scholarly journals Low-frequency Hall current instability in a dusty plasma

2000 ◽  
Vol 105 (A10) ◽  
pp. 23135-23139 ◽  
Author(s):  
M. Rosenberg ◽  
P. K. Shukla
Keyword(s):  
Dusty Plasma ◽  
Hall Current ◽  
Low Frequency ◽  
Current Instability

Low-frequency wave modulations in an electronegative dusty plasma in the presence of charge variations

2011 ◽  
Vol 84 (6) ◽  
Author(s):  
Samiran Ghosh ◽  
Subrata Sarkar ◽  
Manoranjan Khan ◽  
M. R. Gupta
Keyword(s):  
Dusty Plasma ◽  
Low Frequency ◽  
Frequency Wave

scholarly journals Two-point observations of low-frequency waves at 67P/Churyumov-Gerasimenko during the descent of PHILAE: comparison of RPCMAG and ROMAP

2016 ◽  
Vol 34 (7) ◽  
pp. 609-622 ◽  
Author(s):  
Ingo Richter ◽  
Hans-Ulrich Auster ◽  
Gerhard Berghofer ◽  
Chris Carr ◽  
Emanuele Cupido ◽  
...  
Keyword(s):  
Low Frequency ◽  
Minimum Variance ◽  
Wave Source ◽  
Frequency Wave ◽  
Final Destination ◽  
Connection Line ◽  
New Type ◽  
Current Instability ◽  
Comet 67P ◽  
Low Frequency Waves

Abstract. The European Space Agency's spacecraft ROSETTA has reached its final destination, comet 67P/Churyumov-Gerasimenko. Whilst orbiting in the close vicinity of the nucleus the ROSETTA magnetometers detected a new type of low-frequency wave possibly generated by a cross-field current instability due to freshly ionized cometary water group particles. During separation, descent and landing of the lander PHILAE on comet 67P/Churyumov-Gerasimenko, we used the unique opportunity to perform combined measurements with the magnetometers onboard ROSETTA (RPCMAG) and its lander PHILAE (ROMAP). New details about the spatial distribution of wave properties along the connection line of the ROSETTA orbiter and the lander PHILAE are revealed. An estimation of the observed amplitude, phase and wavelength distribution will be presented as well as the measured dispersion relation, characterizing the new type of low-frequency waves. The propagation direction and polarization features will be discussed using the results of a minimum variance analysis. Thoughts about the size of the wave source will complete our study.

Charge density fluctuation of low frequency in a dusty plasma

1997 ◽  
Vol 40 (2) ◽  
pp. 206-213 ◽  
Author(s):  
Fang Li ◽  
Baowei Lü ◽  
O. Havnes
Keyword(s):  
Charge Density ◽  
Dusty Plasma ◽  
Density Fluctuation ◽  
Low Frequency

Simulations of the ion–dust streaming instability with non-Maxwellian ions

2017 ◽  
Vol 83 (6) ◽  
Author(s):  
K. Quest ◽  
M. Rosenberg ◽  
B. Kercher
Keyword(s):  
Velocity Distribution ◽  
Dusty Plasma ◽  
Density Wave ◽  
Low Frequency ◽  
Ion Distribution ◽  
Ion Flow ◽  
Ion Drift ◽  
Streaming Instability ◽  
Ion Velocity ◽  
Linear Kinetic Theory

The dust acoustic, or dust density, wave is a very low frequency collective mode in a dusty plasma that is associated with the motion of the charged and massive dust grains. An ion flow due to an electric field can excite these waves via an ion–dust streaming instability. Theories of this instability have often assumed a shifted-Maxwellian ion velocity distribution. Recently, the linear kinetic theory of this instability was considered using a non-Maxwellian ion velocity distribution (Kählert, Phys. Plasmas, vol. 22, 2015, 073703). In this paper, we present one-dimensional PIC simulations of the nonlinear development of the ion–dust streaming instability, comparing the results for these two types of ion velocity distributions, for several values of the ion drift speed and collision rate. Parameters are considered that reflect the ordering of plasma and dust quantities in laboratory dusty plasma experiments. It is found that, in general, the wave energy density is smaller in the simulations with a non-Maxwellian ion distribution.

scholarly journals Turbulent Acceleration in Solar Flares

1994 ◽  
Vol 142 ◽  
pp. 623-630
Author(s):  
D. B. Melrose
Keyword(s):  
Solar Flares ◽  
Gamma Ray ◽  
Low Frequency ◽  
Impulsive Phase ◽  
Primary Energy ◽  
Nonthermal Electron ◽  
Relativistic Electrons ◽  
Mhd Turbulence ◽  
Narrow Channels ◽  
Current Instability

AbstractTurbulent acceleration in the impulsive phase of solar flares is reviewed, with the emphasis on bulk energization of nonrelativistic electrons and prompt acceleration of the gamma-ray emitting nonrelativistic ions and relativistic electrons. The primary energy release in a flare cannot be due to collisional dissipation. Anomalous resistivity requires that the current flows in many narrow channels with the current density above threshold for current instability. The bulk energization of the electrons is due to the damping of low-frequency electrostatic turbulence generated by the current instability. This turbulence also limits the rate a nonthermal electron tail forms due to runaway acceleration. Stochastic and gyroresonant acceleration by MHD turbulence are discussed briefly, emphasizing the need for preacceleration. Stochastic acceleration is favorable for the gamma-ray emitting particles only if an adequated source of the MHD turbulence can be identified.Subject headings: acceleration of particles — MHD — Sun: flares — turbulence

Sign in / Sign up

Export Citation Format

Share Document