16 research outputs found
Alfven Wave Generation by means of High Orbital Injection of Barium Cloud in Magnetosphere
An analysis of the Alfven wave generation associated with the barium vapor
release at altitudes ~ 5.2 Earth's radii (ER) in the magnetosphere is
presented. Such injections were executed in G-8 and G-10 experiments of the
Combined Radiation and Radiation Effects Satellite (CRRES) mission. It is shown
that the generation of Alfven waves is possible during the total time of plasma
expansion. The maximum intensity of these waves corresponds to the time of
complete retardation of the diamagnetic cavity created by the expansion of
plasma cloud. The Alfven wave exhibits a form of an impulse with an effective
frequency ~ 0.03-0.05 Hz. Due to the background conditions and wave frequency,
the wave mainly oscillates along the geomagnetic field between the mirror
reflection points situated at ~ 0.7 ER. The wave amplitude is sufficient to the
generation of plasma instabilities and longitudinal electric field, and to an
increase in the longitudinal energy of electrons to ~ 1 keV. These processes
are the most probable for altitudes ~ 1 ER. The auroral kilometric radiation
(AKR) at frequencies ~ 100 kHz is associated with these accelerated electrons.
The acceleration of electrons and AKR can be observed almost continuously
during the first minute and then from time to time with pauses about 35-40 s
till 6-8 min after the release. The betatron acceleration of electrons at the
recovery of the geomagnetic field is also discussed. This mechanism could be
responsible for the acceleration of electrons resulting in the aurorae and
ultra short radio wave storm at frequencies 50-300 MHz observed at the 8-10th
min after the release.Comment: Presented at COSPAR 200
Neutrino kinetics in a magnetized dense plasma
The relativistic kinetic equations (RKE) for lepton plasma in the presence of
a strong external magnetic field are derived in Vlasov approximation. The new
RKE for the electron spin distribution function includes the weak interaction
with neutrinos originated by the axial vector current () and provided
by the parity nonconservation. In a polarized electron gas Bloch equation
describing the evolution of the magnetization density perturbation is derived
from the electron spin RKE being modified in the presence of neutrino fluxes.
Such modified hydrodynamical equation allows to obtain the new dispersion
equation in a magnetized plasma from which the neutrino driven instability of
spin waves can be found. It is shown that this instability is more efficient
e.g. in a magnetized supernova than the analogous one for Langmuir waves
enhanced in an isotropic plasma.Comment: 20 pages, no figures, added subsection 2.3 about the lepton current
conservation, to be published in Astroparticle Physic
Plasma wave instabilities induced by neutrinos
Quantum field theory is applied to study the interaction of an electron
plasma with an intense neutrino flux. A connection is established between the
field theory results and classical kinetic theory. The dispersion relation and
damping rate of the plasma longitudinal waves are derived in the presence of
neutrinos. It is shown that Supernova neutrinos are never collimated enough to
cause non-linear effects associated with a neutrino resonance. They only induce
neutrino Landau damping, linearly proportional to the neutrino flux and
.Comment: 18 pages, 3 figures, title and references correcte
The electromagnetic vertex of neutrinos in an electron background and a magnetic field
We study the electromagnetic vertex function of a neutrino that propagates in
an electron background in the presence of a static magnetic field. The
structure of the vertex function under the stated conditions is determined and
it is written down in terms of a minimal and complete set of tensors. The
one-loop expressions for all the form factors is given, up to terms that are
linear in the magnetic field, and the approximate integral formulas that hold
in the long wavelength limit are obtained. We discuss the physical
interpretation of some of the form factors and their relation with the concept
of the neutrino induced charge. The neutrino acquires a longitudinal and a
transverse charge, due to the fact that the form factors depend on the
transverse and longitudinal components of the photon momentum independently. We
compute those form factors explicitly in various limiting cases and find that
the longitudinal and transverse charge are the same for the case of a
non-relativistic electron gas, but not otherwise.Comment: 18 pages. Revtex4, axodra
An Extreme Solar Event of 20 January 2005: Properties of the Flare and the Origin of Energetic Particles
The extreme solar and SEP event of 20 January 2005 is analyzed from two
perspectives. Firstly, we study features of the main phase of the flare, when
the strongest emissions from microwaves up to 200 MeV gamma-rays were observed.
Secondly, we relate our results to a long-standing controversy on the origin of
SEPs arriving at Earth, i.e., acceleration in flares, or shocks ahead of CMEs.
All emissions from microwaves up to 2.22 MeV line gamma-rays during the main
flare phase originated within a compact structure located just above sunspot
umbrae. A huge radio burst with a frequency maximum at 30 GHz was observed,
indicating the presence of a large number of energetic electrons in strong
magnetic fields. Thus, protons and electrons responsible for flare emissions
during its main phase were accelerated within the magnetic field of the active
region. The leading, impulsive parts of the GLE, and highest-energy gamma-rays
identified with pi^0-decay emission, are similar and correspond in time. The
origin of the pi^0-decay gamma-rays is argued to be the same as that of lower
energy emissions. We estimate the sky-plane speed of the CME to be 2000-2600
km/s, i.e., high, but of the same order as preceding non-GLE-related CMEs from
the same active region. Hence, the flare itself rather than the CME appears to
determine the extreme nature of this event. We conclude that the acceleration,
at least, to sub-relativistic energies, of electrons and protons, responsible
for both the flare emissions and the leading spike of SEP/GLE by 07 UT, are
likely to have occurred simultaneously within the flare region. We do not rule
out a probable contribution from particles accelerated in the CME-driven shock
for the leading GLE spike, which seemed to dominate later on.Comment: 34 pages, 14 Postscript figures. Solar Physics, accepted. A typo
corrected. The original publication is available at
http://www.springerlink.co
The Impact of Solar Activity on the Earth Upper Atmosphere as Inferred from the CORONAS-F Scientific Experiments
Methods for creating the self-regulating mechanisms of passive systems for ensuring thermal regime of devices for space application
The current system generated by the porcupine artificial ion beam in the ionosheric background plasma Contributed paper
SIGLETIB: RN 9303 (49) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman