The Time Evolution Effects in Fermi Acceleration by Shock Waves (Ⅲ)
-
摘要: 本文研究了在考虑粒子的扩散系数随动量变化条件下的激波费米加速的时间演化过程,对各种源粒子时间及空间分布分别求得被加速粒子的能谱和平均动能的时间演化.通过数值计算,并与粒子扩散系数和动量无关的情形相比较,结果表明:扩散系数随动量变化使高能粒子不易得到加速.在扩散系数按X～pn随动量变化的情况下,本文得到了平均动能按
～t2/n规律随时间增加. Abstract: In this paper, a study of the time evolution processes of Fermi acceleration by shock waves in the case of the diffusion coefficient of particles varies with momentum is made. The evolution of the energy spectra and the kinetic energy of accelerated particles with various temporal and spacial distributions of source particles are obtained. The results of calculation show that the energetic particles are not as easy to be accelerated as comparied with the case of the diffusion coefficient independent on momentum. The average kinetic energy increases with time according to the law of-t2/n, provided that the diffusion coefficitnt varies with the momentum in the form of x-Pn. -
-
计量
- 文章访问数: 2676
- HTML全文浏览量: 157
- PDF下载量: 741
-
被引次数:
0(来源:Crossref)
0(来源:其他)
下载:
