scholarly journals A model of so-called "Zebra" emissions in solar flare radio burst continua

2011 ◽  
Vol 29 (9) ◽  
pp. 1673-1682 ◽  
Author(s):  
R. A. Treumann ◽  
R. Nakamura ◽  
W. Baumjohann
Keyword(s):  
Narrow Band ◽  
Radio Continuum ◽  
Radio Emissions ◽  
Zebra Pattern ◽  
Cyclotron Maser ◽  
Broadband Radio ◽  
Ion Cyclotron ◽  
Electric Potential Field ◽  
Cyclotron Harmonics ◽  
Electron Maser

Abstract. A simple mechanism for the generation of electromagnetic "Zebra" pattern emissions is proposed. "Zebra" bursts are regularly spaced narrow-band radio emissions on the otherwise broadband radio continuum emitted by the active solar corona. The mechanism is based on the generation of an ion-ring distribution in a magnetic mirror geometry in the presence of a properly directed field-aligned electric potential field. Such ion-rings or ion-conics are well known from magnetospheric observations. Under coronal conditions they may become weakly relativistic. In this case the ion-cyclotron maser generates a number of electromagnetic ion-cyclotron harmonics which modulate the electron maser emission. The mechanism is capable of switching the emission on and off or amplifying it quasi-periodically which is a main feature of the observations.

Magnetic drift induced ion-cyclotron maser instability

1987 ◽  
Vol 30 (3) ◽  
pp. 804 ◽  
Author(s):  
K. T. Tsang ◽  
B. Hafizi
Keyword(s):  
Cyclotron Maser ◽  
Ion Cyclotron

scholarly journals Numerical simulations of unbounded cyclotron-maser emissions

2013 ◽  
Vol 79 (6) ◽  
pp. 999-1001 ◽  
Author(s):  
DAVID C. SPEIRS ◽  
S. L. McCONVILLE ◽  
K. M. GILLESPIE ◽  
A. D. R. PHELPS ◽  
K. RONALD
Keyword(s):  
Radio Emission ◽  
Numerical Simulations ◽  
Source Region ◽  
Radio Emissions ◽  
Cyclotron Maser ◽  
Thermal Radio ◽  
Thermal Radio Emission ◽  
Electron Cyclotron Masers ◽  
Coupling Characteristics ◽  
Significant Bearing

AbstractNumerical simulations have been conducted to study the spatial growth rate and emission topology of the cyclotron-maser instability responsible for stellar/planetary auroral magnetospheric radio emission and intense non-thermal radio emission in other astrophysical contexts. These simulations were carried out in an unconstrained geometry, so that the conditions existing within the source region of some natural electron cyclotron masers could be more closely modelled. The results have significant bearing on the radiation propagation and coupling characteristics within the source region of such non-thermal radio emissions.

The excitation of obliquely propagating fast Alfvén waves at fusion ion cyclotron harmonics

1994 ◽  
Vol 1 (6) ◽  
pp. 1918-1928 ◽  
Author(s):  
R. O. Dendy ◽  
C. N. Lashmore‐Davies ◽  
K. G. McClements ◽  
G. A. Cottrell
Keyword(s):  
Alfven Waves ◽  
Alfvén Waves ◽  
Ion Cyclotron ◽  
Cyclotron Harmonics

scholarly journals On the Nature of Radio Emission of Late-Type Giants

1989 ◽  
Vol 106 ◽  
pp. 383-383
Author(s):  
G.M. Rudnitskij
Keyword(s):  
Radio Emission ◽  
Front Surface ◽  
Stellar Atmosphere ◽  
Variable Stars ◽  
Radio Continuum ◽  
Radio Flux ◽  
Cyclotron Maser ◽  
Thermal Radio Emission ◽  
Circumstellar Gas ◽  
Period Variable

Long-period variable stars (LPV's) are considered. Pulsations of the surface of such a star result in formation in the stellar atmosphere of a shock wave in each cycle of the star's variability, ionizing the circumstellar gas which, recombining, gives rise to emissions in optical lines hydrogen and metals. I show the recombining layer behind the shock front to be optically thick in the free-free continuum at the radio wavelengths as short as 1 cm. At the gas temperatures behind the front T = 20000 K, the radio flux density at 1 cm from the front surface at a distance of a few hundred parsees will be several or several tens of mjy. So far, the only positive result of searches for LPVS’ radio continuum is the detection of radio flux from R Aql, obtained at different epochs by several authors. In October 1978 R Aql showed radio emission of 5.3 mjy at 14.9 GHz (Bowers and Kundu, 1979), and in August 1985 - 0.54 mjy at the same frequency (Drake et al.. 1987); these figures are consistent with our model. Besides that, R Aql experienced stronger radio flares at longer wavelengths, up to a few hundred mjy (Woodsworth and Hughes, 1973; Estalella et al.. 1983); these cannot be explained by thermal radio emission and require a nonthermal mechanism (synchrotron or cyclotron maser).

Research on Variable-Frequency-Point Variable-Bandwidth Wireless Broadband Radio Frequency Chip and its Application in the Smart Grid

2011 ◽  
Vol 347-353 ◽  
pp. 3107-3115
Author(s):  
Zi Guan Zhou ◽  
Xiao Shan Pan ◽  
Shu Gang Yin ◽  
Wei Li Ren ◽  
Sheng Bo Sun ◽  
...  
Keyword(s):  
Smart Grid ◽  
Power System ◽  
Radio Frequency ◽  
Communication Technology ◽  
Data Transmission ◽  
Narrow Band ◽  
Frequency Range ◽  
Broadband Radio ◽  
Wireless Broadband ◽  
Residential Electricity

With the development of the smart grid, residential electricity services have a higher bandwidth and frequency requirement to the power system communication , the existing power 230MHz narrow-band data transmission communication has been unable to meet the needs of the two-way interaction between the users and the smart grid. In terms of current communication technology in the power system, this paper introduces a wireless broadband radio frequency chip ,which supports 100MHz to 1.2GHz frequency range, and 5KHz to 2MHz tunable bandwidth.With the chip embedded in intelligent electricity interactive terminals, distribution monitoring terminals and other devices, it can achieve flexible and intelligent electricity services. This paper describes the architecture of the RF chip,and gives key technology solutions such as broadband matching, adjustable IF bandwidth of the channel, sums up the advantages of the chip,presents the application in the smart grid. The analysis finds that the chip has a variety of charateristics such as high integration, good redundancy, versatility, flexibility and so on, and can satisfy the growing application needs of power speacial network,and has an extremely promising market .

scholarly journals Zebra pattern in decametric radio emission of Jupiter

2018 ◽  
Vol 610 ◽  
pp. A69 ◽  
Author(s):  
M. Panchenko ◽  
S. Rošker ◽  
H. O. Rucker ◽  
A. Brazhenko ◽  
P. Zarka ◽  
...  
Keyword(s):  
Radio Emission ◽  
Radio Telescope ◽  
Narrow Band ◽  
Central Meridian ◽  
Frequency Interval ◽  
Frequency Range ◽  
Systematic Analysis ◽  
Zebra Pattern ◽  
Left Handed ◽  
New Type

We report the systematic analysis of zebra-like fine spectral structures in decametric frequency range of Jovian radio emission. Observations were performed by the large ground-based radio telescope URAN-2 during three observation campaigns between, Sep., 2012, and May, 2015. In total, 51 zebra pattern (ZP) events were detected. These rare fine radio features are observed in frequency range from 12.5 to 29.7 MHz as quasi-harmonically related bands of enhanced brightness. ZPs are strongly polarized radio emission with a duration from 20 s to 290 s and flux densities ~105−106 Jy (normalized to 1 AU), that is, 1–2 orders lower than for Io-decametric radio emission (DAM). Occurrence of the events does not depend on the position of Io satellite but is strongly controlled by the Jovian central meridian longitude (CML). ZPs are mainly detected in two active sectors of Jovian CMLs: 100∘ to 160∘ for Northern sources (right-handed polarized) and 300∘ and 60∘ (via 360∘) for the Southern sources (left-handed). The frequency interval between neighboring stripes is from 0.26 to 1.5 MHz and in most cases this interval increases with frequency. We discussed the double plasma resonance with electrons or ions as a possible source of the ZPs. The performed analysis of the observations allows us to conclude that the observed ZPs are a new type of narrow band spectral structures in the Jovian DAM.

High-efficiency narrow-band free-electron maser using a Bragg cavity with a phase discontinuity in the ripples

1999 ◽  
Vol 25 (6) ◽  
pp. 429-432 ◽  
Author(s):  
N. Yu. Peskov ◽  
N. S. Ginzburg ◽  
A. A. Kaminskii ◽  
A. K. Kaminskii ◽  
S. N. Sedykh ◽  
...  
Keyword(s):  
Free Electron ◽  
High Efficiency ◽  
Narrow Band ◽  
Free Electron Maser ◽  
Phase Discontinuity ◽  
Electron Maser
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