On the stability of cosmic ray dominated shocks

1992 ◽  
Author(s):  
Hyesung Kang ◽  
Dongsu Ryu ◽  
T. W. Jones
Keyword(s):  
Cosmic Ray ◽  
The Stability

scholarly journals Cosmic ray tracking to monitor the stability of historical buildings: a feasibility study

2019 ◽  
Vol 30 (4) ◽  
pp. 045901 ◽  
Author(s):  
G Bonomi ◽  
M Caccia ◽  
A Donzella ◽  
D Pagano ◽  
V Villa ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Cosmic Ray ◽  
Historical Buildings ◽  
The Stability

The stability of cosmic-ray-dominated shocks - A secondary instability

1993 ◽  
Vol 405 ◽  
pp. 199 ◽  
Author(s):  
Dongsu Ryu ◽  
Hyesung Kang ◽  
T. W. Jones
Keyword(s):  
Cosmic Ray ◽  
Secondary Instability ◽  
The Stability

A cosmic-ray-driven plasma instability

1989 ◽  
Vol 41 (1) ◽  
pp. 89-95 ◽  
Author(s):  
G. P. Zank
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Thermal Plasma ◽  
Cosmic Ray ◽  
Mhd Equations ◽  
Mutual Interaction ◽  
Shock Acceleration ◽  
Wave Effects ◽  
The Stability

The stability of the MHD equations describing the mutual interaction of cosmic rays, thermal plasma, magnetic field and Alfvén waves used in cosmic-ray-shock acceleration theory (e.g. McKenzie & Völk 1982) is analysed for linear compressive instabilities. It is found that the inclusion of wave effects implies that the forward propagating sub-Alfvénic mode is unstable on wavelength scales greater than 1 parsec. The role of the instability in astrophysical models is considered.

The interaction of long-wavelength compressive waves with a cosmic ray shock

1987 ◽  
Vol 37 (3) ◽  
pp. 363-372 ◽  
Author(s):  
G. P. Zank ◽  
J. F. Mckenzie
Keyword(s):  
Dispersion Equation ◽  
Transmission Coefficient ◽  
Cosmic Ray ◽  
Long Wavelength ◽  
The Stability ◽  
Two Fluid

This paper investigates the stability of a cosmic ray shock to long-wavelength perturbations. The problem is formulated in terms of finding the transmission coefficient for compressive waves across a cosmic ray shock by solving the generalized, two-fluid Rankine-Hugoniot relations. For strong shocks, the transmission coefficient confirms that compressive waves can undergo considerable amplification on passage through such shocks. The resonances of the transmission coefficient provides us with the dispersion equation governing the stability of the shock to long-wavelength ripple-like distortions. By using the principle of the argument method, it is established that cosmic ray shocks are stable.

Short-wavelength compressive instabilities in cosmic ray shocks and heat conduction flows

1987 ◽  
Vol 37 (3) ◽  
pp. 347-361 ◽  
Author(s):  
G. P. Zank ◽  
J. F. Mckenzie
Keyword(s):  
Solar Wind ◽  
Heat Conduction ◽  
Cosmic Ray ◽  
Theoretical Models ◽  
Dissipative Heating ◽  
Wave Action ◽  
Background Flow ◽  
Wave Amplification ◽  
Shock Transition ◽  
The Stability

In this paper we discuss the stability of three genetically similar non-uniform flows to compressive disturbances whose wavelengths are much shorter than the length scales characterizing the background flow. The results are relevant to theoretical models of cosmic ray shocks and solar wind type flows involving heat conduction. A JWKB expansion solution yields an equation which determines how the amplitudes of the perturbations may grow (or decay) as they propagate within such structures. It is shown that, in all three of the models considered, the perturbations exhibit spatial growth if the background flow is sufficiently supersonic and decelerating. The associated equations describing the evolution of the wave action are also studied with a view to deciding whether or not the behaviour of this attractive variable can provide an unambiguous answer to the question of stability. In the case of a shock transition dominated by heat conduction, it is shown that the effects of dissipative heating within the transition more than offset those of wave growth, with the result that wave amplification is accompanied by wave action decay. Therefore in general it would appear that the wave action equation alone cannot unambiguously settle stability questions.

scholarly journals Stochastic electron motion driven by space plasma waves

2014 ◽  
Vol 21 (1) ◽  
pp. 61-85 ◽  
Author(s):  
G. V. Khazanov ◽  
A. A. Tel’nikhin ◽  
T. K. Kronberg
Keyword(s):  
Langmuir Wave ◽  
Nonlinear Resonance ◽  
Cosmic Ray ◽  
Space Plasma ◽  
Plasma Waves ◽  
Relativistic Electrons ◽  
Stochastic Motion ◽  
Hamiltonian Chaos ◽  
Radiation Belt Electrons ◽  
The Stability

Abstract. Stochastic motion of relativistic electrons under conditions of the nonlinear resonance interaction of particles with space plasma waves is studied. Particular attention is given to the problem of the stability and variability of the Earth's radiation belts. It is found that the interaction between whistler-mode waves and radiation-belt electrons is likely to involve the same mechanism that is responsible for the dynamical balance between the accelerating process and relativistic electron precipitation events. We have also considered the efficiency of the mechanism of stochastic surfing acceleration of cosmic electrons at the supernova remnant shock front, and the accelerating process driven by a Langmuir wave packet in producing cosmic ray electrons. The dynamics of cosmic electrons is formulated in terms of a dissipative map involving the effect of synchrotron emission. We present analytical and numerical methods for studying Hamiltonian chaos and dissipative strange attractors, and for determining the heating extent and energy spectra.

scholarly journals Multi-point galactic cosmic ray measurements between 1 and 4.5 AU over a full solar cycle

2019 ◽  
Vol 37 (5) ◽  
pp. 903-918 ◽  
Author(s):  
Thomas Honig ◽  
Olivier G. Witasse ◽  
Hugh Evans ◽  
Petteri Nieminen ◽  
Erik Kuulkers ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Galactic Cosmic Rays ◽  
Radiation Environment ◽  
Radiation Data ◽  
Rosetta Mission ◽  
The Stability ◽  
Cross Calibration ◽  
Galactic Cosmic Ray

Abstract. The radiation data collected by the Standard Radiation Environment Monitor (SREM) aboard ESA missions INTEGRAL (INTErnational Gamma-Ray Astrophysics Laboratory), Rosetta, Herschel, Planck and Proba-1, and by the high-energy neutron detector (HEND) instrument aboard Mars Odyssey, are analysed with an emphasis on characterising galactic cosmic rays (GCRs) in the inner heliosphere. A cross calibration between all sensors was performed for this study, which can also be used in subsequent works. We investigate the stability of the SREM detectors over long-term periods. The radiation data are compared qualitatively and quantitatively with the corresponding solar activity. Based on INTEGRAL and Rosetta SREM data, a GCR helioradial gradient of 2.96 % AU−1 is found between 1 and 4.5 AU. In addition, the data during the last phase of the Rosetta mission around comet 67P/Churyumov–Gerasimenko were studied in more detail. An unexpected yet unexplained 8 % reduction of the Galactic Comic Ray flux measured by Rosetta SREM in the vicinity of the comet is noted.

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