WEST
• 回旋 • 往返 • 漂移
Van Allen辐射带的稳定存在反映了纵向不变量的近似守恒, Inner and outer radiation belts: • The outer belt: mainly electrons (0.1–10 MeV) (3 to 10Re) • The inner belt: mainly protons (0.1 to 1.5 Re) >100 MeV & electrons (hundreds of kev). • The relative drift between the ions and electrons produces the ring current in the geomagnetosphere. • A gap between the inner and outer Van Allen belts, sometimes called safe zone or safe slot, is caused by the very low frequency (VLF) waves which scatter particles in pitch angle which results in the loss of particles to the atmosphere
2.3 曲率漂移 粒子被洛仑兹力约束在磁力线上, 导心沿着力线 平行运动; 若磁力线是弯曲的，则在导心坐标系中， 粒子将感受到惯性离心力，并产生曲率漂移。 惯性离心力可表示为
曲率半径
漂移速度：
考虑势场(无旋场) 或 无力场(电流与磁场平行非均匀的.
In 1990, the satellite Combined Release and Radiation Effects Satellite (CRRES) discovered a third radiation belt located between the inner and outer Van Allen belts. Also, around May 8, 1998, there were a series of large, solar disturbances that caused a new radiation belt to form in the so-called “slot region” between the inner and outer van Allen belts. The new belt eventually disappeared once the solar activity subsided. Nuclear tests in space artificial radiation belts. Starfish Prime, damaged or destroyed as many as one third of the satellites in low earth orbit at the time (1962?).
