Acceleration of energetic particles by shock waves from large solar flares

1990 ◽  
Vol 358 ◽  
pp. L63 ◽  
Author(s):  
Donald V. Reames
1978 ◽  
Vol 83 (A3) ◽  
pp. 1035 ◽  
Author(s):  
G. N. Zastenker ◽  
V. V. Temny ◽  
C. D'Uston ◽  
J. M. Bosqued
Keyword(s):  

1978 ◽  
Vol 3 (3) ◽  
pp. 236-238
Author(s):  
V. M. Gubchenko ◽  
V. V. Zaitsev

Lin and Hudson (1976) have recently analysed non-thermal processes in proton flares, using observations of a series of major events in August 1972. They concluded that the 10–100 keV electrons accelerated during the flash phase account for the bulk of the total energy of a large proton flare (about 1032 – 1033 ergs); that most protons are accelerated later than the 10 — 100 keV electrons; and that most energetic protons escape to the interplanetary medium. Their conclusions with regard to proton acceleration are supported firstly by the delay of the maximum of γ-ray emission by 3-5 minutes after the maximum of X-ray emission, and secondly by the satisfactory agreement between the 7-ray spectrum and the thin-target model of emission. The energetic protons contain a very small fraction of the total flare energy (of the order of 10-5).


2001 ◽  
Vol 547 (2) ◽  
pp. 1159-1166 ◽  
Author(s):  
X. Y. Wang ◽  
C. S. Wu ◽  
S. Wang ◽  
J. K. Chao ◽  
Y. Lin ◽  
...  

Atoms ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 104 ◽  
Author(s):  
Donald V. Reames

From a turbulent history, the study of the abundances of elements in solar energetic particles (SEPs) has grown into an extensive field that probes the solar corona and physical processes of SEP acceleration and transport. Underlying SEPs are the abundances of the solar corona, which differ from photospheric abundances as a function of the first ionization potentials (FIPs) of the elements. The FIP-dependence of SEPs also differs from that of the solar wind; each has a different magnetic environment, where low-FIP ions and high-FIP neutral atoms rise toward the corona. Two major sources generate SEPs: The small “impulsive” SEP events are associated with magnetic reconnection in solar jets that produce 1000-fold enhancements from H to Pb as a function of mass-to-charge ratio A/Q, and also 1000-fold enhancements in 3He/4He that are produced by resonant wave-particle interactions. In large “gradual” events, SEPs are accelerated at shock waves that are driven out from the Sun by wide, fast coronal mass ejections (CMEs). A/Q dependence of ion transport allows us to estimate Q and hence the source plasma temperature T. Weaker shock waves favor the reacceleration of suprathermal ions accumulated from earlier impulsive SEP events, along with protons from the ambient plasma. In strong shocks, the ambient plasma dominates. Ions from impulsive sources have T ≈ 3 MK; those from ambient coronal plasma have T = 1 – 2 MK. These FIP- and A/Q-dependences explore complex new interactions in the corona and in SEP sources.


2016 ◽  
Vol 831 (2) ◽  
pp. 195 ◽  
Author(s):  
P. Tooprakai ◽  
A. Seripienlert ◽  
D. Ruffolo ◽  
P. Chuychai ◽  
W. H. Matthaeus

2011 ◽  
Vol 738 (2) ◽  
pp. 168 ◽  
Author(s):  
Pingbing Zuo ◽  
Ming Zhang ◽  
Konstantin Gamayunov ◽  
Hamid Rassoul ◽  
Xi Luo

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