[Text] : статья / V.V. Derevyanko // Thermophysics and Aeromechanics. - 2001. - Vol. 8, № 3
Аннотация: The numerical modeling of the operation of a detonation MHD generator with T-layer has been performed at large pressures in the duct. It is shown that the radiation absorption inside the T-layer leads to a considerable variation of the layer characteristics, increase in the specific power and generator efficiency.
Полный текст в авторской редакции
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Деревянко, Виктор Валерьевич
Труды сотрудников ИВМ СО РАН
w10=
Найдено документов в текущей БД: 51
Scattering and absorption of resonant radiation in an expanding sphere
/ N.I. Kosarev, N.Y. Shaparev // J. Phys. B-At. Mol. Opt. Phys. - 2012. - Vol. 45, Is. 16. - Ст. 165003, DOI 10.1088/0953-4075/45/16/165003. - Cited References: 12
. - ISSN 0953-4075
РУБ Optics + Physics, Atomic, Molecular & Chemical
Аннотация: The radiative transfer in a freely expanding gaseous sphere, illuminated by external radiation, has been numerically studied. The absorption coefficient, spectral and spatial characteristics of the absorbed and scattered radiations, and the radial dependences of excited atomic concentration have been determined, and the influence of the optical thickness and the atomic radial expansion velocity on them has been investigated.
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович; Косарев Н.И.
Аннотация: The radiative transfer in a freely expanding gaseous sphere, illuminated by external radiation, has been numerically studied. The absorption coefficient, spectral and spatial characteristics of the absorbed and scattered radiations, and the radial dependences of excited atomic concentration have been determined, and the influence of the optical thickness and the atomic radial expansion velocity on them has been investigated.
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович; Косарев Н.И.
Scattering of resonant radiation in an expanding sphere
/ N. Y. Shaparev // 2012 INTERNATIONAL CONFERENCE ON OPTOELECTRONICS AND MICROELECTRONICS (ICOM) : IEEE COMPUTER SOC, 2012. - International Conference on Optoelectronics and Microelectronics (ICOM) (AUG 23-25, 2012, Changchun, PEOPLES R CHINA). - pp. 337-341. - Cited References: 12
. - ISBN 978-1-4673-2639-1
РУБ Engineering, Electrical & Electronic + Nanoscience & Nanotechnology + Optics
Аннотация: The radiative transfer in a freely expanding gaseous sphere, illuminated by external radiation, has been studied numerically. The absorption coefficient, spectral and spatial characteristics of the absorbed and scattered radiation, the radial dependences of excited atomic concentration have been determined, the influence of the optical thickness and the atomic radial expansion velocity on them have been investigated.
РИНЦ
Доп.точки доступа:
Шапарев, Николай Якимович
Аннотация: The radiative transfer in a freely expanding gaseous sphere, illuminated by external radiation, has been studied numerically. The absorption coefficient, spectral and spatial characteristics of the absorbed and scattered radiation, the radial dependences of excited atomic concentration have been determined, the influence of the optical thickness and the atomic radial expansion velocity on them have been investigated.
РИНЦ
Доп.точки доступа:
Шапарев, Николай Якимович
Engineering, Electrical & Electronic
S53
S53
Reduced Absorption of Resonance Radiation in Expanding Gas
/ N.Y. Shaparev // 2012 INTERNATIONAL CONFERENCE ON OPTOELECTRONICS AND MICROELECTRONICS (ICOM) : IEEE COMPUTER SOC, 2012. - International Conference on Optoelectronics and Microelectronics (ICOM) (AUG 23-25, 2012, Changchun, PEOPLES R CHINA). - pp. 342-345. - Cited References: 14
. - ISBN 978-1-4673-2639-1
РУБ Engineering, Electrical & Electronic + Nanoscience & Nanotechnology + Optics
Аннотация: The paper deals with absorption of resonance and continuum radiation in an expanding gaseous sphere. For self-similar expansion, a probability of radiation to be transmitted is studied depending on the velocity gradient and optical thickness. It is shown that an optically thick medium grows thinner with the velocity gradient.
РИНЦ
Доп.точки доступа:
Шапарев, Николай Якимович
Рубрики:
SCORPII
Кл.слова (ненормированные):
line shapes -- widths -- emission -- absorption -- scattering of electromagnetic radiationr -- radiative processes -- solar radiation
SCORPII
Кл.слова (ненормированные):
line shapes -- widths -- emission -- absorption -- scattering of electromagnetic radiationr -- radiative processes -- solar radiation
Аннотация: The paper deals with absorption of resonance and continuum radiation in an expanding gaseous sphere. For self-similar expansion, a probability of radiation to be transmitted is studied depending on the velocity gradient and optical thickness. It is shown that an optically thick medium grows thinner with the velocity gradient.
РИНЦ
Доп.точки доступа:
Шапарев, Николай Якимович
The spectrum of resonant laser radiation to decelerate ions in an expanding ultracold plasma
/ N.Y. Shaparev // Laser Physics Letters. - 2013. - Vol. 10, Is. 8. - Ст. 085501, DOI 10.1088/1612-2011/10/8/085501
. - ISSN 1612-2011
Аннотация: We analyze the resonance absorption spectrum of ions in an expanding ultracold spherical plasma. It is shown that the spectrum width is controlled by the highest expansion velocity at the sphere boundary. As the expansion velocity grows, the initial optical thickness of the medium decreases and the medium becomes transparent. We suggest broadband laser radiation in the red absorption spectrum of ions be used to decelerate ions in an expanding plasma in order to achieve crystallization. В© 2013 Astro Ltd.
Scopus
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович
Аннотация: We analyze the resonance absorption spectrum of ions in an expanding ultracold spherical plasma. It is shown that the spectrum width is controlled by the highest expansion velocity at the sphere boundary. As the expansion velocity grows, the initial optical thickness of the medium decreases and the medium becomes transparent. We suggest broadband laser radiation in the red absorption spectrum of ions be used to decelerate ions in an expanding plasma in order to achieve crystallization. В© 2013 Astro Ltd.
Scopus
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович
Transfer of resonance radiation in an expanding sphere
[Text] / N.I. Kosarev, N.Y. Shaparev // J. Phys. B-At. Mol. Opt. Phys. - 2011. - Vol. 44, Is. 19. - Ст. 195402, DOI 10.1088/0953-4075/44/19/195402. - Cited References: 17
. - ISSN 0953-4075
РУБ Optics + Physics, Atomic, Molecular & Chemical
Аннотация: Imprisonment of resonant radiation in an expanding sphere on the basis of the numerical solution of the rate balance equation for excited atoms and the transfer resonance radiation equation is investigated. Calculations of the escape factor for sphere at Doppler form of absorption and scattering profiles are executed. The effect of spectral shift of the absorption (emission) profile relative to the stationary one due to expansion of the medium is taken into account for the case when differential motion is described by velocity that varies linearly with the radius. The behaviour of the escape factor for the sphere is compared with the Sobolev theory. The numerical date for time dependence of intensity of afterglow and contour of the spectral line of leaving outside resonance radiation and spatial distribution of the excited atomic concentration are submitted as well.
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович; Косарев Н.И.
Рубрики:
PLASMAS
PLASMAS
Аннотация: Imprisonment of resonant radiation in an expanding sphere on the basis of the numerical solution of the rate balance equation for excited atoms and the transfer resonance radiation equation is investigated. Calculations of the escape factor for sphere at Doppler form of absorption and scattering profiles are executed. The effect of spectral shift of the absorption (emission) profile relative to the stationary one due to expansion of the medium is taken into account for the case when differential motion is described by velocity that varies linearly with the radius. The behaviour of the escape factor for the sphere is compared with the Sobolev theory. The numerical date for time dependence of intensity of afterglow and contour of the spectral line of leaving outside resonance radiation and spatial distribution of the excited atomic concentration are submitted as well.
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович; Косарев Н.И.
Imprisonment dynamics of resonance radiation in gases
[Text] / N.I. Kosarev, N.Y. Shaparev // J. Phys. B-At. Mol. Opt. Phys. - 2011. - Vol. 44, Is. 10. - Ст. 105402, DOI 10.1088/0953-4075/44/10/105402. - Cited References: 9
. - ISSN 0953-4075
РУБ Optics + Physics, Atomic, Molecular & Chemical
Аннотация: Imprisonment of resonant radiation in gases on the basis of the numerical solution of the rate balance equation for the excited atoms and the transfer resonant radiation equation is investigated. Calculations of the escape factor for the slab, cylinder and sphere at Doppler and Lorentz forms of absorption and scattering profiles are executed. Calculation results of the escape factor for the cylinder and slab are compared with Holsten's asymptotical solutions. The numerical data for time dependence of a spectrum, the intensity of resonant radiation and the spatial distribution of the excited atomic concentration in a regime of afterglow are also considered.
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович; Косарев Н.И.
Рубрики:
ULTRACOLD LASER-PLASMA
ULTRACOLD LASER-PLASMA
Аннотация: Imprisonment of resonant radiation in gases on the basis of the numerical solution of the rate balance equation for the excited atoms and the transfer resonant radiation equation is investigated. Calculations of the escape factor for the slab, cylinder and sphere at Doppler and Lorentz forms of absorption and scattering profiles are executed. Calculation results of the escape factor for the cylinder and slab are compared with Holsten's asymptotical solutions. The numerical data for time dependence of a spectrum, the intensity of resonant radiation and the spatial distribution of the excited atomic concentration in a regime of afterglow are also considered.
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович; Косарев Н.И.
Absorption of resonance radiation in ultracold laser plasma
[Text] / N.I. Kosarev, N.Y. Shaparev // Dokl. Phys. - 2008. - Vol. 53, Is. 8. - pp. 428-430, DOI 10.1134/S1028335808080053. - Cited References: 10
. - ISSN 1028-3358
РУБ Mechanics + Physics, Multidisciplinary
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович; Косарев Н.И.
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович; Косарев Н.И.
Resonance laser-induced ionisation of sodium vapour taking radiative transfer into account
[Text] / N.I. Kosarev, N.Y. Shaparev // Quantum Electron. - 2006. - Vol. 36, Is. 4. - pp. 369-375, DOI 10.1070/QE2006v036n04ABEH013153. - Cited References: 23
. - ISSN 1063-7818
РУБ Engineering, Electrical & Electronic + Physics, Applied
Аннотация: The problem of ionisation of atomic sodium in the field of resonance laser radiation is numerically solved taking radiative transfer into account. Seed electrons are produced due to the mechanism of associative ionisation, then they gain energy in superelastic processes (collisions of the second kind) and initiate the avalanche ionisation of the medium by electron impact. We studied the effect of secondary radiation on the laser pulse propagation upon competition between the ionising and quenching electron collisions with excited atoms, on the kinetics of ionisation-induced vapour bleaching, and the plasma channel expansion in the form of a halo.
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович; Косарев Н.И.
Рубрики:
CHANNEL FORMATION
SATURATION
FIELD
MODEL
GAS
Кл.слова (ненормированные):
spontaneous decay -- excitation -- de-excitation -- absorption coefficient -- source function -- transparency -- bleaching -- radiative transfer -- photoplasma
CHANNEL FORMATION
SATURATION
FIELD
MODEL
GAS
Кл.слова (ненормированные):
spontaneous decay -- excitation -- de-excitation -- absorption coefficient -- source function -- transparency -- bleaching -- radiative transfer -- photoplasma
Аннотация: The problem of ionisation of atomic sodium in the field of resonance laser radiation is numerically solved taking radiative transfer into account. Seed electrons are produced due to the mechanism of associative ionisation, then they gain energy in superelastic processes (collisions of the second kind) and initiate the avalanche ionisation of the medium by electron impact. We studied the effect of secondary radiation on the laser pulse propagation upon competition between the ionising and quenching electron collisions with excited atoms, on the kinetics of ionisation-induced vapour bleaching, and the plasma channel expansion in the form of a halo.
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович; Косарев Н.И.
Resonant optical characteristics of an ultracold laser plasma
[Text] / N.I. Kosarev, N.Y. Shaparev // Quantum Electron. - 2009. - Vol. 39, Is. 12. - pp. 1112-1116, DOI 10.1070/QE2009v039n12ABEH014094. - Cited References: 13
. - ISSN 1063-7818
РУБ Engineering, Electrical & Electronic + Physics, Applied
Аннотация: We report a computer simulation study of light absorption, scattering and emission at 397 nm in an ultracold calcium ion plasma under resonant excitation. The results point to spectral asymmetry of light scattering, nonlinear absorption, and emission in the plasma. An approach is proposed for ultracold plasma diagnostics using resonant optical characteristics.
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович; Косарев Н.И.
Рубрики:
NEUTRAL PLASMA
CRYSTALLIZATION
TRAP
Кл.слова (ненормированные):
ultracold laser plasma -- resonant excitation -- optical characteristics
NEUTRAL PLASMA
CRYSTALLIZATION
TRAP
Кл.слова (ненормированные):
ultracold laser plasma -- resonant excitation -- optical characteristics
Аннотация: We report a computer simulation study of light absorption, scattering and emission at 397 nm in an ultracold calcium ion plasma under resonant excitation. The results point to spectral asymmetry of light scattering, nonlinear absorption, and emission in the plasma. An approach is proposed for ultracold plasma diagnostics using resonant optical characteristics.
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович; Косарев Н.И.
Absorption and scattering of resonance laser radiation in ultracold optical dense plasma
[Text] / N. I. Kosarev, N. J. Shaparev // J. Phys. B-At. Mol. Opt. Phys. - 2008. - Vol. 41, Is. 23. - Ст. 235701, DOI 10.1088/0953-4075/41/23/235701. - Cited References: 12
. - ISSN 0953-4075
РУБ Optics + Physics, Atomic, Molecular & Chemical
Аннотация: The problem of absorption and scattering of resonance laser radiation in ultracold optical dense plasma has been studied numerically. The frequency asymmetry of scattering and nonlinear absorption of light is predicted.
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович
Аннотация: The problem of absorption and scattering of resonance laser radiation in ultracold optical dense plasma has been studied numerically. The frequency asymmetry of scattering and nonlinear absorption of light is predicted.
Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович
Analytical assessments of electron temperature and kinetics of gas ionization in the resonance field
/ A. P. Gavrilyuk // Teplofizika Vysokikh Temperatur. - 1995. - Vol. 33, Is. 1. - P144-146
. - ISSN 0040-3644
Кл.слова (ненормированные):
Electrons -- Equations of state of gases -- Laser beams -- Plasma heating -- Resonance -- Temperature measurement -- Electron temperature -- Resonance field -- Ionization of gases
Аннотация: The paper assesses coefficients and rates of ionization caused by an electron shock of atomic gas. It is meant that this gas is excited by resonance radiation and that ionization rate depends on the tune out of radiation frequency from the center of absorption line. It has been shown that in the central part of the line, where saturation is implemented, the coefficient depends only on characteristics of the resonance transition and ionization potential of the atom, and that the growth of electron concentration in time is exponential. When the far end of the line is tuned out, saturation disappears and dynamics of concentration growth becomes nonlinear.
Scopus
Держатели документа:
VTs SO RAN, Krasnoyarsk, Russian Federation
ИВМ СО РАН
Доп.точки доступа:
Gavrilyuk, A.P.; Гаврилюк, Анатолий Петрович
Кл.слова (ненормированные):
Electrons -- Equations of state of gases -- Laser beams -- Plasma heating -- Resonance -- Temperature measurement -- Electron temperature -- Resonance field -- Ionization of gases
Аннотация: The paper assesses coefficients and rates of ionization caused by an electron shock of atomic gas. It is meant that this gas is excited by resonance radiation and that ionization rate depends on the tune out of radiation frequency from the center of absorption line. It has been shown that in the central part of the line, where saturation is implemented, the coefficient depends only on characteristics of the resonance transition and ionization potential of the atom, and that the growth of electron concentration in time is exponential. When the far end of the line is tuned out, saturation disappears and dynamics of concentration growth becomes nonlinear.
Scopus
Держатели документа:
VTs SO RAN, Krasnoyarsk, Russian Federation
ИВМ СО РАН
Доп.точки доступа:
Gavrilyuk, A.P.; Гаврилюк, Анатолий Петрович
Spectroscopic manifestations of the catastrophe of the resonant optical bunching of ion velocities
/ I. V. Krasnov, N. Ya. Shaparev // Optics and Spectroscopy (English translation of Optika i Spektroskopiya). - 1996. - Vol. 80, Is. 4. - P577-580
. - ISSN 0030-400X
Аннотация: Collective ion interactions are shown to considerably change the usual physical picture of bunching of the resonant particle velocities by the force of spontaneous light pressure. This manifests itself in the direct destruction of the process of bunching the ion velocities and the appearance of an overthermal structure in the spectrum of plasma noises. In this case, the spectral density of noises as a function of the phase velocity of plasma waves proves to be a mapping of the optical absorption spectrum and resolves the sub-Doppler structure of the optical resonance.
Scopus
Держатели документа:
Computer Center, Siberian Division, Russian Academy of Sciences, Krasnoyarsk, 660036, Russian Federation
Krasnoyarsk State University, Krasnoyarsk, 660062, Russian Federation
ИВМ СО РАН
Доп.точки доступа:
Krasnov, I.V.; Краснов, Игорь Васильевич; Shaparev, N.Ya.; Шапарев, Николай Якимович
Аннотация: Collective ion interactions are shown to considerably change the usual physical picture of bunching of the resonant particle velocities by the force of spontaneous light pressure. This manifests itself in the direct destruction of the process of bunching the ion velocities and the appearance of an overthermal structure in the spectrum of plasma noises. In this case, the spectral density of noises as a function of the phase velocity of plasma waves proves to be a mapping of the optical absorption spectrum and resolves the sub-Doppler structure of the optical resonance.
Scopus
Держатели документа:
Computer Center, Siberian Division, Russian Academy of Sciences, Krasnoyarsk, 660036, Russian Federation
Krasnoyarsk State University, Krasnoyarsk, 660062, Russian Federation
ИВМ СО РАН
Доп.точки доступа:
Krasnov, I.V.; Краснов, Игорь Васильевич; Shaparev, N.Ya.; Шапарев, Николай Якимович
Reduction of the resonance radiation absorption in expanding gas
/ N. Y. Shaparev // Dokl. Phys. - 2013. - Vol. 58, Is. 2. - P. 45-47, DOI 10.1134/S1028335813020031. - Cited References: 6
. - ISSN 1028-3358
РУБ Mechanics + Physics, Multidisciplinary
Держатели документа:
Russian Acad Sci, Inst Computat Modeling, Siberian Branch, Krasnoyarsk 660036, Russia
ИВМ СО РАН
Доп.точки доступа:
Шапарев, Николай Якимович
Рубрики:
PLASMAS
PLASMAS
Держатели документа:
Russian Acad Sci, Inst Computat Modeling, Siberian Branch, Krasnoyarsk 660036, Russia
ИВМ СО РАН
Доп.точки доступа:
Шапарев, Николай Якимович
Absorption of continuum radiation in a resonant expanding gaseous sphere
[Text] / N. Y. Shaparev // J. Phys. B-At. Mol. Opt. Phys. - 2014. - Vol. 47, Is. 22. - Ст. 225401, DOI 10.1088/0953-4075/47/22/225401. - Cited References: 11
. - ISSN 0953-4075. - ISSN 1361-6455
РУБ Optics + Physics, Atomic, Molecular & Chemical
Аннотация: The paper deals with absorption of external continuum radiation in a self-similarly expanding gaseous sphere. Frequency probability and integral probability of radiation absorption in the resonance frequency range are determined depending on the expansion velocity gradient and thickness of the optical medium. It is shown that expansion results in a reduced optical thickness of the medium and enhanced integral absorption.
WOS
Держатели документа:
Russian Acad Sci, Inst Computat Modeling, Krasnoyarsk 660036, Russia
ИВМ СО РАН
Доп.точки доступа:
Шапарев, Николай Якимович
Аннотация: The paper deals with absorption of external continuum radiation in a self-similarly expanding gaseous sphere. Frequency probability and integral probability of radiation absorption in the resonance frequency range are determined depending on the expansion velocity gradient and thickness of the optical medium. It is shown that expansion results in a reduced optical thickness of the medium and enhanced integral absorption.
WOS
Держатели документа:
Russian Acad Sci, Inst Computat Modeling, Krasnoyarsk 660036, Russia
ИВМ СО РАН
Доп.точки доступа:
Шапарев, Николай Якимович
Impact induced surface heating by planetesimals on early Mars
/ T. I. Maindl [et al.] // Astron. Astrophys. - 2015. - Vol. 574, DOI 10.1051/0004-6361/201424256
. - ISSN 0004-6361
Кл.слова (ненормированные):
Celestial mechanics -- Planets and satellites: Atmospheres -- Planets and satellites: Formation -- Planets and satellites: Terrestrial planets -- Stars: Solar-type -- Sun: UV radiation -- Astrophysics -- Atmospheric temperature -- Carbon dioxide -- Energy transfer -- Fluid dynamics -- Hydrodynamics -- Planets -- Upper atmosphere -- Celestial mechanics -- Planets and satellites: atmospheres -- Planets and satellites: formation -- Stars: solar types -- Sun:UV radiation -- Terrestrial planets -- Satellites
Аннотация: Aims. We investigate the influence of impacts of large planetesimals and small planetary embryos on the early Martian surface on the hydrodynamic escape of an early steam atmosphere that is exposed to the high soft X-ray and extreme-ultraviolet (EUV) flux of the young Sun. Methods. Impact statistics in terms of number, masses, velocities, and angles of asteroid impacts onto early Mars are determined via n-body integrations. Based on these statistics, smoothed particle hydrodynamics (SPH) simulations result in estimates of energy transfer into the planetary surface material and the resulting surface heating. For the estimation of the atmospheric escape rates we applied a soft X-ray and EUV absorption model and a 1D upper atmosphere hydrodynamic model to a magma ocean-related catastrophically outgassed steam atmosphere with surface pressure values of 52 bar H2O and 11 bar CO2. Results. The estimated impact rates and energy deposition onto an early Martian surface can account for substantial heating. The energy influx and conversion rate into internal energy is probably sufficient to keep a shallow magma ocean liquid for an extended period of time. Higher surface temperatures keep the outgassed steam atmosphere longer in vapor form and therefore enhance its escape to space within ?0.6 Myr after its formation.
Scopus,
WOS
Держатели документа:
Institute for Computational Modelling, Russian Academy of SciencesKrasnoyarsk 36, Russian Federation
Доп.точки доступа:
Maindl, T.I.; Dvorak, R.; Lammer, H.; Gudel, M.; Schafer, C.; Speith, R.; Odert, P.; Erkaev, N.V.; Еркаев, Николай Васильевич; Kislyakova, K.G.; Pilat-Lohinger, E.
Кл.слова (ненормированные):
Celestial mechanics -- Planets and satellites: Atmospheres -- Planets and satellites: Formation -- Planets and satellites: Terrestrial planets -- Stars: Solar-type -- Sun: UV radiation -- Astrophysics -- Atmospheric temperature -- Carbon dioxide -- Energy transfer -- Fluid dynamics -- Hydrodynamics -- Planets -- Upper atmosphere -- Celestial mechanics -- Planets and satellites: atmospheres -- Planets and satellites: formation -- Stars: solar types -- Sun:UV radiation -- Terrestrial planets -- Satellites
Аннотация: Aims. We investigate the influence of impacts of large planetesimals and small planetary embryos on the early Martian surface on the hydrodynamic escape of an early steam atmosphere that is exposed to the high soft X-ray and extreme-ultraviolet (EUV) flux of the young Sun. Methods. Impact statistics in terms of number, masses, velocities, and angles of asteroid impacts onto early Mars are determined via n-body integrations. Based on these statistics, smoothed particle hydrodynamics (SPH) simulations result in estimates of energy transfer into the planetary surface material and the resulting surface heating. For the estimation of the atmospheric escape rates we applied a soft X-ray and EUV absorption model and a 1D upper atmosphere hydrodynamic model to a magma ocean-related catastrophically outgassed steam atmosphere with surface pressure values of 52 bar H2O and 11 bar CO2. Results. The estimated impact rates and energy deposition onto an early Martian surface can account for substantial heating. The energy influx and conversion rate into internal energy is probably sufficient to keep a shallow magma ocean liquid for an extended period of time. Higher surface temperatures keep the outgassed steam atmosphere longer in vapor form and therefore enhance its escape to space within ?0.6 Myr after its formation.
Scopus,
WOS
Держатели документа:
Institute for Computational Modelling, Russian Academy of SciencesKrasnoyarsk 36, Russian Federation
Доп.точки доступа:
Maindl, T.I.; Dvorak, R.; Lammer, H.; Gudel, M.; Schafer, C.; Speith, R.; Odert, P.; Erkaev, N.V.; Еркаев, Николай Васильевич; Kislyakova, K.G.; Pilat-Lohinger, E.
Origin and Stability of Exomoon Atmospheres: Implications for Habitability
/ H. Lammer [et al.] // Origins of Life and Evolution of Biospheres. - 2014. - Vol. 44, Iss. 3. - P239-260, DOI 10.1007/s11084-014-9377-2
. - ISSN 0169-6149
Кл.слова (ненормированные):
Atmospheric escape -- Exomoons -- Exoplanets -- Habitabilty -- Protoatmospheres -- Young stars
Аннотация: We study the origin and escape of catastrophically outgassed volatiles (H2O, CO2) from exomoons with Earth-like densities and masses of 0.1, 0.5 and 1 M? orbiting an extra-solar gas giant inside the habitable zone of a young active solar-like star. We apply a radiation absorption and hydrodynamic upper atmosphere model to the three studied exomoon cases. We model the escape of hydrogen and dragged dissociation products O and C during the activity saturation phase of the young host star. Because the soft X-ray and EUV radiation of the young host star may be up to ~100 times higher compared to today’s solar value during the first 100 Myr after the system’s origin, an exomoon with a mass < 0.25 M? located in the HZ may not be able to keep an atmosphere because of its low gravity. Depending on the spectral type and XUV activity evolution of the host star, exomoons with masses between ~0.25 and 0.5 M? may evolve to Mars-like habitats. More massive bodies with masses >0.5 M?, however, may evolve to habitats that are a mixture of Mars-like and Earth-analogue habitats, so that life may originate and evolve at the exomoon’s surface.
WOS,
Scopus
Доп.точки доступа:
Lammer, H.; Schiefer, S.-C.; Juvan, I.; Odert, P.; Erkaev, N.V.; Еркаев, Николай Васильевич; Weber, C.; Kislyakova, K.G.; Gudel, M.; Kirchengast, G.; Hanslmeier, A.
Кл.слова (ненормированные):
Atmospheric escape -- Exomoons -- Exoplanets -- Habitabilty -- Protoatmospheres -- Young stars
Аннотация: We study the origin and escape of catastrophically outgassed volatiles (H2O, CO2) from exomoons with Earth-like densities and masses of 0.1, 0.5 and 1 M? orbiting an extra-solar gas giant inside the habitable zone of a young active solar-like star. We apply a radiation absorption and hydrodynamic upper atmosphere model to the three studied exomoon cases. We model the escape of hydrogen and dragged dissociation products O and C during the activity saturation phase of the young host star. Because the soft X-ray and EUV radiation of the young host star may be up to ~100 times higher compared to today’s solar value during the first 100 Myr after the system’s origin, an exomoon with a mass < 0.25 M? located in the HZ may not be able to keep an atmosphere because of its low gravity. Depending on the spectral type and XUV activity evolution of the host star, exomoons with masses between ~0.25 and 0.5 M? may evolve to Mars-like habitats. More massive bodies with masses >0.5 M?, however, may evolve to habitats that are a mixture of Mars-like and Earth-analogue habitats, so that life may originate and evolve at the exomoon’s surface.
WOS,
Scopus
Доп.точки доступа:
Lammer, H.; Schiefer, S.-C.; Juvan, I.; Odert, P.; Erkaev, N.V.; Еркаев, Николай Васильевич; Weber, C.; Kislyakova, K.G.; Gudel, M.; Kirchengast, G.; Hanslmeier, A.
Extreme hydrodynamic atmospheric loss near the critical thermal escape regime
[Text] / N. V. Erkaev [et al.] // Mon. Not. Roy. Astron. Soc. - 2015. - Vol. 448, Is. 2. - P1916-1921, DOI 10.1093/mnras/stv130. - Cited References:28. - The authors acknowledge the support by the FWF NFN project S11601-N16 'Pathways to Habitability: From Disks to Active Stars, Planets and Life', and the related FWF NFN subproject, S11607-N16 'Particle/Radiative Interactions with Upper Atmospheres of Planetary Bodies Under Extreme Stellar Conditions'. PO acknowledges support from the FWF project P22950-N16. NVE acknowledges support by the RFBR grant no. 15-05-00879-a. Finally, the authors thank the International Space Science Institute (ISSI) in Bern, and the ISSI team 'Characterizing stellar-and exoplanetary environments'.
. - ISSN 0035-8711. - ISSN 1365-2966
РУБ Astronomy & Astrophysics
Аннотация: By considering martian-like planetary embryos inside the habitable zone of solar-like stars we study the behaviour of the hydrodynamic atmospheric escape of hydrogen for small values of the Jeans escape parameter beta < 3, near the base of the thermosphere, that is defined as a ratio of the gravitational and thermal energy. Our study is based on a 1D hydrodynamic upper atmosphere model that calculates the volume heating rate in a hydrogen-dominated thermosphere due to the absorption of the stellar soft X-ray and extreme ultraviolet (XUV) flux. In case of a monatomic gas, we find that when the beta value near the mesopause/homopause level exceeds a critical value of similar to 2.5, there exists a steady hydrodynamic solution with a smooth transition from subsonic to supersonic flow. For a fixed XUV flux, the escape rate of the upper atmosphere is an increasing function of the temperature at the lower boundary. Our model results indicate a crucial enhancement of the atmospheric escape rate, when the Jeans escape parameter beta decreases to this critical value. When beta becomes <= 2.5, there is no stationary hydrodynamic transition from subsonic to supersonic flow. This is the case of a fast non-stationary atmospheric expansion that results in extreme thermal atmospheric escape rates.
WOS,
Scopus,
Полный текст на сайте журнала
Держатели документа:
Inst Computat Modelling SB RAS, Krasnoyarsk 660036, Russia.
Siberian Fed Univ, Krasnoyarsk 660041, Russia.
Austrian Acad Sci, Space Res Inst, A-8042 Graz, Austria.
Graz Univ, Inst Phys, A-8010 Graz, Austria.
Russian Acad Sci, Polar Geophys Inst, Murmansk 183010, Russia.
ИВМ СО РАН
Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Lammer, H.; Odert, P.; Kulikov, Yu. N.; Kislyakova, K.G.; FWF NFN [S11601-N16, S11607-N16]; FWF [P22950-N16]; RFBR [15-05-00879-a]
Рубрики:
PRIMORDIAL TERRESTRIAL ATMOSPHERE
STELLAR WINDS
SUPER-EARTHS
Кл.слова (ненормированные):
hydrodynamics -- planets and satellites: atmospheres -- planets and -- satellites: physical evolution -- ultraviolet: planetary systems
PRIMORDIAL TERRESTRIAL ATMOSPHERE
STELLAR WINDS
SUPER-EARTHS
Кл.слова (ненормированные):
hydrodynamics -- planets and satellites: atmospheres -- planets and -- satellites: physical evolution -- ultraviolet: planetary systems
Аннотация: By considering martian-like planetary embryos inside the habitable zone of solar-like stars we study the behaviour of the hydrodynamic atmospheric escape of hydrogen for small values of the Jeans escape parameter beta < 3, near the base of the thermosphere, that is defined as a ratio of the gravitational and thermal energy. Our study is based on a 1D hydrodynamic upper atmosphere model that calculates the volume heating rate in a hydrogen-dominated thermosphere due to the absorption of the stellar soft X-ray and extreme ultraviolet (XUV) flux. In case of a monatomic gas, we find that when the beta value near the mesopause/homopause level exceeds a critical value of similar to 2.5, there exists a steady hydrodynamic solution with a smooth transition from subsonic to supersonic flow. For a fixed XUV flux, the escape rate of the upper atmosphere is an increasing function of the temperature at the lower boundary. Our model results indicate a crucial enhancement of the atmospheric escape rate, when the Jeans escape parameter beta decreases to this critical value. When beta becomes <= 2.5, there is no stationary hydrodynamic transition from subsonic to supersonic flow. This is the case of a fast non-stationary atmospheric expansion that results in extreme thermal atmospheric escape rates.
WOS,
Scopus,
Полный текст на сайте журнала
Держатели документа:
Inst Computat Modelling SB RAS, Krasnoyarsk 660036, Russia.
Siberian Fed Univ, Krasnoyarsk 660041, Russia.
Austrian Acad Sci, Space Res Inst, A-8042 Graz, Austria.
Graz Univ, Inst Phys, A-8010 Graz, Austria.
Russian Acad Sci, Polar Geophys Inst, Murmansk 183010, Russia.
ИВМ СО РАН
Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Lammer, H.; Odert, P.; Kulikov, Yu. N.; Kislyakova, K.G.; FWF NFN [S11601-N16, S11607-N16]; FWF [P22950-N16]; RFBR [15-05-00879-a]
Continuum Radiation Absorption in Resonant Expanding Gas Media
/ N. Y. Shaparev // Russ. Phys. J. - 2015. - Vol. 58, Is. 2. - P198-204, DOI 10.1007/s11182-015-0482-0
. - ISSN 1064-8887
Аннотация: The absorption of external radiation and continuum radiation originating from the center in a self-similar expanding gas sphere is considered. The frequency and integral probabilities of radiation absorption in a resonance frequency domain are analyzed depending on the expansion velocity gradient and the optical thickness of the medium. It is demonstrated that the optical density of the medium decreases and the integral absorption increases in the expanding medium. © 2015, Springer Science+Business Media New York.
Scopus,
WOS
Держатели документа:
Institute of Computational Modeling of the Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk, Russian Federation
National Research Tomsk State University, Tomsk, Russian Federation
Доп.точки доступа:
Шапарев, Николай Якимович
Аннотация: The absorption of external radiation and continuum radiation originating from the center in a self-similar expanding gas sphere is considered. The frequency and integral probabilities of radiation absorption in a resonance frequency domain are analyzed depending on the expansion velocity gradient and the optical thickness of the medium. It is demonstrated that the optical density of the medium decreases and the integral absorption increases in the expanding medium. © 2015, Springer Science+Business Media New York.
Scopus,
WOS
Держатели документа:
Institute of Computational Modeling of the Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk, Russian Federation
National Research Tomsk State University, Tomsk, Russian Federation
Доп.точки доступа:
Шапарев, Николай Якимович
Onset of convection in a two-phase binary mixture with the Soret effect in weightlessness
/ I. I. Ryzhkov, S. P. Tsarev // Phys. Fluids. - 2015. - Vol. 27, Is. 7. - Ст. 072103, DOI 10.1063/1.4926891
. - ISSN 1070-6631
Кл.слова (ненормированные):
Binary mixtures -- Temperature -- Weightlessness -- Concentration gradients -- Conservation of mass -- Critical temperature difference -- Interfacial concentrations -- Latent heat release -- Mechanical equilibrium -- Onset of convection -- Temperature differences -- Mixtures
Аннотация: The linear stability of mechanical equilibrium in a two-layer system formed by different phases of the same binary mixture is investigated. The temperature difference is applied to the layers by heating and cooling the opposite rigid boundaries. In the state of mechanical equilibrium, the applied temperature gradient induces concentration gradients due to the Soret effect. The conservation of mass for the mixture components leads to the dependence of layer thicknesses on the applied temperature difference. In weightlessness, the main mechanisms of instability in the considered system are related to phase change and Marangoni effect. The calculations are performed for cyclohexane-methanol binary mixture, which has a liquid-liquid miscibility gap. The analytical solution of amplitude equations for monotonic perturbations is found and expression for the critical temperature difference is derived. It is shown that the phase change instability is long-wave and favoured when the difference between interfacial concentrations in the basic state decreases. When the Marangoni effect is taken into account, additional monotonic and oscillatory modes appear. They result from the interplay between thermocapillarity and phase change with latent heat release/absorption. The most unstable monotonic and oscillatory modes are identified depending on the heating regime and relative thickness of the layers. © 2015 AIP Publishing LLC.
Scopus,
WOS
Держатели документа:
Institute of Computational Modelling SB RAS, Akademgorodok, Krasnoyarsk, Russian Federation
Institute of Space and Information Technologies, Siberian Federal University, 79 Svobodny pr., Krasnoyarsk, Russian Federation
Доп.точки доступа:
Tsarev, S.P.; Рыжков, Илья Игоревич
Кл.слова (ненормированные):
Binary mixtures -- Temperature -- Weightlessness -- Concentration gradients -- Conservation of mass -- Critical temperature difference -- Interfacial concentrations -- Latent heat release -- Mechanical equilibrium -- Onset of convection -- Temperature differences -- Mixtures
Аннотация: The linear stability of mechanical equilibrium in a two-layer system formed by different phases of the same binary mixture is investigated. The temperature difference is applied to the layers by heating and cooling the opposite rigid boundaries. In the state of mechanical equilibrium, the applied temperature gradient induces concentration gradients due to the Soret effect. The conservation of mass for the mixture components leads to the dependence of layer thicknesses on the applied temperature difference. In weightlessness, the main mechanisms of instability in the considered system are related to phase change and Marangoni effect. The calculations are performed for cyclohexane-methanol binary mixture, which has a liquid-liquid miscibility gap. The analytical solution of amplitude equations for monotonic perturbations is found and expression for the critical temperature difference is derived. It is shown that the phase change instability is long-wave and favoured when the difference between interfacial concentrations in the basic state decreases. When the Marangoni effect is taken into account, additional monotonic and oscillatory modes appear. They result from the interplay between thermocapillarity and phase change with latent heat release/absorption. The most unstable monotonic and oscillatory modes are identified depending on the heating regime and relative thickness of the layers. © 2015 AIP Publishing LLC.
Scopus,
WOS
Держатели документа:
Institute of Computational Modelling SB RAS, Akademgorodok, Krasnoyarsk, Russian Federation
Institute of Space and Information Technologies, Siberian Federal University, 79 Svobodny pr., Krasnoyarsk, Russian Federation
Доп.точки доступа:
Tsarev, S.P.; Рыжков, Илья Игоревич