аннотация|
Perpendicular shocks and tangential discontinuities under generalized con?ditions are obtained in a simple Davydov-Zakharov model [1]. We have es?tablished that the tangential discontinuity is unstable, and it can be used for an explanation of strong Z-pinch plasma inhomogeiieity along the Z axis while fast magnetic field penetration occurs. It is possible to reach the stable near anode penetration by two means: to employ a long duration current pulse which an amplitude is much less than the critical value or to prepare an appropriate profile of current pulse.
---------------------------
