scholarly journals The role of ionization in the shock acceleration theory

2011 ◽  
Author(s):  
Giovanni Morlino
Keyword(s):  
2017 ◽  
Vol 13 (S335) ◽  
pp. 43-48 ◽  
Author(s):  
Alexei Struminsky

AbstractAt present two concurrent paradigms of solar energetic particle (SEP) origin exist: acceleration directly in the flare site or by the shock wave of coronal mass ejection (CME). Active discussions on a relative role of flares and coronal mass ejections for SEP acceleration and propagation are continuous until now. In my opinion only future observations of solar high energy γ–emission with better spectral, spatial and temporal resolution may clarify this issue. In my report I discuss possible signatures of the flare and shock acceleration processes. What is a picture provided by the current instruments? What can we expect to observe with a perfect instrument in high energy gamma rays in one or another case on a time scale of impulsive and long decay flare phases?


1995 ◽  
Vol 22 (13) ◽  
pp. 1809-1812 ◽  
Author(s):  
Stephen H. Brecht ◽  
Mark E. Pesses ◽  
Imke de Pater ◽  
N. T. Gladd ◽  
John G. Lyon

1989 ◽  
Vol 41 (1) ◽  
pp. 89-95 ◽  
Author(s):  
G. P. Zank

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.


2011 ◽  
Vol 21 (3) ◽  
pp. 199
Author(s):  
Doan Kim The ◽  
Pham Tuan Anh ◽  
Pham Ngoc Diep ◽  
Pham Ngoc Dong ◽  
Nguyen Van Hiep ◽  
...  

A simple numerical simulation of the mechanism of diffusive shock acceleration, responsible for the acceleration of cosmic rays in the environment of young Super Nova Remnants, is presented. The relative roles of a uniform magnetic field component, inherited from the parent collapsed star, and of magnetic turbulences, known to be present in the vicinity of the shock, are investigated. It is shown that a uniform magnetic field allows for only doubling the energy of the cosmic particle. Important accelerations require the simultaneous presence of magnetic field turbulences at a scale commensurable with its Larmor radius.


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