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Methods of controlled formation of instabilities during the electrical explosion of thin foils
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作者 T.A.Shelkovenko I.N.Tilikin +3 位作者 A.V.Oginov A.R.Mingaleev V.M.Romanova S.A.Pikuz 《Matter and Radiation at Extremes》 SCIE EI CSCD 2023年第5期35-41,共7页
The results of a study of the electrical explosion of aluminum foils with an artificial periodic surface structure created by laser engraving are presented.Experiments were carried out on pulsed high-current generator... The results of a study of the electrical explosion of aluminum foils with an artificial periodic surface structure created by laser engraving are presented.Experiments were carried out on pulsed high-current generators BIN(270 kA,300 kV,100 ns)and KING(200 kA,40 kV,200 ns)with Al foil of thicknesses 16 and 4μm,respectively.Images of the exploded foils were recorded by point projection radiography in the radiation from hybrid X-pinches.It is found that the application of an artificial periodic structure to the foil leads to a much more uniform and well-defined periodic structure of the exploded foil.Images recorded in the UV range using a microchannel-plate-intensified detector show that the radiation from a surface-modified foil is more uniform along the entire length and width of the foil than that from a foil without modification. 展开更多
关键词 PERIODIC ELECTRICAL FOILS
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A Model of Accelerated Expansion of the Universe Based on the Idea about a Hypothetical 4-Dimensial Substance with an Inverse Population of Energy Levels
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作者 Evgeniy P. Orlov 《Journal of Modern Physics》 CAS 2023年第1期1-17,共17页
Based on the idea of hypothetical 4-dimensial substance with an inverse population of energy levels, a model of accelerated expansion of the Universe has been developed, which describes Hubble diagrams with great accu... Based on the idea of hypothetical 4-dimensial substance with an inverse population of energy levels, a model of accelerated expansion of the Universe has been developed, which describes Hubble diagrams with great accuracy for type Ia supernovae, quasars and gamma-ray burst sources at the Hubble parameter value of 67.7 km/s/Mpc, coinciding with the value obtained from analysis of inhomogeneities of relic radiation. Calculations at the Hubble parameter value of 73.5 km/s/Mpc, obtained using the ΛCDM model based on the analysis of data on type Ia supernovae and cepheids, differ markedly from the observed data. An explanation of the two values of the Hubble constant is proposed. It is shown that in this model, the magnitude of 13.8 billion years characterizes not the age of the Universe, but the time of propagation of light from those galaxes whose acceleration of removal has a minimal value. Based on the recently discovered curvature of the Universe, estimates are given of the lower limits of its size and lifetime, which turned out to be at least 270 billon years. The probability of transition from the excited state to the underlying energy levels of a hypothetical 4-dimensial substance, as well as the low of increasing energy density as a result of transitions to the underlying levels of this substance, is determined. 展开更多
关键词 4-Dimentional Space Hypothetical 4-Dimensional Substance 4-Dimensional Spherical Layer REDSHIFT Type Ia Supernovae QUASARS Gamma-Ray Bursts
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New Features of the Pulsar B0950+08 Radiation at the Frequency of 111 MHz
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作者 V.M.Malofeev I.F.Malov +1 位作者 O.I.Malov D.A.Teplykh 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2022年第3期88-99,共12页
Results of long time observations of the pulsar B0950+08 are given.These observations were carried out at the LPA radio telescope at the frequency of 111 MHz from January of 2016 to May of 2019(450 days).A strong vari... Results of long time observations of the pulsar B0950+08 are given.These observations were carried out at the LPA radio telescope at the frequency of 111 MHz from January of 2016 to May of 2019(450 days).A strong variability in emission of this pulsar has been detected with changes in signal to noise ratios hundreds of times.Part of the long-time flux density variability can be explained by refractive scintillations in the interstellar medium.The existence of radiation between the interpulse(IP)and main pulse(MP)was confirmed.It was more powerful than at high frequencies.We detected the unusual IP and precursor(Pr)radiation on 2017 August 1.On the basis of 65 strong IPs we found the correlations between energies of IP and Pr and between the phase of IP and the distance Pr–IP.It is shown that the observed peculiarities of this pulsar can be explained in the frame of the aligned rotator model.We estimated distances of radiation levels from the center of the neutron star.The calculated value of the initial period of 0.2 s means that not all pulsars are born with millisecond periods.The large age of the pulsar(6.8 million years)and the small angle between its magnetic moment and the rotation axis(less than 20°)confirm the suggestion related to pulsar evolution with respect to alignment. 展开更多
关键词 (stars:)pulsars:individual(PST B0950+08) radiation mechanisms:general (stars:)pulsars:general
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Core structure and secondary breakdown of an exploding wire in the current-pause regime
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作者 V.M.Romanova A.R.Mingaleev +3 位作者 A.E.Ter-Oganesyan T.A.Shelkovenko G.V.Ivanenkov S.A.Pikuz 《Matter and Radiation at Extremes》 SCIE CAS 2019年第2期43-51,共9页
The results of experiments with rapidly exploding thin conductors inthe current-pause regime are presented.Copper wires 25mmin diameter and 12 mm in length serve as loads for a GVP pulsed generator based on a low-indu... The results of experiments with rapidly exploding thin conductors inthe current-pause regime are presented.Copper wires 25mmin diameter and 12 mm in length serve as loads for a GVP pulsed generator based on a low-inductance capacitor.The generator produces current pulses of up to 10 kA with dI/dt up to 50 A/ns.A 100–800-ns current-pause regime is obtained for charging voltages of 10–15 kV.The discharge channel structure is studied by shadow photography using 0.53-mm,10-ns second-harmonic pulses from aNd31:YAG laser.In the experiments,three types of secondary breakdown are observed,with different symmetry types,different current-pause durations,and different dependences on the energy deposited into the wire during its resistive heating.All of these breakdown types develop inside a tubular core that is produced in the current-pause stage and that remains almost undamaged by the breakdown. 展开更多
关键词 BREAKDOWN REGIME structure
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Investigation of Al plasmas from thin foils irradiated by high-intensity extreme ultraviolet 被引量:1
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作者 E.V.Grabovski P.V.Sasorov +14 位作者 A.P.Shevelko V.V.Aleksandrov S.N.Andreev M.M.Basko A.V.Branitski A.N.Gritsuk G.S.Volkov Ya.N.Laukhin K.N.Mitrofanov G.M.Oleinik A.A.Samokhin V.P.Smirnov I.Yu.Tolstikhina I.N.Frolov O.F.Yakushev 《Matter and Radiation at Extremes》 SCIE EI CAS 2017年第3期129-138,共10页
Dynamics and spectral transmission of Al plasma produced by extreme ultraviolet(EUV)irradiation of 0.75-mm thick Al foil is investigated.The EUV radiation with the peak power density in the range of 0.19-0.54 TW/cm 2 ... Dynamics and spectral transmission of Al plasma produced by extreme ultraviolet(EUV)irradiation of 0.75-mm thick Al foil is investigated.The EUV radiation with the peak power density in the range of 0.19-0.54 TW/cm 2 is provided by Z-pinch formed by W multiwire array implosion in the Angara-5-1 facility.Geometry of the experiment ensures that there are no plasma fluxes from the pinch toward the Al foil and plasma.The same EUV source is used as a back illuminator for obtaining the absorption spectrum of Al plasma in the wavelength range of 5e24 nm.It comprises absorption lines of ions Al^(4+),Al^(5+),Al^(6+),Al^(7+).Analysis of relative intensities of the lines shows that those ions are formed in dense Al plasma with a temperature of~20 eV.Dynamics of Al plasma has been investigated with transverse laser probing.We have also performed radiation-gas-dynamics simulations of plasma dynamics affected by external radiation,which includes self-consistent radiation transport in a plasma shell.The simulations show good agreement with an experimental absorption spectrum and with experimental data concerning plasma dynamics,as well as with the analysis of line absorption spectrum.This confirms the correctness of the physical model underlying these simulations. 展开更多
关键词 Z-PINCH Dense plasma transparency
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Quantitative evaluation of LAL productivity of colloidal nanomaterials:Which laser pulse width is more productive,ergonomic,and economic?
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作者 Alena Nastulyavichus Nikita Smirnov Sergey Kudryashov 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第7期23-33,共11页
Near-IR(wavelength≈1μm)laser ablation of bulk,chemically-inert gold in water was compared for different laser pulse width in broad the range of 300 fs–100 ns,comparing a number of key ablation characteristics:mass ... Near-IR(wavelength≈1μm)laser ablation of bulk,chemically-inert gold in water was compared for different laser pulse width in broad the range of 300 fs–100 ns,comparing a number of key ablation characteristics:mass loss,singleshot crater volume and extinction coefficient of the generated colloidal solutions taken in the spectral ranges of interband transitions and localized plasmon resonance.Comparing to related air-based ablation results,at the given fluences laser ablation in the liquid resulted in the maximum ablation yield per unit energy and maximum NP yield per pulse and per unit energy for the picosecond lasers,occurring at subcritical peak pulse powers for laser self-focusing.The self-focusing effect was demonstrated to yield in incomplete,effectively weaker focusing in the water filaments of ultrashort laser pulses with supercritical peak powers,comparing to linear(geometrical)focusing at sub-critical peak powers.At the other,nanosecondpulse extreme the high ablation yield per pulse,but low ablation yield per unit energy and low NP yield per pulse and per unit energy were related to strong ablation plasma screening,providing mass removal according to the well-established scaling relationships for plasma.Illustrative comparison of the ablation and nanoparticle generation efficiency versus the broad fs–ns laser pulse width range was enabled in terms of productivity,economicity,and ergonomicity,using the proposed universal quantitative criteria. 展开更多
关键词 laser ablation of gold in liquid ablated mass critical power for self-focusing FILAMENTATION
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Optical spectra of plasmon-exciton core-shell nanoparticles:an anisotropic classical model eliminates discrepancies in experiments
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作者 Alexey D.Kondorskiy 《Chinese Optics Letters》 SCIE EI CAS CSCD 2024年第9期142-147,共6页
The optical properties of hybrid core-shell nanostructures composed of a metallic core and an organic shell of molecular J-aggregates are determined by the electromagnetic coupling between plasmons localized at the su... The optical properties of hybrid core-shell nanostructures composed of a metallic core and an organic shell of molecular J-aggregates are determined by the electromagnetic coupling between plasmons localized at the surface of the metallic core and Frenkel excitons in the shell.In cases of strong and ultra-strong plasmon-exciton coupling,the use of the traditional isotropic classical oscillator model to describe the J-aggregate permittivity may lead to drastic discrepancies between theoretical predictions and the available experimental spectra of hybrid nanoparticles.We show that these discrepancies are not caused by limitations of the classical oscillator model itself,but by considering the organic shell as an optically isotropic material.By assuming a tangential orientation of the classical oscillators of the molecular J-aggregates in a shell,we obtain excellent agreement with the experimental extinction spectra of TDBC-coated gold nanorods,which cannot be treated with the conventional isotropic shell model.Our results extend the understanding of the physical effects in the optics of metal-organic nanoparticles and suggest an approach for the theoretical description of such hybrid systems. 展开更多
关键词 nanomaterials PLASMONICS POLARITONS organic materials optical properties anisotropic optical materials scattering particles
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Highly efficient transient stimulated Raman scattering on secondary vibrational mode of BaWO_(4) crystal due to its constructive interference with self-phase modulation
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作者 Igor Kinyaevskiy Valeri Kovalev +4 位作者 Pavel Danilov Nikita Smirnov Sergey Kudryashov Andrey Koribut Andrey Ionin 《Chinese Optics Letters》 SCIE EI CAS CSCD 2023年第3期113-117,共5页
An exceptionally high stimulated Raman scattering[SRS]conversion efficiency to the first Stokes component associated with the secondary[low-frequency and low intensity]vibrational mode v2[~330 cm^[-1]]was observed in ... An exceptionally high stimulated Raman scattering[SRS]conversion efficiency to the first Stokes component associated with the secondary[low-frequency and low intensity]vibrational mode v2[~330 cm^[-1]]was observed in a BaWO4 crystal in a highly transient regime of interaction.The effect takes place in the range of pump pulse energy from~0.1 to~0.5μJ with maximum energy conversion efficiency up to 35%at 0.2μJ.The nature of the observed effects is explained by interference of SRS and self-phase modulation,where the latter is related to a noninstantaneous orientational Kerr nonlinearity in the BaWO4 crystal. 展开更多
关键词 stimulated Raman scattering secondary vibrational mode self-phase modulation ultrashort laser pulses transient phenomena
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Cross section of the Coulomb excitation of ^(229m)Th by low energy muons
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作者 E.V.Tkalya 《Chinese Physics C》 SCIE CAS CSCD 2021年第9期143-147,共5页
The inelastic scattering cross section for muons,μ^(-),with energies E=9-100 eV from the ^(229)Th nuclei is calculated in the framework of the second order of the perturbation theory for quantum electrodynamics.The d... The inelastic scattering cross section for muons,μ^(-),with energies E=9-100 eV from the ^(229)Th nuclei is calculated in the framework of the second order of the perturbation theory for quantum electrodynamics.The dominant contribution to the excitation of the low energy isomer ^(229m)Th(3/2^(+),8.19±0.12 eV)originates from the E2 multipole.The excitation cross section reaches the value of 10^(-21) cm^(2) in the range E≈10 eV.This value is four to five orders of magnitude larger than the electron excitation cross section and is sufficient for the efficient excitation of ^(229m)Th on the muon beam at the next generation of muon colliders. 展开更多
关键词 cross section MUON Coulomb excitation Th-229
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Is the existence of a J/ψJ/ψbound state plausible?
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作者 Xiang-Kun Dong Vadim Baru +3 位作者 Feng-Kun Guo Christoph Hanhart Alexey Nefediev Bing-Song Zou 《Science Bulletin》 SCIE EI CSCD 2021年第24期2462-2470,M0003,共10页
In a recent measurement LHCb reported pronounced structures in the J/ψJ/ψspectrum.One of the various possible explanations of those is that they emerge from non-perturbative interactions of vector charmonia.It is th... In a recent measurement LHCb reported pronounced structures in the J/ψJ/ψspectrum.One of the various possible explanations of those is that they emerge from non-perturbative interactions of vector charmonia.It is thus important to understand whether it is possible to form a bound state of two charmonia interacting through the exchange of gluons,which hadronise into two pions at the longest distance.In this paper,we demonstrate that,given our current understanding of hadron-hadron interactions,the exchange of correlated light mesons(pions and kaons)is able to provide sizeable attraction to the di-J/ψsystem,and it is possible for two J/ψmesons to form a bound state.As a side result we find from an analysis of the data for theψ/(2 S)J/ψππtransition including bothππand KK final state interactions an improved value for theψ(2 S)→J/ψtransition chromo-electric polarisability:|αψ(2 S)J/ψ|=(1.8±0.1)GeV-3,where the uncertainty also includes the one induced by the final state interactions. 展开更多
关键词 Fully-charm tetraquark Hadronic molecule Exotic hadron Dispersion relation
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Dielectronic recombination in non-LTE plasmas 被引量:1
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作者 F.B.Rosmej V.A.Astapenko +1 位作者 V.S.Lisitsa L.A.Vainshtein 《Matter and Radiation at Extremes》 SCIE CAS 2020年第6期1-20,共20页
Novel phenomena andmethods related to dielectronic capture and dielectronic recombination are studied for non-local thermodynamic equilibrium(LTE)plasmas and for applications to non-LTE ionization balance.It is demons... Novel phenomena andmethods related to dielectronic capture and dielectronic recombination are studied for non-local thermodynamic equilibrium(LTE)plasmas and for applications to non-LTE ionization balance.It is demonstrated thatmultichannel autoionization and radiative decay strongly suppress higher-order contributions to the total dielectronic recombination rates,which are overestimated by standard approaches by orders of magnitude.Excited-state coupling of dielectronic capture is shown to be much more important than ground-state contributions,and electron collisional excitation is also identified as a mechanism driving effective dielectronic recombination.A theoretical description of the effect of angularmomentum-changing collisions on dielectronic recombination is developed from an atomic kinetic point of view and is visualized with a simple analytical model.The perturbation of the autoionizing states due to electric fields is discussed with respect to ionization potential depression and perturbation of symmetry properties of autoionizationmatrix elements.The first steps in the development of statistical methods are presented and are realized in the framework of a local plasma frequency approach.Finally,the impact of collisional–radiative processes and atomic population kinetics on dielectronic recombination is critically discussed,and simple analytical formulas are presented. 展开更多
关键词 RADIATIVE PERTURBATION KINETICS
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Extreme matter compression caused by radiation cooling effect in gigabar shock wave driven by laser-accelerated fast electrons
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作者 S.Yu.Gus’kov P.A.Kuchugov G.A.Vergunova 《Matter and Radiation at Extremes》 SCIE CAS CSCD 2021年第2期1-7,共7页
Heating a solid material with laser-accelerated fast electrons is a particularly useful method for generating a plane powerful shock wave with a pressure of several hundred or even thousands of Mbar in the laboratory.... Heating a solid material with laser-accelerated fast electrons is a particularly useful method for generating a plane powerful shock wave with a pressure of several hundred or even thousands of Mbar in the laboratory.Behind the front of such a powerful shock wave,dense plasma is heated to a temperature of several keV.Then,a high rate of radiation energy loss occurs even in low-Z plasmas.In this paper,the strong compression of matter due to radiation cooling in a Gbar shock wave driven by fast electrons is studied using both computational and theoretical approaches.It is shown that the effect of radiation cooling leads to compression of matter in the peripheral region of the shock wave to a density several times greater than the density at its front.Heating a solid material by a petawatt flux of laser-accelerated fast electrons offers the opportunity to surpass the gigabar pressure level of plane shock waves generated by the impact of laser-accelerated pellets.Higher pressures of about 100 Gbar can be achieved under laboratory conditions only when a spherical target is imploded under the action of a terawatt laser pulse. 展开更多
关键词 LASER shock wave
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Elastic Moduli in Cadmium Selenide Doped with Chromium
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作者 N. S. Averkiev I. B. Bersuker +5 位作者 V. V. Gudkov I. V. Zhevstovskikh M. N. Sarychev S. Zherlitsyn Sh. Yasin Yu. V. Korostelin 《Journal of Applied Mathematics and Physics》 2017年第1期26-30,共5页
Temperature dependence of elastic moduli , , and the latter for the piezo-active and non-piezo-active versions, have been measured in the interval of 4 - 180 K at 28 - 262 MHz in a CdSe: Cr2+ crystal. Anomalies below ... Temperature dependence of elastic moduli , , and the latter for the piezo-active and non-piezo-active versions, have been measured in the interval of 4 - 180 K at 28 - 262 MHz in a CdSe: Cr2+ crystal. Anomalies below 40 K have been found for all the moduli, except . The interpretation of the results has been carried out involving the Jahn-Teller effect and relaxation between the equivalent distortions of the tetrahedral CrSe4 centers. 展开更多
关键词 Piezo-Electric CRYSTAL Ultrasound ELASTIC MODULI JAHN-TELLER Effect RELAXATION
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NH_(3)laser THz emission under optical pumping by“long”(~100μs)CO_(2)laser pulses 被引量:2
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作者 Andrey Alekseevich Ionin Igor Olegovich Kinyaevskiy +8 位作者 Yuri Mikhailovich Klimachev Andrey Yurievich Kozlov Darya Ivanovna Kormashova Andrey Alexandrovich Kotkov Yury Alekseevich Mityagin Sergey Alexandrovich Savinov Adilya Maratovna Sagitova Dmitry Vasilievich Sinitsyn Maxim Vladimirovich Ionin 《Chinese Optics Letters》 SCIE EI CAS CSCD 2023年第2期133-137,共5页
Terahertz(THz)NH_(3) lasing with optical pumping by electron-beam-sustained discharge“long”(~100μs)CO_(2) laser pulses was obtained.The NH3laser emission pulses and the“long”pulses of the CO_(2) pump laser were s... Terahertz(THz)NH_(3) lasing with optical pumping by electron-beam-sustained discharge“long”(~100μs)CO_(2) laser pulses was obtained.The NH3laser emission pulses and the“long”pulses of the CO_(2) pump laser were simultaneously measured with nanosecond response time.The NH3 lasing duration and its delay with respect to the pump pulse were measured for various CO_(2) laser pulse energies.For the CO_(2) laser pump line 9R(30),three wavelengths of 67.2,83.8,and 88.9μm were recorded.For the CO_(2) laser pump line 9R(16),only a single NH3 laser line with a wavelength of 90.4μm was detected. 展开更多
关键词 NH3 laser CO_(2)laser terahertz emission nanosecond response time
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Proposal for a nuclear light source
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作者 E.V.Tkalya P.V.Borisyuk +1 位作者 M.S.Domashenko Yu.Yu.Lebedinskii 《Chinese Physics C》 SCIE CAS CSCD 2023年第2期116-122,共7页
This study considers a principal possibility of creating a nuclear light source of the vacuum ultra violet(VUV) range based on the ^(229)Th nucleus.This nuclear light source can help solve two main problems—excitatio... This study considers a principal possibility of creating a nuclear light source of the vacuum ultra violet(VUV) range based on the ^(229)Th nucleus.This nuclear light source can help solve two main problems—excitation of the low-lying^(229m)Th isomer and precision measurement of the nuclear isomeric transition energy.The thorium nuclear light source is based on the nuclei implanted in a thin dielectric film with a large bandgap.While passing an electric current through the sample,the^(229)Th nuclei are excited to the low energy isomeric state 3/2^(+)(8.19±0.12eV) through the process of inelastic scattering of conduction electrons.The subsequent spontaneous decay of^(229m)Th is followed by the emission of γ quanta in the VUV range.The luminosity of the thorium nuclear light source is approximately 10^(5)photons/s per 1 A of current,per 1 ng of^(229)Th.The suggested scheme to obtain γ radiation from the^(229m)Th isomer can be considered as a type of nuclear analogue of the optical radiation from the usual metal-insulator-semiconductor(MIS) junction. 展开更多
关键词 Th-229m excitation by electrons optical range gamma emission
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Powerful terahertz waves from long-wavelength infrared laser filaments 被引量:8
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作者 Vladimir Yu.Fedorov Stelios Tzortzakis 《Light(Science & Applications)》 SCIE EI CAS CSCD 2020年第1期204-219,共16页
Strong terahertz(THz)electric and magnetic transients open up new horizons in science and applications.We review the most promising way of achieving sub-cycle THz pulses with extreme field strengths.During the nonline... Strong terahertz(THz)electric and magnetic transients open up new horizons in science and applications.We review the most promising way of achieving sub-cycle THz pulses with extreme field strengths.During the nonlinear propagation of two-color mid-infrared and far-infrared ultrashort laser pulses,long,and thick plasma strings are produced,where strong photocurrents result in intense THz transients.The corresponding THz electric and magnetic field strengths can potentially reach the gigavolt per centimeter and kilotesla levels,respectively.The intensities of these THz fields enable extreme nonlinear optics and relativistic physics.We offer a comprehensive review,starting from the microscopic physical processes of light-matter interactions with mid-infrared and far-infrared ultrashort laser pulses,the theoretical and numerical advances in the nonlinear propagation of these laser fields,and the most important experimental demonstrations to date. 展开更多
关键词 LASER EXTREME OPTICS
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