Lifetimes of Trapped Radiation Belt Particles Determined by Coulomb Scattering
Lifetimes of Trapped Radiation Belt Particles Determined by Coulomb Scattering
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DOI：
10.1063/1.1705940
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发表时间：
1959
影响因子：
4.6
通讯作者：
R. C. Wentworth;W. Macdonald;S. Singer
中科院分区：
文献类型：
--
作者：
R. C. Wentworth;W. Macdonald;S. Singer
一旦进入俘获轨道，质子和电子就会被严格地困在地球的偶极磁场中。然而，存在各种限制其寿命的机制，例如与地球外层大气中的原子和离子的碰撞，电荷交换和水磁波的散射。本文只考虑这些粒子被电离氢和外层大气的电子成分散射的影响。然而，中性原子的散射效应可以通过在散射公式中用原子半径代替德拜屏蔽长度来定性地考虑。用Fokker - Planck方程推导了由于小角度单粒子库仑碰撞引起的分布函数变化的表达式。由这一机制确定的质子和电子的寿命上限是它们初始能量的函数。
Once introduced into captive orbits, protons and electrons should be strictly trapped in the earth's dipole magnetic field. However, various mechanisms exist which limit their lifetimes, such as collisions with atoms and ions in the earth's outer atmosphere, charge exchange, and scattering by hydromagnetic waves. This paper considers only the effect of the scattering of these particles by the ionized hydrogen and electron components of the outer atmosphere. However, the effect of scattering from neutral atoms can be qualitatively taken into account by using the radius of the atom in place of the Debye shielding length in the scattering formulas. The Fokker‐Planck equation has been used to derive an expression for the change in the distribution function due to small‐angle, single‐particle Coulomb collisions. Upper lifetime limits, as determined by this mechanism, of both protons and electrons are derived as functions of their initial energies.