宇宙中高能带电粒子的加速
摘要
The origin of energetic particles is the key issue of high-energy solar physics and astrophysics. Under explosive astrophysical environment, charged particles in the background plasma can be accelerated by electric fields to very high energies. Based on the characteristics of the particle and electric field interactions, one may identify several acceleration mechanisms: Wave-particle resonance interaction, acceleration by electric field parallel to the magnetic field, and acceleration associated with the magnetic field curvature and/or gradient etc. Based on the macroscopic sources of free energies for the particle acceleration, several particle acceleration theories have been developed such as the stochastic particle acceleration, diffusive shock acceleration and acceleration in magnetic reconnection etc. These theories have different assumptions and characteristics and find applications in different astrophysical environment. With the observational advance in high-energy astrophysics, better understanding of varieties of physical processes in explosive astrophysical phenomena can be obtained via detailed analyses of the emission characteristics and the acceleration of high-energy particles.